Jason E

uh What is the difference? I know the 230hp, 5 speed version had the dual-converter exhaust. I'm assuming the cam was the only other difference between these 2 engines?

The reason why I ask is because a guy I know at work has a Camaro enthusiast for a mother, and she has a '91 Z28 305/auto that he's gonna see if she might sell. So what's the deal with the 205hp version of this engine?

------------------
Jason E
"The Cruiser"
'89 Camaro RS 2.8
Hypertech chip/K&N filters/Accel 8.8 wires, Accel Supercoil/RapidFires
Eclipse CD and 100x4 amp/Boston plates and 6x9s
Alpine Alarm, Keyless Entry
"It's for sale"

"The Driver"
'95 Grand Am SE 3.1 Coupe
No mods yet...

I'm the only third genner who's daily driver is faster than their third gen!

[This message has been edited by Jason E (edited February 13, 2001).]

MrJ

The cam is the same, this has been verified... madmax pulled his and proved it. The HP difference comes from the entire exhaust being different... the exhaust manifolds, Y-pipe, and catback are all small, and most likely the same size as what the TBI cars have. They also have one small 2 1/4" TBI cat converter, rather than 2 larger ones. That's the HP difference.

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

Reed

MrJ:

Really? I knew the G92 305's have the dual cats that are the main power differance. I also learned they may have bigger exhaust manifolds that were used on 350's....but is it true that they don't have a better cam than the 205hp 305? I mean the hp jump is 25hp while the 350 is only 10 hp from the non-G92 in some years.

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1989 Iroc-Z. 305TPI 5spd, G92 (230hp/300ft/lbs). 91-92Z28 groundeffects. Corvette Admiral Blue Metallic paint. Thermomaster chip, 160*stat & fan switch, Bosch +4 plugs, MAF screens removed, custom ram air, Flowmaster cat back, K&N, adj. fuel pres. reg.
72,000 miles. SWEET!!

MrJ

yes dude... im virtually certain that the 305 TPI G92 uses the entire 350 TPI exhaust, manifolds and all. I DO know for a fact that my 305 TPI's exhaust is smaller than that of a 350 TPI, the manifolds and Y-pipe are real small, and so was the stock cat. But the cam is the same. The engine is choked like a bastard from the factory. If you were to take a non G92 305 TPI and swap the larger dual cat exhaust on, you'd have the 305 TPI G92 engine, with the higher HP output.

92GTA

iTrader: (11)

What I know from the Pontiac paper work I have is that all TPI 305's were rated at 230 hp for 1992, including my car which is not a G92.......this is striaght from Pontiac. They made special note of it in all of thier 1992 advertisements. Of course this is Pontiac and not chevy and it's also 1992 not 1991.

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www.TransAmGTA.com
1992 GTA (226 made), 1 of only 18 "Dk. Jade Met." 92 GTA's, My Window Sticker, LB9, 700R4 4-Speed, T-Tops, Grey Leather, every available option except J65 and U1A.
Current Mods/Upgrades: 80 Series Dual Outlet Flowmaster, TPIS Air Foil, K&N Air Filter, and Mobil 1.
Future Mods/Upgrades: None but a complete restoration.
Best Track Time: 14.6sec@96.6mph

"If it ain't broke, fix it til it is!"
Webmaster www.TransAmGTA.com
My 3rdGen Firebird Message Board!

[This message has been edited by 92GTA (edited February 13, 2001).]

MrJ

Really? Odd.. but interesting. But I believe it, with the time you ran. But I wonder how that can be.... if yours has the small exhaust like mine does.

[This message has been edited by MrJ (edited February 13, 2001).]

92GTA

iTrader: (11)

MrJ, Pontiac did alot of new trick stuff in 1992....the chassis was redesigned to reduce body flex, the body panels were sealed together differently to reduce inside noise, all 305's went to 230 hp, and the 700R4's were stronger.

There were also quite a few oddities like how you could get a 350 w/T's but only on the Formula with the black wheels, what's that? Now I do know that a handfull of GTA's were also made with the 350 T-Top combo but why was the public or the dealership not informed of this. It makes since though because the chassis were diferent but it seemed that the dealerships were still telling people that it could not be done, it would appear that someone forgot to tell them and Pontiac didn't advertise it. My GTA is also the very last GTA ever built with rear drum brakes which is also wierd.

It would seem that 1992 was a ver odd year for third gen's.......

[This message has been edited by 92GTA (edited February 14, 2001).]

jm91rs

i was just looking at the technical data section. I always thought that the 91 z's had more horsepower than that, at least that's what my friend with one said. So if he has an automatic with the 305, does he only have 205 hp? His car is bone stock, so according to that, he is only at 205.

