whiteroc

Do you know what famed engine builder John Lingenfelter says about TPI? It isn't very flattering, but then again, truth seldom is.

"Since a multi-point EFI manifold is a dry-flow design because it transports no wet fuel, it gives the intake manifold designer much more freedom. The original TPI intake manifold took advantage of this design freedom to increase runner length to create mid-range torque. An interesting aside to this story is that there is no difference in size between the 305 and the 350 TPI factory manifolds. This is because the TPI was originally designed to increase the 305's torque, since misguided planners at design time had dropped the 350 from future Chevrolet plans! Thankfully, Chevy discovered that performance wasn't dead and quickly rushed the 350 back into the production plans. Unfortunately, Chevy was forced to use the 305 TPI manifold since no other performance intake existed. This explains why the stock 350 TPI engine tends to give up at around 4800 rpm as opposed to a higher rpm point, because the intake was originally sized for an engine 45 cubic inches smaller!"

"This long runner length creates tremendous torque in the streetable rpm range between 2000 and 4000rpm. The disadvantage is, as we've mentioned, the small, long runners are not conducive to high rpm power. Bolted to a 350, the stock manifold gives up way too early. Bolting a stock TPI intake to a larger 383 motor is like bolting on a 283 two-barrel intake and carb, giving new meaning to the term "induction limited."" -John Lingenfelter

If anyone knows about TPI, it's John Lingenfelter. TPI sucked so bad in factory form, Lingenfelter had to reinvent the entire TPI setup (read "Super Ram").

Guest

Was there supposed to be some new information here or something?

92RSB4C

Like he said, TPI's made for great torque. Usually, the TPI system is only used on the street so this works great. How many cars at the drag strip have you seen use a fuel injection set-up? Not many. That's because carbs are easier and lighter(compared to intake, ECM, wiring harness, sensors, ect.) A carb is probably more responsive, since it's very direct.

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BOMB BIN LADEN I see dead Afghans in dead Fords on the side of the desert path.

airdeano

hummm lets see...
camaro gvw 3600-3800 pounds.
you need to move 1.5 tons, quickly... get
better mileage
than 12-14mpg. be conscience of 250hp (insurance
rate) have a seat-o-pants throttle response.
run a lot better than the fuel sucking carb
engines.
tpi isnt and hasnt been the high horsepower
that most people want it to be. this is not
late breaking news. weve known this since 1984.
we can make it tolerable, but 500hp TPI normally
aspirated and no NOS, isnt going to be cheap.
street rodders like the TPI because of design,
appeal, and it fills the engine compartment.
but life over a carburetor is alot better.
better?
consistancy.!
why did engine life increase after fuel injection?
carb engines usually lasted 50-80k miles.
before the villianous oil smoke...
now 100k miles isnt nothing.
but one thing mr john didnt mention is....
he has made a buck or two on his version of
TPI. and it is so terrible to run a tune port
on large CID engines.
sorry for the 'vent'

whiteroc

It was intended for thirdgeners that havent been around the block 4552 times.

You should know better than most that there are still quite a few new members that didnt know that the TPI system was only designed for the 305.

...BTW, has there been any NEW information about the TPI since 1999? I didnt think so. 99% of what gets said at TGO is for the benefit of newcomers -not veterans.

[This message has been edited by whiteroc (edited October 04, 2001).]

BadSS

Surely he would not be saying that just to get you to buy his super ram intake - NO WAY!!! LOL I don't think anyone disputes the intake system has it's limitations or would totally dispute what he's saying, but if you think he's not advertising,, you need to wake up.

Tas

Very good summery.

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-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz



Got Beach?

avro206

People must rememeber that performance wasn't a nuber one priority when they designed TPI- fuel economy and emssions were just as big concerns.

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88 TBI IROC- mods- 5500 rpm redline tach, 240 KM/H speedo,
L69 air cleaner installed! Yeh my Gf's Grand Am GT is still faster

L98IROCZ89

Uhm... it gives up at 4800 in the 305 also. Stock TPI is stock TPI is stock TPI, regardless of the displacement of the motor it is bolted to.

