Do I have a bad TPI combo?
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Junior Member
Joined: May 2009
Posts: 15
Likes: 0
From: Texas
Car: 1992 Z28
Engine: 6.0
Transmission: 4L80E
Axle/Gears: 3.42
Do I have a bad TPI combo?
I have recently rebuilt my motor in my 92 z28 with a few add ons. I have installed AFR 180cc heads, ZZ4 cam, TPIS manifold, Hooker shorty headers, Bosch III injectors, Catco high flow converters and a CNC ported Plenum. The internals of the block are new and I have replaced just about every sensor except the O2 which I'm going to install a new heated one tomorrow. The motor just does not seem to have the power that I thought it would and I know I need to reprogram the ecm but should'nt run better or at least as good as it did when it when I bought the car back in 94?
Any suggestion and or advice is greatly appreciated.
Thanks,Patrick
Any suggestion and or advice is greatly appreciated.
Thanks,Patrick
Supreme Member

Joined: Jan 2003
Posts: 2,043
Likes: 3
From: San Diego
Car: 1994 Trans Am
Engine: LT1
Transmission: Auto
Axle/Gears: 3.23
Re: Do I have a bad TPI combo?
How many miles are on the motor? Have you done any before and after track or Gtec runs with it? Did you set the timing correctly? I'm sure a tune will help being SD. A maf car is more easy with H/C mods. That's always scary with TPI, you never know if the combo will work with all the different parts.
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Joined: Feb 2007
Posts: 730
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From: Minneapolis, MN
Car: currently a 91 G92.
Engine: 305TPI
Transmission: Borg Warner WC 5 speed
Axle/Gears: 3.42
Re: Do I have a bad TPI combo?
Get the car tuned and you will be smiles ear to ear. I know exactly how you are feeling. I had less than you done to my car and very similarly to your experience was very disappointed with how the car performed compared to before. I custom wide band tune made a huge difference. It made the car run better and cooler, sound better, and scream. It felt like it gained a good 50 horses after the tune.
Am absolutely certain that your car needs a tune even more than mine did.
Am absolutely certain that your car needs a tune even more than mine did.
Thread Starter
Junior Member
Joined: May 2009
Posts: 15
Likes: 0
From: Texas
Car: 1992 Z28
Engine: 6.0
Transmission: 4L80E
Axle/Gears: 3.42
Re: Do I have a bad TPI combo?
Thanks for the response guys. Currently I have a little over 3000 miles on the motor it is my daily driver. I did not do any before and after because the motor was worn out it had 181000 hard miles on it and was just weak. I set the timing at 6* before tdc. Like I said I knew that I would have to reprogram/replace the ecm but I thuoght it would run better then it does with out programing and then possibly free up a little more power with a good tune.
Does anyone have any suggestion for tuning? I have looked locally but I only found 1 shop (which is now closed) that would do the programming but for the money it seems like I would be better off getting a system to do it my self. Would something like the EBL Flash System work or do I need to look at burning my own chips?
Does anyone have any suggestion for tuning? I have looked locally but I only found 1 shop (which is now closed) that would do the programming but for the money it seems like I would be better off getting a system to do it my self. Would something like the EBL Flash System work or do I need to look at burning my own chips?
Last edited by patrick92z28; Oct 18, 2009 at 09:52 AM.
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: Do I have a bad TPI combo?
Did you replace runners too with highflow stuff?
Definately needs tuned and you'll feel good difference. That combo is fine
Definately needs tuned and you'll feel good difference. That combo is fine
Thread Starter
Junior Member
Joined: May 2009
Posts: 15
Likes: 0
From: Texas
Car: 1992 Z28
Engine: 6.0
Transmission: 4L80E
Axle/Gears: 3.42
Re: Do I have a bad TPI combo?
No I have not gotten the runners yet. I kinda blew my load on the build! I thought I should get it tuned and then down the road up grade the runners. I was just worried that I had made a mistake in my combo by the way it was running.
Senior Member
iTrader: (1)
Joined: Feb 2007
Posts: 730
Likes: 0
From: Minneapolis, MN
Car: currently a 91 G92.
Engine: 305TPI
Transmission: Borg Warner WC 5 speed
Axle/Gears: 3.42
Re: Do I have a bad TPI combo?
If you get the car tuned now and the runners later, you are still going to need to readjust the tune after the new runners are put in.