MrJ

I dunno about most of that man. 1992 was almost a total carryover year from 1991. In 1991 they began using the body glue along the rocker panels. In 1992, they used it throughout the entire car. But they did not redesign the chassis... that would be ludicrous for a car in it's very last year of production. I hadn't heard that about the 700R4, either. How do you explain 230hp in all 305 TPIs, when some have the larger exhaust and dual cats, and others don't? The 350 TPI w/ T-tops Formula was also available in 1991, with the black crosslace wheels like you described.

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

Drew

iTrader: (58)

92GTA posts a lot of invalid or questionable info with no evidence, its nothing new.

------------------
Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6FOR SALE!
92 S10FOR SALE!
98 Grand Am GT

Jason E

Well, I'm totally willing to buy that it's merely the exhaust. Even the tech said "it has the TBI exhaust on it, a little puny one."

So if I do what I was planning (SLP 1 3/4" headers, y-pipe, dual converters and cat back), not only will I make up the 25hp deficit, but I will have more than 230?? Nice!

Any other thoughts?

MrJ

You'd probably be better off with if you were to just get a good catback, single high flow cat, and a set of headers with Y-pipe. The stock exhaust is so restrictive that I think you could easily be pushing 245hp if you do this, since the aftermarket Y-pipe will be larger than the dual cat Y-pipe, and a high flow cat flows about as good as a stock dual cat setup.... and the fact that headers are better than manifolds.

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

Mikos_89

The main differences between the 205hp and 230hp LB9's in '91-'92 is the cam, exhaust, and rear axle ratio.

The 230hp LB9 came equipped with the (L98) high-performance cam. The 205hp LB9 came equipped with the so-called "peanut-cam" borrowed directly from the LG4/LO3. Remember back in '86 when the LB9 had only 190 hp, but in '85 it had 215hp? Well, the 25hp drop was due to the LG4/LO3 cam being used on all non-G92 equipped LB9s after 1985.

The exhaust system is also different between the 205hp LB9 and the 230hp LB9. The 230hp LB9 came equipped with basically the same exhaust as the "dual cat" L98. The 205hp LB9 had a smaller Y-pipe, smaller "primary" pipe after the cats, and most importantly DID NOT include the second converter as in the G92 LB9s and N10 L98s.

The rear axle ratio was also different between the 205hp LB9s and the 230hp LB9s. The 205hp LB9 came equipped with 2.73(AT)/3.08(5sp) gears while the 230hp LB9 had 3.23(AT)/3.45(5sp) gears.

Lastly, there may be some significant changes to the programing in the EPROM between the 205hp and 230hp LB9s.





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'89 GTA: blk on blk with 5.7 liter, T-tops, leather, N10 dual exh with 76,500 original miles. 100% stock including the ZR50 Goodyear "gatorback" tires.

MrJ

WRONG.
Did you copy that off of some website? The cam is the same. Why are you trying to mislead people? The HP difference is entirely due to the exhaust.

I don't know what you are talking about with this 'primary pipe' stuff. I'll work my way from the engine back

The exhaust manifolds are small, TBI manifolds.
The y-pipe is a tiny, 2" TBI y-pipe.
The converter is a 2 1/4" TBI unit.
The stock catback is 2 1/4" as well.

305 TPIs autos have 2.73s. 305 TPI 5 speeds have either 3.08s or 3.42s, depending on whether or not it is a G92 car.

I've toyed with BINs from both 305 TPI auto and 305 TPI 5 speed cars (90-92 of course). The difference in programming is in the spark curve, the manual's is more agressive. Other than that, that's it, besides the obvious stuff like no TCC info for the 5 speed car.

Seriously, I don't know why people get off on misleading people like this. Please do your homework next time.

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

L98ina25thZ28

While I am by no means a know it all, I too find it hard to believe that the two 305s had the same cam. Taken from the Camaro Technical Database...

All 305 TPI (LB9) motors (1985-1992) came with one of two basic cam
grinds. An easy way to identify the type of cam on an LB9 car is to
look at the tach: the lesser cams have a yellow line at 4500 and red
line at 5000; the hotter cams have a yellow line at 5000 and red line
at 5500. See chart at end of chronology for more cam info.

(From Chart)
1990-1992

305 5spd / 305 AT 4500 5000 10088155* .350 .384 179 194 109.0

305 G92 5spd / 350 AT 5000 5500 10111773* .413 .428 202 207 114.5 (116/-116)


I don't know how accurate the database is but I haven't been able to prove it wrong yet.

Why dosen't somebody check the two part numbers?


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--------
'92 Z28
5.7 TPI
T-56 six speed
Pro 5.0 shifter
3.73's
SLP 1-3/4" Headers
SLP Cat-Back
52mm TB
Extrude Honed Intake/Ported plenum
Hypertech Prom

MrJ

It ain't true. The tach isn't an indicator of the cam profile. It is merely part of the base gauge package that all non G92 90-92 305 TPIs have. It also includes the 120MPH speedometer, rather than the 140 unit.

