Was I too Optimistic ? TPI L98 Power
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Joined: Apr 2014
Posts: 194
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From: Los Angeles
Car: 1989 Formula 350
Engine: 350
Transmission: T-5
Axle/Gears: 3:23
Re: Was I too Optimistic ? TPI L98 Power
Seems that the new ACDelco O2 sensor fixed the knock count problem.
The last thing now is I really Really Really wish I had them rebuild my stock converter... The stall on this exchange / rebuild is just way too low... Belongs in a truck.
The last thing now is I really Really Really wish I had them rebuild my stock converter... The stall on this exchange / rebuild is just way too low... Belongs in a truck.
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Joined: Jul 1999
Posts: 1,556
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From: Adrian, Mi, USA
Car: 1988 Pontiac Firebird Formula
Engine: 5.7 TPI
Transmission: 700R4
Re: Was I too Optimistic ? TPI L98 Power
Time to swap it out? Have you chatted with the folks that did your trans about it??
Joined: Jul 1999
Posts: 12,089
Likes: 125
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Was I too Optimistic ? TPI L98 Power
-- Joe
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Member

Joined: Apr 2014
Posts: 194
Likes: 2
From: Los Angeles
Car: 1989 Formula 350
Engine: 350
Transmission: T-5
Axle/Gears: 3:23
Re: Was I too Optimistic ? TPI L98 Power
I'm just going to put up with it for now... I drives great but I swear the convertor is locked up at about 900 rpm. I did the motor / trans swap by myself in the driveway.... I'm still having re-occuring nightmares,,, and my hands/knuckles have just healed up.
Joined: Jul 1999
Posts: 12,089
Likes: 125
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Was I too Optimistic ? TPI L98 Power
The last transmission I did on my back, I think I was 18. I've had a lift since about 19 or 20.
-- Joe
Re: Was I too Optimistic ? TPI L98 Power
Timing Set static with brown wire disconnected at 6 degrees ADV. I'll do the cranking compression today and try to get ahold of a fuel pressure gauge.
I 've had TPI cars before, Vette's and Firebirds... This just really seems to fall short. My 91 TPI Frebird had the 3:08 gears, was bone stock and would light the tires from a stop. This one is 3:23's and pulls away from a stop like a V6 Camry.
I 've had TPI cars before, Vette's and Firebirds... This just really seems to fall short. My 91 TPI Frebird had the 3:08 gears, was bone stock and would light the tires from a stop. This one is 3:23's and pulls away from a stop like a V6 Camry.
Joined: Jan 2005
Posts: 10,406
Likes: 492
From: Hurst, Texas
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: Was I too Optimistic ? TPI L98 Power
As nice as fuel injection is . I still run carb. You cant beat it for off the line grunt and power.injection may get better milage, but who cares, were talking performance.you cant beat a carb dumping a butt load of fuel all at once to get a car moving! I have a 72 grand prix 463 cid 750 double pumper Holley . It leaves the line hard as hell. Run 12:40s all day.
Joined: Jul 1999
Posts: 12,089
Likes: 125
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Was I too Optimistic ? TPI L98 Power
As nice as fuel injection is . I still run carb. You cant beat it for off the line grunt and power.injection may get better milage, but who cares, were talking performance.you cant beat a carb dumping a butt load of fuel all at once to get a car moving! I have a 72 grand prix 463 cid 750 double pumper Holley . It leaves the line hard as hell. Run 12:40s all day.
-- Joe
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Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Was I too Optimistic ? TPI L98 Power
As nice as fuel injection is . I still run carb. You cant beat it for off the line grunt and power.injection may get better milage, but who cares, were talking performance.you cant beat a carb dumping a butt load of fuel all at once to get a car moving! I have a 72 grand prix 463 cid 750 double pumper Holley . It leaves the line hard as hell. Run 12:40s all day.
Fuel Injection Makes more Power... period.
Joined: Mar 2001
Posts: 10,405
Likes: 2,081
Car: '89 Firebird
Engine: 7.0L
Transmission: T56
Re: Was I too Optimistic ? TPI L98 Power
It is true that carburetors have excellent throttle response. My injectors max out at 60% duty cycle so I can get all the fuel in before valve closes, even at 7000 rpm. I have no trouble matching the throttle response of a carburetor.