Get the car tuned. Any place that does LT1 or LS1 wide band tuning should be able to do yours. You are going to need a different chip for your car that is re programmable since the stock chip can not be reprogrammed.
You can also invest into getting the equipment and learning to do it yourself. There is plenty of good info on how to get started on that here on this board.
I recommend the latter approach since you will be able to adjust the tune of your car yourself any time you upgrade something.
I went without a tune, like you, for about 12K miles. Needless to say, the spark plugs were done by that point. My fuel economy was crap. My car ran hotter than before. And I was unsatisfied by the results produced by $4500 invested into the motor. After my car got a custom wide band tune at a performance shop that specializes in f-bodies, it became a beast. The difference was day and night.
It costs about $250 to get the tuning equipment. With a bit of reading and some help from some of the members on this board, you should be on the way to getting your car to run the way it should.
Get the car tuned. Any place that does LT1 or LS1 wide band tuning should be able to do yours. You are going to need a different chip for your car that is re programmable since the stock chip can not be reprogrammed.
You can also invest into getting the equipment and learning to do it yourself. There is plenty of good info on how to get started on that here on this board.
I recommend the latter approach since you will be able to adjust the tune of your car yourself any time you upgrade something.
I went without a tune, like you, for about 12K miles. Needless to say, the spark plugs were done by that point. My fuel economy was crap. My car ran hotter than before. And I was unsatisfied by the results produced by $4500 invested into the motor. After my car got a custom wide band tune at a performance shop that specializes in f-bodies, it became a beast. The difference was day and night.
It costs about $250 to get the tuning equipment. With a bit of reading and some help from some of the members on this board, you should be on the way to getting your car to run the way it should.
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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: Do I have a bad TPI combo?
stock runners are killing your combo.... you need to upgrade now and get it tune to really feel a difference
Base and heads will flow well, but its trying to suck through stock 200 cfm runners and thats just like a restrictor plate in racing... your car needs to breathe.
So dont feel bad that its not as quick as you thought it would be.. it will open up alot with runners
Base and heads will flow well, but its trying to suck through stock 200 cfm runners and thats just like a restrictor plate in racing... your car needs to breathe.
So dont feel bad that its not as quick as you thought it would be.. it will open up alot with runners
Thread Starter
Junior Member
Joined: May 2009
Posts: 15
Likes: 0
From: Texas
Car: 1992 Z28
Engine: 6.0
Transmission: 4L80E
Axle/Gears: 3.42
Re: Do I have a bad TPI combo?
Does any one have experience with the EBL Flash system from Dynamic EFI I really like the idea of being able to tune with a laptop without removing anything. If I could use this system I'd be able to adjust the tune at any time like after I install some new runners!
Member
Joined: Jan 2008
Posts: 194
Likes: 0
From: close to Wichita Kansas
Car: '91 RS CP now is the son's driver
Engine: CP =3.1, will get V-8 maybe someday
Transmission: stock
Axle/Gears: 3.42 posi W/ disks
Re: Do I have a bad TPI combo?
that is the system that I purchased, but I havent built the motor yet, I an going with a 327 TPI set up
Member
Joined: Dec 2004
Posts: 210
Likes: 0
From: Rhode Island
Car: '87 S10 Blazer & '91 RS
Engine: L98 & L03
Transmission: 700R4 & T5
Axle/Gears: 10 Bolt/3.73/3.42
Re: Do I have a bad TPI combo?
To my knowledge, the EBL is for the TBI computers, not your '730. I picked up the Ostrich 2 from moates, and I love it. Combined with the cable I got from ALDLcables.com, I can tune real time. Makes things much easier, as you can adjust and then test under the same conditions.
Thread Starter
Junior Member
Joined: May 2009
Posts: 15
Likes: 0
From: Texas
Car: 1992 Z28
Engine: 6.0
Transmission: 4L80E
Axle/Gears: 3.42
Re: Do I have a bad TPI combo?
It does use the TBI ecms what I was looking at was converting my my wire harness to utilize the TBI ecm with the EBL system.
What is the Ostrich 2? I was looking at the EBL because of the ability to tune with a laptop without have to remove anthing like a chip.
What is the Ostrich 2? I was looking at the EBL because of the ability to tune with a laptop without have to remove anthing like a chip.
Member
Joined: Aug 2005
Posts: 177
Likes: 0
From: Ct valley
Car: 88 TA
Engine: TBI 5.7
Transmission: 700R4
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