CHP article on 12 second TPI car
CHP article on 12 second TPI car
I finally found the CHP article that i mentioned some weeks ago.
its in the october 2001 issue. A quick review
355 factory roller block and Rotating Assy.
l98 cnc heads
tpis cam ZZ-9 212/226 w 1.6 rockers .515/.555
edelbrock TES 1 5/8 headers
tpis manifold, runners and throttle body
ported plenum 24 lb injectors
custom prom
random tech 3 in cat/exhaust
700r4, 3.42, 12inch converter
random torque arm, lca's, and relocating brackets
MT et slicks
12.384/111.06
its in the october 2001 issue. A quick review
355 factory roller block and Rotating Assy.
l98 cnc heads
tpis cam ZZ-9 212/226 w 1.6 rockers .515/.555
edelbrock TES 1 5/8 headers
tpis manifold, runners and throttle body
ported plenum 24 lb injectors
custom prom
random tech 3 in cat/exhaust
700r4, 3.42, 12inch converter
random torque arm, lca's, and relocating brackets
MT et slicks
12.384/111.06
How is that minimal mods?
he probably means that it doesnt have a "wild cookoo cabonzo" cam, or a huge blower/turbo, or a 500 shot of nitrous.
It seems like the kinda mods some guys on here do and complain about only running 14's? i think a good amout of this ET probably comes from some excellent traction too.
he probably means that it doesnt have a "wild cookoo cabonzo" cam, or a huge blower/turbo, or a 500 shot of nitrous.
It seems like the kinda mods some guys on here do and complain about only running 14's? i think a good amout of this ET probably comes from some excellent traction too.
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From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
The article isn't very complete. There are a lot of things they don't say about how they were able to do it.
The minimal mods also include Aluminum Vette heads that are "modified".
They also briefly mention a Holley Pro Strip Annihilator ignition system.
The minimal mods also include Aluminum Vette heads that are "modified".
They also briefly mention a Holley Pro Strip Annihilator ignition system.
check out more performance. This Mike Osucha seems to really know what he is doing
http://www.moreperformanceinc.com/
http://www.moreperformanceinc.com/
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From: Orange, SoCal
Car: 1990 Pontiac Trans Am
Engine: 355 TPI siamesed runners
Transmission: Tremec T56
Axle/Gears: 12-Bolt 3.73
I heard that is a repeat from an article they first printed in the early 90's. The car really has AFR heads, not L98's. That'd make a big difference.
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From: Readsboro, VT
Car: 85 IROC-Z / 88 GTA
Engine: 403 LSx (Pending) / 355 Tuned Port
Transmission: T56 Magnum (Pending) / T5
Axle/Gears: 3.42 / ?
Originally posted by laiky
Says CNC L98 corvette heads. That is what Lingenfelter uses. i believe they ae comperable to AFR's once there properly done.
Says CNC L98 corvette heads. That is what Lingenfelter uses. i believe they ae comperable to AFR's once there properly done.
The L98 heads can be made to work very, very well.
12.3 is still awful fast for that combo.
This article came up in the past, its what i based my performance expectations on, with the motor in the sig a ran a 14.45. I wanted to shoot myself but in my defense my posi is broken, i was on street tires and i am running a walker cat plus an electric q jet.
I will be doing alot of work this winter.
I will be doing alot of work this winter.
I still say u have a 13 sec car, just from the MPH u got on your run. With some traction and a little tuning, not to mention some practice you will be in the low 13's at least. Besides, it was a lot better than the 15 sec blast I ran, LOL.
Well thanks i was thinking i could have squeaked into the 13's that day. I think i was shifting too high. With the cat i have i think i'm too restricted at 5500-6000 rpm
i would like to try again at 5000-5200
i'm installing a backpressure gauge tommorrow and making my test pipe. I am really curious to see what the difference is.
i would like to try again at 5000-5200
i'm installing a backpressure gauge tommorrow and making my test pipe. I am really curious to see what the difference is.