And I have a wide-band O2 sensor with closed loop compensation during acceleration so the fueling is always spot on. Can't do that with your carburetor.
And I have a wide-band O2 sensor with closed loop compensation during acceleration so the fueling is always spot on. Can't do that with your carburetor.
Last edited by QwkTrip; Jun 7, 2018 at 12:43 AM.
Joined: Mar 2001
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Car: '89 Firebird
Engine: 7.0L
Transmission: T56
Joined: Sep 2003
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
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From: pa
Car: 87 IROC
Engine: 350
Transmission: auto
Axle/Gears: 3.23
Joined: Sep 2003
Posts: 25,895
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Was I too Optimistic ? TPI L98 Power
Speed isn't everything. If it is, there is always someone faster. Cars start to lose their fun to drive factor as it slowly gets converted over to pure straight line performance.
It's supposed to be about how it makes you feel when you drive.
It's supposed to be about how it makes you feel when you drive.
Joined: Mar 2014
Posts: 4,553
Likes: 806
From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: Was I too Optimistic ? TPI L98 Power
The faster cars I've had stayed tore up a lot. I've enjoyed cruising in my L03 for a while but I'm working on a L98 to put in next year. Got bored i guess. Hope I don't regret it later.
Joined: Mar 2014
Posts: 4,553
Likes: 806
From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: Was I too Optimistic ? TPI L98 Power
True. Just hope it's as trouble free as the lil fellow in there now.
Member
Joined: Dec 2005
Posts: 174
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From: Shelby,N.C.
Car: 1986 pontiac bonneville
Engine: LB9 305
Transmission: MK6 T5
Axle/Gears: 3.42
Re: Was I too Optimistic ? TPI L98 Power
if you want a better convertor, pick one up from a mid 90s tolower 2000 S10 with a 4.3, highest stock convertor there is .
Joined: Mar 2014
Posts: 4,553
Likes: 806
From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: Was I too Optimistic ? TPI L98 Power
Not optimistic.... You have to take advantage of critical amount of torque. Not high rpm lt1 or ls1 ...i seen a 383 with procharger and Afr heads tuned and tweaked put it right right in air facing sky. It was 9.09 at 138.he tuned the hell out of it and tpi smart.tpi scavenge effect like headers they are desinged to be Torque monsters. Keep gears low at 3.12 or 3.23 ..any higher puts you out of torque and horsepower peak. Unless t56 6 speed manual then 373 potential option depending on full application. Get back.... I'm tpi....conisore. lol
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Was I too Optimistic ? TPI L98 Power
Not optimistic.... You have to take advantage of critical amount of torque. Not high rpm lt1 or ls1 ...i seen a 383 with procharger and Afr heads tuned and tweaked put it right right in air facing sky. It was 9.09 at 138.he tuned the hell out of it and tpi smart.tpi scavenge effect like headers they are desinged to be Torque monsters. Keep gears low at 3.12 or 3.23 ..any higher puts you out of torque and horsepower peak. Unless t56 6 speed manual then 373 potential option depending on full application. Get back.... I'm tpi....conisore. lol
Joined: Sep 1999
Posts: 4,353
Likes: 308
From: NJ
Car: 92 Firebird
Engine: 4.8 LR4
Transmission: T56
Axle/Gears: 3.45 9 Bolt
Re: Was I too Optimistic ? TPI L98 Power
It sure can have some of them, and the only thing in my 3rd gen that squeaks or rattles now is the passenger seat, I spent a lot of time with the 1/8" closed cell foam in the dash, vibration damper on all the flat sheet panels and mass loaded vinyl on the firewall and full floor. Still have more to do, but it is much better than it was before. If my rear didn't howl, it would be close to luxury car on the inside for sound.
Re: Was I too Optimistic ? TPI L98 Power
It sure can have some of them, and the only thing in my 3rd gen that squeaks or rattles now is the passenger seat, I spent a lot of time with the 1/8" closed cell foam in the dash, vibration damper on all the flat sheet panels and mass loaded vinyl on the firewall and full floor. Still have more to do, but it is much better than it was before. If my rear didn't howl, it would be close to luxury car on the inside for sound.