The fact that the 90-92 305 TPI without G92 have the better cam is overwhelmingly obvious. We've had one guy (madmax) pull the cam out of his 91 305 TPI, and he found the L98 cam after measuring it. In addition, the performance of the cars is too close to the 305 TPI 5 speed cars, and in fact is not at all far from that of the early single cat L98s.

Kevin91Z

iTrader: (1)

Did you guys even read this thread before you posted about the cams? Its been talked about for a month now about how the 90-92 305 TPI cars all have the 350 cam. The tech database needs to be updated.

L98ina25thZ28

Where did the Database come from? Is it a trustable source? It seems to have really detailed info but how do we know wether or not it is acurate. I am curious about the part numbers, If I called a dealer and asked for a cam for a '91 Z28 305, would he find multiple part #s? What are the two part numbers in the technical database from?

I know the tach yellow and red lines are different on my '92 L98 145 cluster and my (former) '91 RS LO3 cluster. Since all 305's got the 110 mph cluster but the Z's had different cams from the RS's then either GM used two different 305 tachs or one of the vehicles displayed an incorrect red/yellow line. I don't know what the answer is I am just thinking out loud (on a keyboard?). If all z's had the same cam, then they should have the same red yellow line, right? what is the red yellow line on 305 Z's with and without G92? What is it on the LO3's? What combo did madmax's car have?

MrJ

I just explained this.

If you have an RS, you have the 110 speedometer and 4500/5000 tach.
Ditto for a 305 TPI Z28 without G92.

To tell you the truth, I don't think the inclusion of the 4500/5000 tach on the non-G92 305 TPIs was such a bad idea. On the stock cars, they really don't rev much beyond 4500.... the small exhaust is too much of a limiting factor. But once that bottleneck is removed, the tach no longer reflects the engine's capabilities.

Madmax has an 86 Trans Am with the engine out of a 91 305 TPI Z28, a 5 speed with 3.08s.... not a G92 car.

L98ina25thZ28

Right, but you didn't say what tach a 305 G92 equipped Z has (or maybe you just don't know which is understandable since I don't either). If it has the standard 305 4500/5000 tach then your explanation could hold ground however, that would mean that GM "wrongly" (if that is the right word to use?) labled the 230 horse car's tachs which I doubt they would do. If it has the L98 cam then I would think it should have the 5000/5500.

What about the 3.1 cars, They had the same speedo but what tach did they have? Usually, the six's wind out a little more than the LO3's. I wouldn't be surprised if they had the 5000/5500 tach.

MrJ, I can see you are frustrated. Far be it from me to be the one that makes you pop a ******** or somthing else physically catastrophic like that. I completely accept and understand that you believe what you write. All I ask is that you show me some documented proof about what you write. I just can't accept heresy. We are all just people on the internet chatting. Some have their facts straight, some state wrong things all together, and some like me don't know and are just trying to find the truth. None of us have any reason to believe one another until the proof can be shown. I am not saying you are wrong but I cant believe you yet either.

Guest

The tach has absolutely ZIP to do with the cam. Want proof? I have a pic (although a bad one, I am gonna take a better one) of my stock gauge cluster in my 86TA. Vader has the same car, same engine, and has posted pics of his gauges. His shows yellow at 4500, red at 5000. Mine shows yellow at 5000, red at 5500. His reads to 6000. Mine reads to 8000. The tach has nothing at all to do with the engine, typical GM consistency at its best.

BTW, here are the cam specs I measured about 3 months ago:

Cam specs (format stolen from compcams.com :

ENGINE: CHEVY SM BLK 305-350
INTAKE EXHAUST
VALVE ADJUSTMENT HYD HYD
GROSS VALVE LIFT .413 .428
.006 TAPPET DUR 259 265

VALVE TIMING OPEN CLOSE
AT .006 INT 8 BTDC 71 ABDC
EXH 61 BBDC 24 ATDC
THESE SPECS ARE FOR CAM INSTALLED
AT 119 INTAKE CENTER LINE

INTAKE EXHAUST
DURATION AT .050 202 207
LOBE LIFT .2750 .2850
LOBE SEPARATION 115.5

The exhaust center line is 112. The only spec that was off was the lobe separation, which was off a degree, its supposed to be 114.5. I never found spec for valve timing events, so I assume they are correct since everything else checked out ok.

To say that what we are saying is heresay doesnt mean much. Whats the source of the Camaro database? Did GM write it? No. Also I have looked in the repair manual, and it doesnt show 2 different cams for the specifications, only one.

[This message has been edited by madmax (edited February 15, 2001).]

Kevin91Z

iTrader: (1)

The G92 305 5-speed tach has yellow at 5000 and red at 5500. I know because I have one.

