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BIG improvement!!!

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Old Mar 22, 2007 | 08:05 PM
  #51  
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Re: BIG improvement!!!

i still say stock l98 350 tpi motors are capable of consistant 14.1-14.2 runs without timing adjustments b/c thats what my car ran stock
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Old Mar 23, 2007 | 09:52 PM
  #52  
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From: Lubbock, Tx
Car: 1991 Camaro Z28
Engine: L98 5.7 350 TPI
Transmission: Brand New (again) 700r4
Axle/Gears: GM 10 bolt 7.625 W/ TrueTrac 3.23
Re: BIG improvement!!!

It really depends who you talk to. It all depends on track prep, condition of tires, and suspension condition. I believe that GM claims that a stock L98 runs like a 14.4. Don't forget that I did mention that I was running on bald @$$ street tires too. Maybe I could run like 14.1 without timing adjustment, but at that time, the adjustment helped me out.
----------
Also, If you look at my times and my trap speed, they are pretty good. Even without the timing advance. so I believe it was a factor with traction in my case.

Last edited by Imthebriman; Mar 23, 2007 at 09:54 PM. Reason: Automerged Doublepost
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Old Mar 26, 2007 | 04:11 AM
  #53  
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Re: BIG improvement!!!

13’s are definitely possible. I ran a 13.59@100 in my formula 350 with the only major hard parts changes being an SLP intake and cat back.

As far as adjustable fpr’s… I just made my stock one adjustable:
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Old Mar 27, 2007 | 04:42 PM
  #54  
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From: Lubbock, Tx
Car: 1991 Camaro Z28
Engine: L98 5.7 350 TPI
Transmission: Brand New (again) 700r4
Axle/Gears: GM 10 bolt 7.625 W/ TrueTrac 3.23
Re: BIG improvement!!!

Originally Posted by 83 Crossfire TA
13’s are definitely possible. I ran a 13.59@100 in my formula 350 with the only major hard parts changes being an SLP intake and cat back.

As far as adjustable fpr’s… I just made my stock one adjustable:
Hey crossfire, How did you go about making your stock fpr adjustable. I am really curious as how to do it. Does it function well? Please let me know.
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Old Apr 7, 2007 | 02:37 PM
  #55  
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Re: BIG improvement!!!

Took the stock housing, pounded the top contour flat to give the washer somepace to go, drilled it, added a T-nut (here’s a back side showing it with it’s broken off tabs and epoxied in):

The rest is like what’s in that picture.

Works great. Eventually I replaced it with a Holley unit which so far ahs failed and replaced 2x…
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Old Apr 7, 2007 | 07:04 PM
  #56  
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Car: 89 RS, 92 Z28
Engine: 305 TBI, 350 TPI
Transmission: 700R4 Both Cars
Axle/Gears: 3.23 Posi.. 4 wheel disc both cars
Re: BIG improvement!!!

Raptor, you only got about a tenth of a second when you went from 2.77 gears to a 3.73??????? I thought there would be more of a difference.......
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Old Apr 7, 2007 | 07:33 PM
  #57  
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Car: 92rs
Engine: 350
Transmission: 350
Axle/Gears: 3.73/Moser 12bolt
Re: BIG improvement!!!

Originally Posted by Gallileo60
Raptor, you only got about a tenth of a second when you went from 2.77 gears to a 3.73??????? I thought there would be more of a difference.......
me too but she wants 4th at about 1000' .I just found the mod to shift into 4th at wot and will be doing it asap .will post new times in drag race forum when i have them .

crossfire : cool idea i may try that 1 also.
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Old Apr 7, 2007 | 07:34 PM
  #58  
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Car: 89 RS, 92 Z28
Engine: 305 TBI, 350 TPI
Transmission: 700R4 Both Cars
Axle/Gears: 3.23 Posi.. 4 wheel disc both cars
Re: BIG improvement!!!

83 crossfire, does the same thing about increasing fuel pressure apply to TBI motors???? Thanks, Tom
----------
Originally Posted by raptor80dad
me too but she wants 4th at about 1000' .I just found the mod to shift into 4th at wot and will be doing it asap .will post new times in drag race forum when i have them .

crossfire : cool idea i may try that 1 also.
Ok, cool I look forward to hearing what happens....How hard was it to make it shift into 4th at WOT..........

Last edited by Gallileo60; Apr 7, 2007 at 07:38 PM. Reason: Automerged Doublepost
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Old Apr 7, 2007 | 07:39 PM
  #59  
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Re: BIG improvement!!!

Originally Posted by 83 Crossfire TA
Took the stock housing, pounded the top contour flat to give the washer somepace to go, drilled it, added a T-nut (here’s a back side showing it with it’s broken off tabs and epoxied in):
The rest is like what’s in that picture.

Works great. Eventually I replaced it with a Holley unit which so far ahs failed and replaced 2x…
Why didn't you put your modded FPR back in instead of buying more Holleys?
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Old Apr 8, 2007 | 04:15 AM
  #60  
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Re: BIG improvement!!!

Originally Posted by Gallileo60
83 crossfire, does the same thing about increasing fuel pressure apply to TBI motors????
TBI engines are supposed to run at 9-12psi, but usually run best at 12-14psi. TBI fuel pressure regulators are pretty much adjustable from the factory, they just have a cap pushed into the hole over the screw or a drop of braze dropped in there, just disassemble and remove whatever is in the way. I’ve taken the end of the adjuster screw, bored a hole in it, threaded it and added an allen head to make it easier to turn, but that’s not necessary.