Joined: Jul 1999
Posts: 12,089
Likes: 125
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Was I too Optimistic ? TPI L98 Power
Not optimistic.... You have to take advantage of critical amount of torque. Not high rpm lt1 or ls1 ...i seen a 383 with procharger and Afr heads tuned and tweaked put it right right in air facing sky. It was 9.09 at 138.he tuned the hell out of it and tpi smart.tpi scavenge effect like headers they are desinged to be Torque monsters. Keep gears low at 3.12 or 3.23 ..any higher puts you out of torque and horsepower peak. Unless t56 6 speed manual then 373 potential option depending on full application. Get back.... I'm tpi....conisore. lol
-- Joe
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Was I too Optimistic ? TPI L98 Power
9.09 at 138 is letting out way early and costing which means its well into the 8’s at very high mph
Might be possible but hard to believe without more data
Did you mean 9.90? I can buy that. I tuned 550 whp on low boost on a 383 tpi and it easily would make 9 sec power if it didnt throw belts. Alignment problem
Might be possible but hard to believe without more data
Did you mean 9.90? I can buy that. I tuned 550 whp on low boost on a 383 tpi and it easily would make 9 sec power if it didnt throw belts. Alignment problem
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Was I too Optimistic ? TPI L98 Power
9.09 at 138 is letting out way early and costing which means its well into the 8’s at very high mph
Might be possible but hard to believe without more data
Did you mean 9.90? I can buy that. I tuned 550 whp on low boost on a 383 tpi and it easily would make 9 sec power if it didnt throw belts. Alignment problem
Might be possible but hard to believe without more data
Did you mean 9.90? I can buy that. I tuned 550 whp on low boost on a 383 tpi and it easily would make 9 sec power if it didnt throw belts. Alignment problem
I'm sorry, but I don't believe a factory TPI Casting (Base, Runners, and Plenum) are running 9's no matter how much porting and matching is done.
Now if by TPI we mean a TPI computer is controlling the system but everything else is changed, sure.
Joined: Sep 1999
Posts: 4,353
Likes: 308
From: NJ
Car: 92 Firebird
Engine: 4.8 LR4
Transmission: T56
Axle/Gears: 3.45 9 Bolt
Member

Joined: May 2013
Posts: 232
Likes: 0
From: ORLANDO FL
Car: 91 RS VERT
Engine: 305 9.67 2.02 58 cc 282 480 108 LC
Transmission: 700R4
Axle/Gears: 4.11 POSI
Re: Was I too Optimistic ? TPI L98 Power
Take the Audi to a car show and nobody will look at it unless they need a bumper to tie their shoe on lol .....but everyone will take a quick look at a third gen ......... Joined: Jul 1999
Posts: 12,089
Likes: 125
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Was I too Optimistic ? TPI L98 Power
The only thing they associate thirdgens with are trailer parks.
-- Joe
Joined: Mar 2014
Posts: 4,553
Likes: 806
From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: Was I too Optimistic ? TPI L98 Power
Have to say mine gets a lot of attention at carshows. Does well. Some people like to see something other than 57 chevys, 68 Camaros, etc.
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Was I too Optimistic ? TPI L98 Power
Wished I had left my 'Vette at home and taken mine.
The Trailer park thing is changing as those have all rotted away into oblivion after 30 years, but a clean IROC... it gets attention. I know
Senior Member




Joined: Mar 2014
Posts: 571
Likes: 10
From: Indy
Car: 88 IROC-Z
Engine: GEN 4 LY6 (going forged 408)
Transmission: 60E (going RPM LEVEL 6 4L80E)
Axle/Gears: 7.5" 3.42 (staying...)
Joined: Jul 1999
Posts: 12,089
Likes: 125
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Was I too Optimistic ? TPI L98 Power
Need to finish your build first buddy. 
I like going to both. The builds are cooler at the car shows, more attention to detail. Fast cars at the track for sure, but most of them look like mine. Not show quality, just go quality.