Was this verified? I thought madmax didnt know what kinda car his engine came out of, just that it was a 91 Firebird with 305 TPI.

I think you're generalizing here, because my 305 has the 145 MPH speedo and 5000/5500 tach.

Guest

I give up... everyone always has the correct answers except those that find otherwise. I am never again posting information refuting anyones "proof", its pointless.

L98ina25thZ28

Kevin91Z, that is interesting. I thought that only B2L's had the 145 mph speedo, not sure why though. I didn't mean to generalize if that is what I did. Maybe the L98's and 305-230 horse cars had the 145 speedo then? Your tach may mean something then because it would have the right rpm limits for the L98 cam. Were there many G92 305's made? I pesonally only drove one G92 305 and it was a '92 1LE but that was so long ago I can't remember what speedo it had.

My 92 GM service manual lists the L98 and LB9 as having the same cams but then someone previously said that possibly all 92 305's are 230 horse engines so that could be why. I don't have any literature other than a Chiltons manual for a '91 to check on. Does anyone have a '91 GM (Camaro) service manual? It lists the cam profiles in section 6A at the end.

On another note, the 3.1's ( at least the one I saw) redlined at 6000 so they are different.

Madmax, I am not sure what I think about your and Vader's tach info but I can't see GM haphazardly making different redlines on the same engine. It sounds like your motor could be from a multitude of types of cars. Do you know the exact car it came from? Did you see it for yourself? I am sorry that you too are upset with me and anyone else who may not immediatly believe you. Would you believe me if I told you the same story knowing me or my cars history?

Some people are really touchy on this site. I had the same experience with my last post. People jump in by the thousands to repeat info that is taken for gospel but when I ask for documentation (GM paperwork, not Joe's sister' boyfriend's dead uncle said so) very few if any can show it. Usually the gospel stuff is right, but wouldn't it be easier next time someone asks a similar question to give them a referenced quote and avoid this whole dilemma? Call me a jerk, call me stupid, call me whatever you want (I am sure you have come up with some good one's already!) but I am just making people think.

Reed

Alright..SORRY guys, I'm gonna make this more confusing and probably tick some people off, but here it goes. If the exhaust is the only difference in having a more powerful 230 hp 305, why do the horsepower's change sooooo much in 88 and 89? I mean are there that many alterations in the exhaust. I don't know how factual these numbers are but lets see how close I am.

1988
305TPI: A4 195hp
M5 220hp

1989
305TPI: A4 195hp
M5 220hp (nonG92)
M5 230hp (G92)

Ok, I'm probably just throwin more fuel to the fire, but if there was no difference in the cams, how do you explain the hp jumps? especially in 89 (195,220,230) the 305 230hp must of had somethin else besides just the exhaust(ie: L98 cam). I'm no expert, if I'm wrong please disregard it. I'm just as confused here as anyone, I have a 305G92 and have always wondered what the difference between the 3 305 offered that year. I had some idea, but now its goin into a tailspin. Somebody set it straight.

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1989 Iroc-Z. 305TPI 5spd, G92 (230hp/300ft/lbs). 91-92Z28 groundeffects. Corvette Admiral Blue Metallic paint. Thermomaster chip, 160*stat & fan switch, Bosch +4 plugs, MAF screens removed, custom ram air, Flowmaster cat back, K&N, adj. fuel pres. reg.
72,000 miles. SWEET!!

89RagTopRS

The cam is the same on both 220hp and 230hp versions. Its

They also use this for the 350 w/automatic as well.

The 305 w/automatic has a different cam than the manual. This is part no. 10088155. It also has the same exhaust as the 220hp version.
The 305 w/manual and 220hp has more restrictive exhaust than the 230hp version.

MrJ your absolutely correct. I thought you needed some backup


------------------
1989 Camaro Convertible
dark silver w/black top
305tbi, auto, all stock
posi
Check out Phil's Rice Boy Page

Kevin91Z

iTrader: (1)

88 305 5-speed cars are all single cats rated at 220 HP. G92 means you got the 3.45 9-bolt rear end with disc brakes instead of the 3.08 10-bolt rear end with drum brakes. In 89, all 305 5-speed cars have G92 (I think) with dual cats, which accounts for the 10 HP gain. 89 350 cars can have either single cats or dual cats, rated at 230 HP and 240 HP, respectively. The dual cat cars will have 3.27 9-bolt disc brake rear ends, while the single cat cars have 2.77 disc brake rear ends.

What is now accepted as fact, but this hasnt been proven, is 87-89 305 TPI automatic cars have the peanut cam. And what we've recently discussed in the last month around here, is whether the 90-92 305 automatic and 305 5-speed single cat cars have the 350 cam that the 305 5-speed dual cat cars have. Based on GM manuals, and a couple 1/4 mile and dyno tests, it looks like the 90-92 TPI cars all have the same cam, the 350 cam. However, this week on the f-body.org thirdgen list, a 91 305 TPI automatic Z28 with 180k miles or so, only dynoed at 165 HP and 260 TQ at the wheels. Either that engine is tired, or it has a peanut cam.