TPI promotes a large amount of low end torque. As a result, the tradeoff is loss of high RPM power. Everyone knows this, but when few people don't know is that in stock form, TPI/3rd Gen Fbodies are NOT drag racing vehicles. They are designed to take a hard turn(i.e. low RPM) and the torque it up following the turn.

In closing, TPI is good for what it was MEANT to do.

(Side Note: This is not to say TPI cannot be modified to work well in a drag car and promote high end HP - I am speaking of stock TPI and its intentions.)

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1989 Chevrolet Camaro IROC-Z
L98 - 350c.i. TPI, rebuilt 700R4 auto w/shift kit, Dual catalyst Monza PaceSetter Cat-Back, SLP 1 5/8 Coated Headers, 3.23 Posi rear, Hypertech chip with 160stat, MSD 6A, Under-Drive pulleys, AFPR, K&N's, !Air Box w/ Ram Air, moddified MAF, !TB Coolant, Spohn Dual Cat SubFrame Connectors, Alarm, Keyless entry, remote starter, 92 Z28 AeroWing, Brand New Paint (6/21/01)

Future: ZZ4 TPI w/EGR, T56, 3.42 or 3.73, Spohn strut tower brace and LCA's, Accell 24# injectors

1989 Chevrolet Celebrity Eurosport <--DEAD AS OF 9/20/01
2.8 MPFI, no mods
225,000 miles and still ticking!

More info and pics on my webpage:http://go.to/iroc-z

AOL IMer: GPA 0point0

Abubaca

iTrader: (3)

First off- I love my TPI 350 set-up.
Second- how many of us use good old disposable air filters? Does that mean they suck? I think it's safe to say that unless you're showing a completely stock all original 3rd gen, most of us here are NOT running stock TPI's,or at least don't plan to for very long.
- and if nothing else...Dear *** it is a beautiful looking motor!!!

Abubaca

iTrader: (3)

They bleaped the name of our lord? oops, Sorry. ???

91'firebrd

If TPI is so bad then why did GM go back to a tuned port setup in the LS-1 even after they did a decent job (public acceptance) with the free flowing LT1??

How often do you need to run your engine at 6000 rpm? I run with a 3500 rpm limiter and rarely hit it.

Even if the intake manifold is ported out or replaced with an aftermarket unit to handle the cfm needed to run high rpm, the stock cam is not setup to make power upstairs.

Easy enough you have the intake setup to supply more air and put in a bigger cam to make power upstairs. Now you have a problem with the heads not flowing enough. So you port or replace the heads to match up with your cam and now you fail emmissions.
And I'd bet you would fail the idle test.
For those living in states not checking emmissions, consider yourself lucky.

I think when you look at the whole picture as far as what is needed in a STREET car a TPI system is unbeatable.

okfoz

I like my TPI conversion, it was well worth every penny & ounce of effort. Granted, I think it could be faster, higher RPM etc, but I get much past 5K and I get nervous about breaking things anyway.

What I like about my TPI:
1) it looks really Kewl
2) I went from 15-17 mpg to 23 mpg
3) I can program my own chips now
4) since I converted my car I know lots more about it
5) It has GREAT drivability charactistics
6) I get to join this Forum where these really kewl people can answer a bunch of questions that I have.
7) learning about FI is a fun thing.