-- Joe

I like going to both. The builds are cooler at the car shows, more attention to detail. Fast cars at the track for sure, but most of them look like mine. Not show quality, just go quality.
-- Joe
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Was I too Optimistic ? TPI L98 Power
I go support my friends cars. Mine will get done in due time but for now its not my main concern. Trying to get my buddy’s car to break 6.99...yeah 1/4 mile street capable, full safety
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Posts: 2,406
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From: New England
Car: 1988 IROC Z Convertible
Engine: 305 TPI (LB9)
Transmission: 700 R4
Axle/Gears: G80 GU2
Re: Was I too Optimistic ? TPI L98 Power
The trailer park thing happened when people would buy trashed or beat third gens or IROCs and put a spoiler on top of a spoiler, have 3-different colored body panels, hood pins, Summit, Edelbrock, etc stickers covering the back window, interior ripped apart except seats, rusty American Racing wheels, etc..
The reason that happened is because third gens were very eye catching and such a big hit that as soon as the people that could afford them new trashed them, the leftovers went to people with no taste and gave them a bad name.. by the 90s there were few IROCs that weren’t heavily altered by bad taste..
People forgot how awesome they were in brand new condition..
Joined: Apr 2009
Posts: 378
Likes: 17
From: Ontario, Canada
Car: 1987 IROC-Z
Engine: L98 5.7L
Transmission: MD8 700R4
Axle/Gears: G80 GW6 3.27:1
Re: Was I too Optimistic ? TPI L98 Power
I guess it could be somewhat regional/age group based. I have a Chevelle SS that is an older repaint from the 80s and is badly showing its age up close, but from 20'+ looks decent and has newer style 17" wheels, lowered ~1". It gets a lot more attention and comments at a gas station than my 33k mile iroc. However, I will say that when someone says something more than "nice car" it is someone who really loves third gens and ends up being a conversation rather than a 5 second exchange.
Whoa, this was a side track, sorry to the OP.
Whoa, this was a side track, sorry to the OP.
Re: Was I too Optimistic ? TPI L98 Power
Unless he is bouncing off the rev limiter in high gear. 1/8th mile car running the 1/4?
I'm sorry, but I don't believe a factory TPI Casting (Base, Runners, and Plenum) are running 9's no matter how much porting and matching is done.
Now if by TPI we mean a TPI computer is controlling the system but everything else is changed, sure.
I'm sorry, but I don't believe a factory TPI Casting (Base, Runners, and Plenum) are running 9's no matter how much porting and matching is done.
Now if by TPI we mean a TPI computer is controlling the system but everything else is changed, sure.
Senior Member

Joined: Nov 2004
Posts: 768
Likes: 32
From: Lansing, MI
Car: 1988 IROC-Z
Engine: 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.45
Re: Was I too Optimistic ? TPI L98 Power
no it was ported everything cowl hood. .. Had it worked I didn't believe it til I seen in hit the bumper.. . It was fastest tpi car with power adder I've ever seen.... It was insane ... Twin ported runners.... Vortech supercharged ,it was insane. Nothing on YouTube can compete.on bumper for 60 ft..... 700 r4 built with Ford 9 inch. Don't believe me...dont change it was real and happened.dad and son built it. ...tuned by IDK.
Joined: Sep 1999
Posts: 4,353
Likes: 308
From: NJ
Car: 92 Firebird
Engine: 4.8 LR4
Transmission: T56
Axle/Gears: 3.45 9 Bolt
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Joined: Nov 2008
Posts: 2,093
Likes: 175
From: Milwaukee
Car: 92 Firebird, 77 Trans Am SE, 86 Z28
Engine: 5.7 HSR, T/A 6.6, empty
Transmission: T-5, TH350, T-5
Axle/Gears: 3.08 posi, 3.23 posi, 3.23
Re: Was I too Optimistic ? TPI L98 Power
it was also the fastest tpi with a power adder that had a supercharger?
Last edited by aliceempire; Jul 23, 2018 at 07:22 PM. Reason: sometimes you should proof read what you wrote!
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