Jason E

MrJ,

Assuming you are correct (and I do agree with your argument), what would be necessary to change to achieve 230hp on the one I'm looking at? Cat-back, dual cats and new y-pipe, right? Sorry, just a little lost after reading all that...

MrJ

89RagtopRS.... thanx for the backup, but you lost me. I was aruging that 90-92 305 TPIs have the same cam. The GM factory service manual lists one 305 TPI cam for these years.
All non G92 305 TPIs have the same small exhaust. Presumably, the 305 TPI G92s have the 350 TPI exhaust.

Kevin, I saw that post on 3rdgen.org. I was rather puzzled by it... I think the bottom line is that the car is a tired, compressionless, 191k mile POS that has seen better days. And yeah those numbers sound like those of a peanut cammed car, and most likely that car would run a high 15 second quarter.


Jason...

I think you could achieve more than 230hp with full exhaust. The manifolds are small too, so those will have to go. I think with headers/y-pipe, a single high flow cat, and a catback, you could make 240+hp.

89RagTopRS

Hey MrJ, if I said you are correct, why would I post something else that would just repeat what you already said? Kinda sux reading the same thing over and over again, doesn't it?

Reed wanted to know the difference in 1988-1989 so I gave him the info I had on those years. The cam in the 195hp and the 220/230 is different those years, but from what I've seen, its the same in 90-92.

MrJ

alright man... no problem. Just a little misunderstanding. Thanx for the backup.

86NiteRider

iTrader: (10)

WOW, NOW I AM REALLY CONFUSED BUT MAYBE SOMEONE CAN HELP ME.
I HAVE A LG4 WITH RT400 4 SPEED. 1986 SPORTS COUPE WITH T-TOPS. NO TACH AND MY SPEEDO ONLY GOES TO 90MPH. NOW I HAVE BEEN WELL OVER 100MPH SEVERAL TIMES. I AM GOING TO INSTALL THE (3)PILLAR GUAGES WITH A TACH. I PLAN TO GET A SUN TACH. WHERE SHOULD IT RED & YELLOW LINE.
ALSO I AM AT THE SAME TIME ADDING A FLOWMASTER 80 SERIES. MY CAT WORKS FINE BUT IT SEEMS YOU GUYS ARE SAYING INSTALL A NEW CAT(WHICH ONE?) AND LARGER PIPES WITH HEADERS FOR MORE POWER. AT THIS POINT I ONLY NEED THE MUFFLER AND EXHAUST BUT LIKE EVERYONE ELSE I WANT MORE POWER. MY CAR IS NOT SLOW. I HAVE WORN OUT MANY 5.O MUSTANGS AND SOME CAMARO/FIREBIRDS ALSO. MAYBE IT WAS MODIFIED BEFORE I GOT IT BECAUSE I BELIEVE I AM AT ABOUT 200 HP, NOT 175.
WHAT SHOULD I DO? BUY WHAT I DON'T NEED OR MODIFY THE NECESSITY'S. ALSO QUIT SLAMMING EACH OTHERS OPINIONS. THIS IS AN INFORMATIVE BOARD. SHARE NOT SLAM!!
THANKS FOR YOUR HELP.

http://angelfire.com/sports/niterider/86camaro.html

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86 Camaro Black SS Coupe, T Tops, Flowmaster, Custom Paint, Dunlop Road Kings S/R tires, Wheel Country Directional Chrome Wheels, New Leather seats, new carpet and headliner, complete front end suspension rebuild, new Valve seals, and more mods to come

Drew

iTrader: (58)

86NiteRider: This is a history and restoration board, you're talking about modifying a car. Try the tech board and someone might be able to help you out.

------------------
Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6Sold
92 S10FOR SALE!
98 Grand Am GT

Guest

Its because of all the misstated evidence, the experts, and everything else. Like I said before, I am done arguing. Everyone is an expert except those who question it or have proof otherwise in some form.
To clarify:

I have an 86 Trans Am. It is equipped with the 305TPI engine, one piece rear main seal... bastard block, only cast for ONE year. I pulled the stock cam out of it when I bought it, no surprise... peanut cam. Vader has an 86 Trans Am as well. It also has a TPI. Before you say something silly, you couldnt get a stick with TPI in 1986. For a reason unrelated to the engine, my tach is different than Vader's. Pretty sure he bought his car new. I bought mine from the second owner. The gauges have not been tampered with. The date code on the gauges and tach matches everything else in the car, including the build date off the build sheet. The RPO's match the VIN. This car is NOT modified or has not been modified concerning the tach. Id take my dash apart and take pictures of the date codes and my build sheet and VIN, etc. but its a waste of time with all the experts in the world that are too busy quoting "proof" when they havent seen a damn thing with their own two eyes.