Here’s the adjuster screw assembly and the plate that the spring rides on inside the housing in a TBI one (it’s sitting in a hole in the top of a workmate type table), cut and threaded for the allen head sitting next to it:


And here’s the assembled deal


If you can’t tell, I can’t leave anything well enough alone…

Originally Posted by firstfirebird
Why didn't you put your modded FPR back in instead of buying more Holleys?
Well, I got the holly because I liked the pretty machined **** on the top rather then taking a ½” wrench with me to the track and thought “hey, this thing has to be better than some cobbled piece of crap that I made…” (usually the same thought I have before I get pissed off at assorted aftermarket manufacturers), and I was getting free warranty replacements on the holley till I decided that I’m going to do something totally different with the car. FWIW, with the wrench I could adjust my setup on the fly, the holley deal you really have to pull the vacuum lines to adjust. In retrospect I should have never wasted my time and money.
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Old Apr 8, 2007 | 07:07 AM
  #61  
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Car: 89 RS, 92 Z28
Engine: 305 TBI, 350 TPI
Transmission: 700R4 Both Cars
Axle/Gears: 3.23 Posi.. 4 wheel disc both cars
Re: BIG improvement!!!

Thanks, Crossfire......Nice pics......
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Old Apr 8, 2007 | 06:54 PM
  #62  
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From: Lubbock, Tx
Car: 1991 Camaro Z28
Engine: L98 5.7 350 TPI
Transmission: Brand New (again) 700r4
Axle/Gears: GM 10 bolt 7.625 W/ TrueTrac 3.23
Re: BIG improvement!!!

Yeah, thanks Crossfire. Those pics and descriptions helped out alot. I think I may end up fabbing my stock one as well.... But I might use another aftermarket one instead....Will bumping up my Fuel pressure help me out in the 1/4? just curious.....
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Old Apr 8, 2007 | 08:50 PM
  #63  
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Re: BIG improvement!!!

I found my crossfire (TBI) car ran best at 14psi, my L05 truck at 13-14psi.

My tpi Formula 350 ran _fastest_ at ~54psi, but also left some black soot on the back bumper at that pressure, so I would assume that it was rich somewhere at cruise or part throttle.

So yea, I know at least in those cases it helped, but of course I actually tested it with back to back track runs in all 3 cases.
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Old Apr 10, 2007 | 05:23 PM
  #64  
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From: Lubbock, Tx
Car: 1991 Camaro Z28
Engine: L98 5.7 350 TPI
Transmission: Brand New (again) 700r4
Axle/Gears: GM 10 bolt 7.625 W/ TrueTrac 3.23
Re: BIG improvement!!!

Is 54psi too much for the street? Just curious since my car is a daily driver.
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Old Apr 10, 2007 | 11:34 PM
  #65  
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Re: BIG improvement!!!

I never saw any difference in gas mileage or issues other then that I started seeing some carbon/soot on the bumper above the tailpipe. The car passed emissions that way also. My $.02, try it and run it where it runs the best. I think mine started at around 42 or 43psi stock, and I gave it 2 more psi and ran faster, kept giving it a little more pressure till it slowed down and then backed off a little.
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Old Apr 11, 2007 | 01:26 AM
  #66  
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Car: 89 RS, 92 Z28
Engine: 305 TBI, 350 TPI
Transmission: 700R4 Both Cars
Axle/Gears: 3.23 Posi.. 4 wheel disc both cars
Re: BIG improvement!!!

Originally Posted by raptor80dad
13's are real possible.

best w/stock 2.77 posi rear 13.65 @ 99 mph 1.89 60'
best w/3.73 13.54 @ 98mph 1.81 60'

stock motor w/no back seats , no cat ,free flow muffler , stock exh. manifolds
tci trans w/app 1500-2000 stall . ac + smog are gone . oh yeah 155,??? miles
electric w/ pump gave me 1 tenth .

but it seems I am stuck here so headers are next .


oh yeah , on drag radials

let us know how you do next time.
Damn, that is crazy with that gear...........How much does that car weigh?????? Mine ran 15.3....Im jelous....must have a 3.73.................Is that a 305, or a 350???????
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Old Apr 11, 2007 | 06:06 AM
  #67  
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From: Lubbock, Tx
Car: 1991 Camaro Z28
Engine: L98 5.7 350 TPI
Transmission: Brand New (again) 700r4
Axle/Gears: GM 10 bolt 7.625 W/ TrueTrac 3.23
Re: BIG improvement!!!

Originally Posted by Gallileo60
Damn, that is crazy with that gear...........How much does that car weigh?????? Mine ran 15.3....Im jelous....must have a 3.73.................Is that a 305, or a 350???????
It says he has 3.73s i think. that is a pretty decent time.... also says he has a 350
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Old Apr 12, 2007 | 02:46 AM
  #68  
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Car: 89 FORMULA 350
Engine: 5.7 L98
Transmission: 700R4
Axle/Gears: 9 BOLT/ 3.27 GEARS
Re: BIG improvement!!!

Check out my sig, I'm running rather decent with minimal mods too! I believe my barely modded 5.7 car would run mid- high 13's with some ecm tuning and stickier tires. But I'm about to install a 75 shot NOS kit and UMI subframes, lower control arms, and the adjustable panhard rod next week. Hopefully I can break 12's!!! I won't be doing any tuning or tire upgrades, but I'm gonna see how she runs anyways. I'll keep You all updated with my times. Later On
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Old Apr 12, 2007 | 07:45 AM
  #69  
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From: Lubbock, Tx
Car: 1991 Camaro Z28
Engine: L98 5.7 350 TPI
Transmission: Brand New (again) 700r4
Axle/Gears: GM 10 bolt 7.625 W/ TrueTrac 3.23
Re: BIG improvement!!!

Awesome Rik! Keep us updated!!!
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