What I dislike about my TPI
1) a little more expensive to fix than a carb
2) Cleaning under those runners looks like a real PITA
3) it is not as simple as a carb


I think I will stick with TPI

John

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G O D BLESS AMERICA
87 Formula Yellow/Black

5.1 TPI Automatic
Baer 12" brakes 4 wheels, KYB AGX Adjustable Shocks & struts, Custom Leather interior, WAAAY TOO MANY MODS TO LIST

87 Formula TPI (5 Speed) Yellow/Gray STOCK

1967 Buick Riviera 430hp Turns high 14's (Not bad for 4300 lbs)

83 Camaro (Parts)
83 T/A (parts)

http://www.3rdgenformula.com

Crusader

iTrader: (1)

Just curious but do you ever plan on doing any racing with that low of a limiter? I love my TPI and my goal is to build a 400 small block with a TPI system (most likely a Super Ram) and having a shift point/red line of ~6000-6300

Jess

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1988 GTA - 5.0 Auto now with 5-speed power!
1989 Firebird - 2.8 5-speed: Sold

My Page - http://transam.freeservers.com
Firebird owners check out http://transamgta.com

Abubaca

iTrader: (3)

A guy in our club just ran 12.28 ET this weekend at Rockingham. 383- LPE cam- AFR 190 heads- headers/dual exhaust-t56 with 3.73 gears....and a LPE long tube TPI. Not sure of all the exact specs, but he said even though he could make it faster, he loved the look of the runners/TPI!!!

PETE

iTrader: (1)

i'd like to see that article!for one lingenfelter didn't start out as the almighty hp guru he is.as i recall his career started with GM as an emissions equipment designer.and for him to bash the tpi setup is rediculous he designed the engine that went into the fastest american made tuner car too date.does anyonne remember the joint venture with calloway cars in 89(vette).it ran 10's all day long had a top speed of 254.76mph and idled at 700 rpm's.now i know what most guys will say who has the money to put twin turbos on this engne etc,not many but it just goes to show that the tpi can be made to run with the best of them.you have to remember that when the tpi unit is under boost the flow limits of the intake get thrown out the window(to an extent).now you tell me if lingenfelter can use a standard bore,production 350, blueprint it, fill it with forged internals and wring out 880hp using a tpi unit it cant be all that bad.you cant compare a tpi car to newer technology it will always lose.one more thing do you ever think that you're gonna find an ls1 4th gen in ten years or so with 100,000 miles for a decent price like you can for a 3rd gen,i think not.

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87 trans am,gm crate 350(4 bolt mains 10to1),L98 aluminum heads,LT4 hot cam,slp runners,slp 1 5/8 headers,3in.y-pipe,edelbrock base,hi flo cat,air foil,afpr,as&m ported plenum,gutted airbox,t-5 tranny w/centerforce clutch and a 3.27 9bolt(11.9in. brakes),ed wright's fastchip,relocated iat sensor,160 fan switch&t-stat,tb bypass,accel supercoil,cap& rotor,slp 3in. catbcak,a/c delete.

SHE IS GONE BUT I KNOW THE GUY WILL GIVE HER A GOOD HOME.

best e/t:
3653lbs./full tank+ driver.
14.10@96.53mph 2.01 60'

mystikkal_69

iTrader: (2)

I thought that was the purpose of the TPI induction or any fuel induction system. TO SUCK ................
hehe

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86',88',89' IROC-Z, 350 TPI, 700-R4

94' Formula, LT1, 6spd

S10Wildside

I'd just like to add that TPI is awesome for the street. I've got a 355 TPI in my All Wheel Drive S-10 and it's amazing how much torque can go through these motors. Being that I don't race at the strip very often, I'm much better with lots of torque and hp in the lower RPMs. I can even break all 4 tires free if I stomp on the gas.
It's also an awesome looking setup!

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1982 S-10 Wildside
355 TPI, Accel High-Flow Intake, Ported Plenum, Arizona Speed & Marine Runners, TPIS AFPR, Edelbrock BBK 52MM Throttle Body, Sanderson Ceramic Coated Headers 1993 Typhoon Drivetrain

Dyno Don

iTrader: (7)

Excuse ME but didn't the '85 'Vette come with a "350" and TPI. Who said it was designed for the "305" anyway?