91 engine. Came out of a non-G92 Camaro, 5-speed. Owner said the engine was never torn down. That explains the GM factory sealer on all the parts. Everyone said its supposed to be a peanut cam. My micrometer and degree wheel say otherwise.

Believe what you want to. If you want to believe a book, then you are a fool. If you want to believe something you have actually seen with your own two eyes, you arent. I know the truth. Whether or not you wish to accept it is up to you.

Heres a story for you:

In 1997 POCI (Pontiac Oakland Club International) Smoke Signals magazine published an article stating that there were never any 421 Tri-power cars with AC and a 4-speed. My dad disagreed. He called and said he knows of 2 people that own/ed cars just like that. The stupid writer said it was impossible, GM never built one. Angry, my dad proceeded to call his cousin, and another member of POCI who had been racing his 421 Tri-power AC 4-speed car since 1963. Both of them had build sheets and window stickers. My dad proceeded to send copies of such evidence to POCI. The POCI member who still has the 63 is a tech writer for the magazine and is well known. Stupid writer gets such copies, and refuses to change his stance, saying he wouldnt accept it unless he saw the originals, stating that they had to have been modified.

2 years ago on this board I told numerous people they made 350 verts in 1989, more specifically GTA's. Everyone said no. Well... now people know what I knew in 1989, there are 350 verts.

Not arguing, presenting facts. Its up to you to accept it, or to be silly and think otherwise. I wont be providing any more proof or evidence in reference to this subject, because there is no amount of proof that will satisfy the experts around here from what I see. I happen to know that GM was inconsistent in its manufacturing. To think that a business that produces millions of cars each year is perfect, never makes exceptions, and never makes mistakes is ludicrous.

Good day.

L98ina25thZ28

Madmax himself has said that GM has inconsistancies (sp?). The build date on his and Vader's cars may show that the one with the 5000/5500 tach is an 86 model actually built in 85 or an 86 built right before 87. GM could have had surplus engine stock from 85 models and used them in 86. That could be why the tachs are different. Can you really see the engineers in 86 saying to themselves, "We have one car, one engine... lets build two different tach's!"

Due to warranty reasons, if thereis anything GM would want to do right, it is give the consumers the right operating range for their engine.

Just some food for thought, Macewen (sp?) from the group purchase lists different part numbers for the white faced gauges for 91 G92 and non G92 305's.

MrJ

Of course there are two part numbers, because the G92 car has the 140 speedometer and 5000/5500 tach, and the other car doesn't.

Madmax already stated that he found the peanut cam in his 86 engine. If it were left over 85 stock, it would have had the better cam. But I have yet to see an 86 car run anything near a decent 1/4 mile time without a cam swap (low 16s stock), so I don't think they used any of the engines from 85 in 86 cars.

Guest

I just dont know what to say... you have no clue at all. My car was produced in Nov. 1985, Vaders in July 86. They both have the same cam. The leftover 85 blocks were two piece rear main blocks... mine wasnt a 2 piece rear main.

Keep pulling at straws... and dry the wet spot behind your ears.

Kevin91Z

iTrader: (1)

Nov 85 to July 86 is a big difference. GM probably changed the tach design mid-year. What tach do the 87 cars have?

Drew

iTrader: (58)

So what happens when everyone comes to an agreement? Other than hell freezing over?

------------------
Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6Sold
92 S10FOR SALE!
98 Grand Am GT

86NiteRider

iTrader: (10)

DREW, I KNOW WHAT KIND OF BOARD THIS IS. DID YOU EVEN READ MY POST OR ARE YOU SO BUSY ARGUING WITH THAT OTHER GUY. I AM ASKING IF I CAN MAKE THOSE CHANGES WITH THE TYPE OF CAR I HAVE BECAUSE OF THE YEAR IT IS AND THE STATEMENT YOU MADE CONCERNING THAT YEAR CAR AND ENGINE. I NOW SEE WHY THESE GUYS ARE JUMPING ALL OVER YOU. I MODERATE ANOTHER BOARD OF A DIFFERENT SUBJECT SO I KNOW HOW IT FEELS TO BE JUMPED ON, BUT YOU SEEM SO SENSATIVE. EASE UP BABY. REMEMBER YOUR STATEMENT SPARKED MY QUESTION. IF YOU TWO NEED A PRIVATE POST USE THE EMAIL SYSTEM. NO OFFENSE I JUST WANT TO MAKE MY CAR FASTER WITHOUT LOSING THE HISTORICAL VALUE. CAN YOU HELP?

http://angelfire.com/sport/niterider/86camaro.html

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86 Camaro Black SS Coupe, T Tops, Flowmaster, Custom Paint, Dunlop Road Kings S/R tires, Wheel Country Directional Chrome Wheels, New Leather seats, new carpet and headliner, complete front end suspension rebuild, new Valve seals, and more mods to come

MrJ

The reason Drew responded the way he did is because your post has nothing to do with the topic.

