black5.7GTA

Okay,I have posted this question elsewhere and have gotten no help.Either they dont know,dont care,havent seen it, or all of the above.Anyway,why in every listing Ive seen for the IROC its 245,and corvette 245 or 250 with sport mufflers,but according to both the Formula and GTA source and even in some books,its 235 It was my understanding that the 90-92 L98 engines with dual cats were identical and should have rateings of 240 in the Firebirds and 245(which they do,in the Camaros.The Camaro had the 5 horsepower edge from 88-89,and 90-91 due to the air intake,how is it 10 in 90?The 5 horsepower increse over 89's 225 or 235 with dualcats was due to speed density control system,camshaft revision,and lighter pistons.Why is it listed correctly for the 2 Chevys,but not the Pontiac?I am 99.9% positive I am right but this is bugging me.Any body know the scoop?

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1990 Trans Am GTA
Black/Black leather
350 auto 3.23 dual cats
SLP package
SLP torque converter
SLP shift kit
Fastchip PROM
245/50/16 GSC's

G-Tech
0-60 5.1 1/4mile 13.6@104

[This message has been edited by black5.7GTA (edited February 25, 2001).]

[This message has been edited by black5.7GTA (edited March 16, 2001).]

IROCZTWENTYGR8

iTrader: (1)

245HP@4400 345Torque@3200 from the Tech Section of this site.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

[This message has been edited by IROCZTWENTYGR8 (edited February 25, 2001).]

black5.7GTA

Oh yeah,thats not correct either,thats the rating for just the IROC.Their should be 3 ratings 1 for the IROC,(245)1 for the Trans AM,Formula,and GTA,(230)and 1 for the Trans Am,Formula,and GTA with dual cats.(240)If I am right.

[This message has been edited by black5.7GTA (edited February 25, 2001).]

[This message has been edited by black5.7GTA (edited February 25, 2001).]

IROCZTWENTYGR8

iTrader: (1)

https://www.thirdgen.org/newdesign/tech/techdb.shtml

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

black5.7GTA

Ive noticed also on their that they do not differentiate the Camaro and Firebird engines,and there should be a 5 horsepower difference for 88-92 of the same configuration(dual or single cats)and 15 in 87.Ive also noticed on their,Moter Trend and the GTA and Formula source both the 91 and 92 LB9 5spd engines with G92 have 230hp both in the Camaro and Firebird.Whats the deal with that,and shouldnt it be 225 for the Firebirds?

[This message has been edited by black5.7GTA (edited March 16, 2001).]

black5.7GTA

Boy,this is getting really according to the Tech section,the 5 horsepower increase was only in the L98 from the lighter pistons,not the combination as in the vette.The LB9 did not have those pistons,(I didnt know that)but it had SD,but the hp stayed the same as 89.(230)According to the GTA source it was 225,same as 89 then increased to 230 in 91-92.So,what made that increase?

IROCZTWENTYGR8

iTrader: (1)

OK dude, I see u really want some kind of an answer to this thing so here it goes. Yes, the IROC-Z's have a 5-10 HP and Torque advantage on the GTA's. This is because of the the better air intake that the Camaro has. When u see specs that only have 1 set of results like that, its usually for the Camaro, so u can expect to take 5-10 off of the GTA's #'s and not add 5-10 on the Camaro.The IROC-Z also has a weight advantage on the GTA. These things make the IROC-Z faster stock than the GTA. I have seen results of them both being run at the same time and place stock, and the Camaro always had the faster times.

The power increase in 89-92 Third Gens is because of the use of dual converters and different cams. Even in 90-92, Speed Density has nothing to do with making them faster, its those things I just mentioned.

Thanks 91Z, I knew that, just a typo.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.



[This message has been edited by IROCZTWENTYGR8 (edited February 28, 2001).]

Drew

iTrader: (58)

Those numbers are just factory guesstimates for advertising. They don't account for drivetrain parasitic losses, they don't account for fitment and blueprinting, etc... When GM assembled the typical L98 you could probably see 5hp difference in one vs another just due to production tolerances. Besides that the Camaro air ducting necks down close to the same area as the firebird ducting. GM's numbers don't make much sense, they show the same hp figures for dual cat cars as single cat cars, yet they state in the promotional literature that the dual cats are good for another %12-15 of horse power... According to my calculator that'd be a lot more than the bare hp numbers indicate. Right off I'd say that the differences between the Camaro and the Firebird in the poewr department are so slim that you aren't going to see any difference on the street or the track... Throw them on the dyno and they'll probably still confuse the hell out of you by running even...