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Chronologically challenged. But still kicking!
'92 CAMARO RS
305 TBI 5/spd (now TPI)
B4C Alt.
'69 camaro-BB/Lenco,1050 dominators, /Pump Gas/no drugs 8.97-150+/3200lbs.
SoCal Thirdgen F-Bodies

[This message has been edited by Dyno Don (edited October 04, 2001).]

formul8!!

Simple fix:

Bigger runners,ported plenum,better manifold base,bigger throttle body and an airfoil if needed and you fixed the problem.

Greg '85 T/A

Hmmmm. So the fix is to throw away all the stock stuff?

BTW, that's always been the recipe for hot rodding GM cars - whether they're carbed or FI'd.

[This message has been edited by Greg '85 T/A (edited October 05, 2001).]

fly89gta

iTrader: (1)

hmmmm thats funny...my "sucky" TPI hasn't had any problems hitting the 13's, and it hasn't even been pulled, nor have the valve covers. The purpose of TPI is low end torque, not high RPM power.

And as stated before the TPI was intended for a 305. GM was actually planning on putting a 305 in the vette , morons they were for even thinking that! TPI is good for what it was designed for. But TPI goes bye bye this spring, actually so does the whole SBC, HELLO turbo 3.8

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Check out MyGTA Nicknamed:The Big Red Machine
***AOL IM ClarkeMustGoNow***
Moderator at www.transamgta.com
"What does not kill us only makes us stronger"

Tony

whiteroc

This is what I meant^ when I said TPI Sucks.
(I didnt write the article -Lingenfelter did.)
I only posted the article because I have come across quite a few people that didnt know TPI was built for the 305.

Even though is revs like a diesel, I still love my TPI. -

I wish you guys would respond to my tech questions as fast & as much as you did here.

jmd

iTrader: (4)

I prefer

"The stock TPI intake sucks"

to

"TPI Sucks"

Mainly because other than the fact that it's batch fire, it's a pretty contemporary system. Granted, the newer PCm's are faster, everything is sequential now (ooh, 5hp, whoopie) but it works, from 205hp 305's to modified mini-ram 400's.

Just gotta put the right parts on the right motor, and for a lot of motors the stock TPI intake is not the right parts.



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jmd
1986 SS with...
86LB9 TPI atop the original L69, hydraulic clutch T5, Energizer 272 cam, chargedair.com fan, Global West CNR-88-C negative roll kit, 89 Iroc front springs, CC635 Moog rear springs and a whole bunch of other fun stuff

1MeanZ

iTrader: (9)

where does it say anywere that the TPI was designed for a 305? i find it hard to believe that GM even consiedered the 305 for a vette. sounds like a bunch of BS to me. where are you guys gettin your info?

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86 IROC
43,000 miles
305/700R4/3.23 gears
maroon, gold stickers, black interior, T-Tops.

current mods.
shift kit
headers
cat back exhaust

mods planned for this winter
cam
3.73 gears
subframe connecters

88IROCs

1MeanZ,

Ya gotta keep in mind the political climate, in 1981(prolly before u were born), at the time the work on TPI started. The world was in a recession, the Arab's jacked-up the price of oil, tree-hugger's were becoming a powerful lobby and the EPA was shooting for CAFE-mandated 25 mpg fleet averages. In short, it wasn't a great time to try and sell V-8's - especially the big-cube, high-horsepower, gas-guzzling kind of V-8 Detroit was used to selling. Chrysler was going bankrupt trying to sell full-size cars, Ford's most powerful V-8 made 145 hp and GM was trying to sell 4.3 L gas V-8's and V-8's converted to run on cheaper diesel fuel. Most of GM's engineer's didn't expect the small-block to last to mid-decade(the Corvette guys were working on turbo-charged V-6's at the same time they were developing TPI). The TPI was designed for the purists who would inevitably insist it wasn't a Vette without a V-8(overlooking the fact that the Vette was originally only offered with 6 cylinders).