Drew

iTrader: (58)

You're talking about modifying a car on a board dedicated to history and restoration. How are you researching history or restoring your car by asking what tach you should use after you modify your car? Its off topic and completely off from the purpose of this board. I've let a lot of stuff slide lately cause I've been too lazy to deal with it. Don't get upset when I do whats best for the board, its my responsibility.

ps, third key up from the bottom on the left side of your keyboard. Shift is your friend.

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Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6Sold
92 S10FOR SALE!
98 Grand Am GT

[This message has been edited by Drew (edited February 16, 2001).]

L98ina25thZ28

Alright folks, I called the dealer this afternoon and verified from the parts counter that 91 Z's all had the good cam. You were all right. I am still not convinced on the tach situation though.

What I want to know then is did all Z's in 91 have the 5000/5500 tach regardless of speedo mph? Is it true that all 305 G92's recieved the 145 mph speedo in 91? Kevin91Z's car has it, do others? It is not really important but I a curious.

Mikos_89

[QUOTE]Originally posted by MrJ:
[B]WRONG.
Did you copy that off of some website? The cam is the same. Why are you trying to mislead people? The HP difference is entirely due to the exhaust.
[ENDQUOTE]

Did I copy that off a website? Nope. I conducted my OWN research on the matter. Why are YOU trying to mislead people? The cam is NOT the same. The 205hp 305 TPI auto/non-G92 had the "peanut cam" or a version of it while the G92 5sp 305 TPI had the "better" B2L/L98 cam. The horsepower difference is NOT soley due to the exhaust being different. The increase is due to the CAM, EXHAUST and to a minor extent the "revised" EPROM.

Okay, here we go again. Back in '86, TPI 305 autos lost over 25hp due to the fact that GM change the CAM over to the LG4/LO3 unit. Not exhaust. The CAM remained the same LG4/LO3 unit unless you specified the G92 package. The G92 N10 exhaust system gave you 10hp over single-cat cars depending on application beginning in the 1989 model year. In 1991, RPO N10 became STANDARD on G92 equipped LB9s and B2L/L98s.

[QUOTE]
I don't know what you are talking about with this 'primary pipe' stuff. I'll work my way from the engine back
[ENDQUOTE]

The primary exhaust pipe is the MAIN pipe extending from the cat converters back to the "inlet" section back at the muffler. You know, the BIG pipe after the converters but before the muffler. However, you probably knew what I meant anyway. Right?

[QUOTE]The exhaust manifolds are small, TBI manifolds. The y-pipe is a tiny, 2" TBI y-pipe. The converter is a 2 1/4" TBI unit. The stock catback is 2 1/4" as well.
[ENDQUOTE]

WRONG. There is NO DIFFERENCE between the (LB9) 305TPI and the (LO3) 305TBI exhaust manifolds. They are EXACTLY the same. The Y-pipe on single-cat 205hp LB9s was 2 1/4" not 2". The cat converter was 2 1/4", but it was a "high flow" unit similar to the G92 LB9s and B2L/L98s. The "primary" pipe, or cat-back pipe, was 2 1/4" in diameter while the two rear pipes coming out of the muffler were 2" in diameter.

[QUOTE]305 TPIs autos have 2.73s. 305 TPI 5 speeds have either 3.08s or 3.42s, depending on whether or not it is a G92 car.
[ENDQUOTE]

Correct. The G92 5sp TPI, for '90-'92, had 3.42s not 3.45s. Last year for the 3.45s was 1989. The last year for the BW (HD) rear end.

[QUOTE]I've toyed with BINs from both 305 TPI auto and 305 TPI 5 speed cars (90-92 of course). The difference in programming is in the spark curve, the manual's is more agressive. Other than that, that's it, besides the obvious stuff like no TCC info for the 5 speed car.
[ENDQUOTE]

Dude, what's your problem here? The spark curve timing is STILL a change between the two applications, if that's all there is. Right? That's why I mentioned that the .BINs (EPROM) for the G92/non-G92 may differ in some respect.

[QUOTE]Seriously, I don't know why people get off on misleading people like this. Please do your homework next time.
[ENDQUOTE]

Get off? HA HA HA HA.... I think the real "issue" here is how some people GET OFF in trying to "insult" people who they disagree with. I DID my homework. In fact, I DID my homework with the REAL deal. A 1991 Z28 with a 305 TPI auto. That car DID NOT have no G92/L98 cam profile in it. Wish it did though. It'd be A LOT faster. BTW, it was completely 100% original and unmodified.