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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

black5.7GTA

IROC,and Drew,I appreciate the help but their is nothing you guys have said that I dont know.My original question was what is the correct FACTORY horsepower rating for the 1990 B2L GTA,TA,and Formula,235 or 240?and why is the listing 240 in 91 and 92 and not 90,not which of the 2 (Iroc or GTA is faster stock)or not "actual" horsepower and production tolerances and variances.Anybody?

Mark 89Formula

Black5.7GTA, you are correct. 240 HP was the factory's rating for the 90 B2L in the Firebird with dual cats, same as 91 and 92. I have no idea why the various databases have the wrong information.

Kevin91Z

iTrader: (1)

I have to correct you and say dual cats started in 89, not 88.

black5.7GTA

]

Okay,Ill state that the correct factory ratings of the 1990 L98 engine in the Firebirds are
240hp@4400 and 340FT/LB@3200(N10)
230hp@4400 and 335FT/LB@3200 and the others are wrong.Now,just for curiosity,Why is their a power increase from 225 in 89 and 90 to 230 in 91 and 92 in the LB9 Firebird?Like I said,I have an old issue of MoterTrend that has both the 91 Firebird and Z28 (G92)listed as 230.It also sas 230 on both the Formula and GTA source.Why are they equal in that(and 92)year,but the Camaro has the 5hp edge from 88-90?



[This message has been edited by black5.7GTA (edited February 26, 2001).]

Drew

iTrader: (58)

The factory figures for power for the L98 vary from one pontiac document to another. You say 230, but yet I've got an official pontiac press release dated December 26, 1989 that shows 235hp...

Don't try to find an explaination for every piece of conflicting information, because its not always clearcut.

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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

black5.7GTA

There should be only one answer to this question.So what you are saying is Pontiac rated it at 235(and didnt include the 5 hp increase from the lighter pistons,like chevy did)If thats the case,I really dont know why they would rate it 240 the next year in 91,when the engines are identical.Did the person who quotes the hp rating just say"Ah,lets rate this here moter this year as 240,even though its exactly the same as last years"Is there own literature wrong?Drew,Thanks for the help,but I'm still confused,and even though my car is pushing close to 300hp now,I would just like to know this answer.

IROCZTWENTYGR8

iTrader: (1)

U are asking why the GTA is rated at 235HP and the IROC-Z is 245HP in 90, correct??

If u read my previous post, its says that every TPI engine that they put in Camaros, have a 5-10HP advantage due to the better air intake design that the Camaro has. The Tech specs on this site are the Camaro #'s, just take off 5-10HP to get the GTA's specs.

The GTA got the same engine upgrades the IROC-Z did in 90, and it gave a 5HP increase. Thats why the IROC-Z is rated at 245HP in 91 and the GTA should be around 240HP. The GTA isn't going to be the same because of the more restrictive air intake, if u want to know the actual #'s call a dealer or something. It might be better if u put #'s next to each individual question u want answered. U are asking a few different questions in every post.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.



[This message has been edited by IROCZTWENTYGR8 (edited February 26, 2001).]

black5.7GTA

1.why is horsepower for 90 L98 in Firebird 235,then 240 in 91.
2.why are both the Camaro and Firebird LB9's 230hp in 91 and 92.

BTW,IROC,in your last post you list the 90 IROC engine as 245 then say it gave a 5hp increase in 91 and "thats why the IROC-Z is rated at 245 in 91"There was no power increase in 91,it was in 90,(5hp)my whole point,and every year from 88-92 the Camaro had a 5hp edge(of the same configuration)except 87 when the difference was 15.

[This message has been edited by black5.7GTA (edited February 26, 2001).]

[This message has been edited by black5.7GTA (edited February 26, 2001).]

[This message has been edited by black5.7GTA (edited February 26, 2001).]

IROCZTWENTYGR8

iTrader: (1)

1.In 90 the L98 was rated 235HP because of the switch to dual converters. In 91 there was a 5HP increase from the GU6 option that included not only dual converters but, disc brakes, engine oil cooler, and performance axle ratio.

2.The Camaro is rated at 230HP for 91 and 92 LB9's, the Firebird is not. The Firebird is rated at 225HP in 91, which also had an increase from the GU6 Performance option, and 230HP in 92. The 5HP increase in 92 is from the R6P Performance option.