In light of all of the engineers' concerns at the time - economy, emissions, etc.,... - it was thought that if a V-8 had to be available, it would have to have less displacement than before. The 305 had already been in production for 3 years by 1981, and seemed like the likely mill to use for the TPI.

By 1983, gas-prices were down, the Economy was improving and there didn't seem to be enough reasons to limit the Vette to a 305. It didn't help that the 305 was developing a bit of a rep for being unreliable. It did help that even though it was originally offered with the 350 CFI motor, the Vette guys decided that the C4's had to be a big improvement over the C3's(not hard considering how bloated and weak-kneed the last C3's had become).

Thankgawd the Vette folks saw that V-8 performance was not going away, and that the 350 was the way to go(otherwise us thirdgenners wouldn't have had 350's either).

I remember around 1984, most guys were more interested in owning the more powerful Supra or 300Z(or a 944 if you were bucks-up), than any weak 305 powered f-body. It took the introduction of TPI(first in the 305 and then in the 350) to stir real interest back in our favourite cars. Without the sales success of TPI-powered cars, I wonder if Chevy would have had the nuts to develop the LT-1 and the LS-1?

92RSB4C

With 145 hp V8's, it's a wonder any V8 sold.

formul8!!

A 2000 Civic Si will run circles around a 1982 Corvette or F-body. Pretty sad....

1MeanZ

iTrader: (9)

i was born in 81 actually. i still think TPI is a good setup. as others have said it was great for what it was designed for. a lower rpm torque motor. which is what a street motor should be.

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86 IROC
43,000 miles
305/700R4/3.23 gears
maroon, gold stickers, black interior, T-Tops.

current mods.
shift kit
headers
cat back exhaust

mods planned for this winter
cam
3.73 gears
subframe connecters

Mark_ZZ3

I would hope after 18 years, some smaller engine would be faster (2000 honda vs 82 vette). Lots has happened in 18 years.

145 HP V8 was about all you could get at the time. The imports were not much better, well except at rusting .. :-)

The TPI was a engineered attempted at bring more to the V8. It was the beginnings for future V8's and showed there was still a market for them. As well, the V8 could be emission legal and get decent mileage.

I still think the TPI engines are one of the sweetest looking setups GM ever made. All the rodder like the TPI because it looks good. The LT1 and LS1 are more powerful, but they don't have the same eye candy appeal.

I am temped to give up the power potential of an LS1 just to keep the "gasp!" expressions when you open your hood to reveal the TPI.

Then again, a supercharger would fix any performance problem and keep that eye candy appeal.

Mark.

nice3rdgenz

comparing a 00 civic to a 82 vette or camaro is like comparing apples to oranges. try comparing a 82 civic to a 82 camaro or a 00 si to a 00 z28.

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91z28 350tpi auto runs 14.3

whiteroc

It is hard to believe... but its true.

Case & Point for submitting my original post.

Here is 1 of many links that tell of the TPI being solely designed for use with the 305. The TBI guys will like this site very much.

http://www.goingfaster.com/spo/praisetbi.html

RoadRocket L98

Why did they shorten the length of the LS1 runners when they built the LS6.


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'89 Firebird Formula 350
L98, WS6, Red/grey, t-tops, and a 3.27:1 rear
K&N, TB bypass, no MAF screens, CAI, full Accel ignition, no cats, Hooker Supercomp shorties, Hooker 3-inch catback
ET? 14.8 @ 93mph
Also own '83 Firebird 2.8 2bbl. 155K miles.
ET? Break out the calendar!

Crusader

iTrader: (1)

Probably for better high end breathing for the LS6's higher red line.

BC86TPI-Z51

In 81 or 82,cant rem what years, there WAS a 305 in a vette, california state and emissions only.
So theres a few running around out there.

RedHawkLB9

john....stfu will ya?

jms

iTrader: (1)

Old thread.

I'm not sure if you were directing the comment toward Lingenfelter.

If so, then see the following link:
http://www.goingfaster.com/spo/who_i...genfelter.html

If not serious, my apologies.

jms