It's funny how some people think that just a small change in a factory exhaust system will net them over 25hp. We're comparing two rather similar, but restrictive exhaust systems at that too. Until you start changing the exhaust manifolds to headers, you ain't gonna see no 25hp increase with just a second cat and slightly larger cat-back PRIMARY pipe in a factory-like setup. Sorry, it just ain't gonna happen until you change the CAM too.

Have a nice day!








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'89 GTA: blk on blk with 5.7 liter, T-tops, leather, N10 dual exh with 76,500 original miles. 100% stock including the ZR50 Goodyear "gatorback" tires.

Drew

iTrader: (58)

Ok, coming to this thread is like stepping into a crossfire. Nothings coming from it. I'm going to let it run till monday then I'm locking it, so get your last words in soon folks.

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Drew
The lone Thirdgenner of the Apocalypse
predatorman@hotmail.com
My Website
87 Iroc
91 Formula 14.3@98mph
91 RS Convertible
91 Firebird V6Sold
92 S10FOR SALE!
98 Grand Am GT

Jason M 91Z

My car is the same as MrJ's car, only on the Chevy platform. Since we were both impressed with how our cars ran with relatively cheap mods, we came to the conclusion that our 91 LB9/auto cars have the same cam as the LB9/G92/N10 cars. I'm a firm believer in this, although I haven't done as much research as James has.

Also, G92 DOES NOT mean dual cats, or different cam, or anything engine related. G92 means Performance axle ratio (3.23 for autos, 3.42 for manuals) and also included the G80 limited slip differential. N10 is the dual cat RPO. In my eyes, N10 also means larger y-pipe and catback. My car came with a 2 1/4" catback, and the tiny TBI cat and y-pipe. When I ditched that POS exhaust for SLP 1 5/8" headers, a 3" HF cat, 3" Edelbrock catback and Richmond 3.23's with a Torsen diff, I was all over 87-89 L98 cars.

My car came with the 4500/5000 tach. As James stated, I believe this is more exhaust related than cam related. And, there were many LB9/auto cars shipped WITHOUT the Z rated tire option, which limited vehicle speed to 113 MPH. There were two clusters offered, a 4500/5000 with 110, and a 5000/5500 with 140. Why would GM put a 140 speedo in a car without Z rated tires that had a 113 speed limiter? Hence, the 110 speedo and 4500/5000 tach in the LB9 cars, since Z rated tires weren't standard on them, as they were on the L98s. Hope to shed some light on the discussion.

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-Jason M. 1991 Camaro Z28

MrJ

Mikos_89... it's all over, you've lost. You came into this thread like you were educating us... as though we were misinformed, and you had the answers. You've been proven wrong. That's all I have to say.


L98ina25thZ28.. think of it this way

305 TPI G92 = 5000/5500 tach, 140 speedometer.

Period.

L98ina25thZ28

That is a good point, vehicles with Z rated tires should have a higher speedo. Were Z rated tires available any ony Z's or just G92's? They were req'd on L98's, right?

From my conclusions, here is what I can gather. Please correct me if anything is wrong.

All 305's were standard with 110 speedo and 4500/5000 tach.

305's, when upgraded to the G92, got the better exhaust and therefor got the 5000/5500 tach b/c of better breathing capabilities.

305's equipped with Z rated tires got the 145 speedo.

305 w/o G92 and with Z rated tires got ????????

All 350's had good cam/exhaust/tires and rec'd the 5000-5500 tach and 145 speedo.

I believe G92 required Z rated tires and therefor mandated that all G92 car got the 145 speedo and the 5000/5500 tach. The only car that I haven't heard commented on yet (I think) is a 305-non G92 car. I know Madmax (or is it Iratemax now!) said his engine came from one but I am wondering about the tach/speedo setup.

Jason M 91Z

My car is an LB9/Auto, no G92, with Z rated tires, and has the 4500/5000 110 cluster, even though I don't have a speed limiter. The only LB9 cars to get the 5000/5500 140 were G92 5 speeds.

It makes sense. You're GM, you have 5 different engine options (3.1 SFI, 5.0 TBI, 5.0 TPI, 5.0 TPI w/G92 & N10 RPO's, and 5.7 TPI), and you have two clusters. Since the majority of Z rated tire cars were 5.0 G92/N10 5 speeds and 5.7 N10 cars, you put the 5000/5500 140 cluster on them. Since the 305 auto cars didn't have a G92 option, and the 305 5 speed non G92 cars only had 3.08's, they didn't think you'd be revving high or going above 110, so there was no need to add another variable at the assembly line.

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-Jason M. 1991 Camaro Z28

[This message has been edited by Jason M 91Z (edited February 17, 2001).]

Jason M 91Z

BTW, G92 wasn't available on 90-92 Z28 autos, only 5 speeds.

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-Jason M. 1991 Camaro Z28