Yes, that was a typo, it was in 90.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

[This message has been edited by IROCZTWENTYGR8 (edited February 26, 2001).]

black5.7GTA

IROC,it would be easier if you go back and read the posts but

1.The switch to dual cats was in 89 not 90.In 91 their should be no increase in the Firebird with N10 like their isnt in the IROC.

2.MoterTrend,the GTA and Formula source list the 91-92 Firebird LB9 5sd as 230.

[This message has been edited by black5.7GTA (edited February 26, 2001).]

IROCZTWENTYGR8

iTrader: (1)

1. LOL, I put 90 again!! I know its in 89 I keep saying 90 though. I know much more about Camaros than Firebirds. U might want to ask these questions on a Firebird or GTA specific site.

2. Thats a magazine, the #'s I am giving u are from GM.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.



[This message has been edited by IROCZTWENTYGR8 (edited February 26, 2001).]

IROCZTWENTYGR8

iTrader: (1)

http://www.gtasourcepage.com/

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

black5.7GTA

1.I have asked this on the GTA source twice with no reply.
2.MoterTrend might be a magazine but like I said,both the GTA and Formula source and I believe the Firebird book list them as 230.Thanks anyway.

IROCZTWENTYGR8

iTrader: (1)

Hold on....

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

[This message has been edited by IROCZTWENTYGR8 (edited February 26, 2001).]

black5.7GTA

I'm here

IROCZTWENTYGR8

iTrader: (1)

E-Mail this site or get a # to call if u can, they should have alot of information on GTA's http://www.phs-online.com/

I know Camaros alot better, but I guess not many wanted to get into this, so thats all I know about GTA's.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

[This message has been edited by IROCZTWENTYGR8 (edited February 27, 2001).]

black5.7GTA

FLAMED!and still no "correct"answer

black5.7GTA

No luck,that site is for old farts and their GTO's,and wants me to pay $45 for an Info pack

Mo

I have a 90 with all those options you listed that came in GU6 (i.e. oil cooler, disks, ratio), how would they gain 5 hp in 91 by adding these if they already were on the 90's??

As for why IROCs are rated higher in some places i don't know, sorry.

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90 IROC 5.7l (L98)
ram air, K&Ns, air foil,Flows


LIKE A ROC

black5.7GTA

Mo,thats my piont,their is no difference in power between the 90 IROC(245) and 91 Z28,(245)and shouldnt be in the Firebird,but the 90 B2L Firbirds are listed as 235 while 91 240.The engines from my understanding are identical.Like I said the B2L engines from 88-89 and 91-92 are 5 horsepower more in the Camaro of the same configuration,due to the air intake but its 10 more in 90 with no explanation.

Drew

iTrader: (58)

The Firebird is listed the same for 90-92 in all my literature.

------------------
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

Mo

ya, I see what your saying, why wouldn't 90 birds be 240 like the 91-92 birds. Sorry, I don't know, I would think they'd be the same.

PONTIMANIAC 90

I'll answer your question for you. Consider this to be the end to your quest.Factory HP ratings are meaningless.
Wether it's 225 or 230 or 250.It makes no difference. It's their PR numbers.MEANINGLESS!!! If you wanna make sece of i all, forget it.
From what I read my car(read sig) is rated at 230hp.There was no difference or any significant changes for the 92-93 years. So they're all 230hp 305TPIs.Is the figure true? Who knows.
5.0 stangs had a 225hp rating in 87. They made a bunch of changes from 87-93 but they only revised the rating for 93(205hp).
Even though the stangs steadily got less HP from 87-on, they chose not to dyno the f**ker until 93.
You tell me, dude.

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1990 Formula
Factory:TPI-305/Dual Cat(230hp),5 Speed,3.42 rear, Dealer:Aluminum Drive Shaft
Mods:SLP air foil,K&N Filter, Accel:wires,coil cap,rotor.Hypertech Thermomaster chip,Stat,Fan switch,TES headers,MSD6AL,Flowmaster 3" Cat-back exhaust,TB coolant bypass, Centerforce clutch (going).

black5.7GTA

Drew,then what you are saying is the 90-92 Firebirds have 235hp,because you said you had a press release that said 235 for 90 right?How is that now?

black5.7GTA

The 93's had the 275hp 5.7LT1 but I understand what your saying,and know what happened with the mustang but atleast there was an explanation their and their isnt one here.I just wanted to know what the "correct"(meaning one)rating from the factory was and if their was a difference(although I was 99.9%positive their wasnt any).So,Ill just go by where I listed the ratings.



[This message has been edited by black5.7GTA (edited February 27, 2001).]