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From: San Antonio, TX
Car: Damn
Engine: This
Transmission: New Stuff
Yeah, those were not aluminum L98 heads on that engine. You can tell by looking at the picture in the article, they are not the L98 casting. They look like AFR's like Kevin said.
I'd imagine there was even more mis-information than that in that article. I mean when you misprint something as important as the heads, who knows what else is wrong.
I'd imagine there was even more mis-information than that in that article. I mean when you misprint something as important as the heads, who knows what else is wrong.
The only picture of the heads in the article is a shot of the engine bay where the front of the head is visible where the AC compressor was. I have afr's and i cant tell you that these are them.
here's a quote from the article:
"Although the selection of aftermarket heads is almost unlimited, there's a strange satisfaction to be derived from building a thumper engine from stock castings, to thet end we chose a set of 88-91 corvette L98 alluminum head castings modified by CNC Cylinder heads"
it goes on ton explain how the builder uses REV stainless valves that he cuts down to 2.00/1.56 from 2.02/1.6 to be able to retain the stock valve seats.
Its very specific for a mistake, besides as mentioned before, once CNC'd these heads flow as good as AFR's. Even if they are AFR's i already have them on my motor and i still am lacking the performance this article claims.
here's a quote from the article:
"Although the selection of aftermarket heads is almost unlimited, there's a strange satisfaction to be derived from building a thumper engine from stock castings, to thet end we chose a set of 88-91 corvette L98 alluminum head castings modified by CNC Cylinder heads"
it goes on ton explain how the builder uses REV stainless valves that he cuts down to 2.00/1.56 from 2.02/1.6 to be able to retain the stock valve seats.
Its very specific for a mistake, besides as mentioned before, once CNC'd these heads flow as good as AFR's. Even if they are AFR's i already have them on my motor and i still am lacking the performance this article claims.
Here’s an old link with my comments about this below.
https://www.thirdgen.org/techbb2/showthread.php?threadid=1904&highlight=CNC
Yep,, it's the same build as the HardRock. Funny how the people that builds the engines change from story to story though. I even have one 94 article where the engine was built by RHS and the engine has AFR heads and the TPiS "blueprint cam". The dyno numbers matched exactly or were within a couple horses of the HP listed for the HardRock build. Two different dynos?? Two different heads?? Two different camshafts?? Makes you wonder huh? IF it's not total BS about CNC Cylinder Heads doing the port work,,,the L98 heads supposedly received CNC porting, valves, springs,and machine work from CNC Cylinder Heads. They get $1300 - $1600 (depending on the springs locks and retainers) to set up the customer supplied "bare" cylinder heads. Hardly what I'd call couch change,, so don't feel bad friend!!! Without this type or similar porting on the heads, I'd think most people's car would have a hard time running 13.0s,, even applying all the "tricks" that were not mentioned.
I have run in the mid 12's over 112mph with a very similar combination (lesser box stock G1 TFS heads and no suspension work) with literally everything removed from the car that was not necessary to get it down the 1/4 in 40 degree weather. That same combination at full street weight - including the air compressor (skinnies and ET Steets) in 85 degree weather ran 12.90's with the modified SLP runners. So if I wanted to look like some big shot magazine guru would I report I ran a 12.90 or 12.50 and leave off the weight and weather info? It's all about what they don't tell you.
https://www.thirdgen.org/techbb2/showthread.php?threadid=1904&highlight=CNC
Yep,, it's the same build as the HardRock. Funny how the people that builds the engines change from story to story though. I even have one 94 article where the engine was built by RHS and the engine has AFR heads and the TPiS "blueprint cam". The dyno numbers matched exactly or were within a couple horses of the HP listed for the HardRock build. Two different dynos?? Two different heads?? Two different camshafts?? Makes you wonder huh? IF it's not total BS about CNC Cylinder Heads doing the port work,,,the L98 heads supposedly received CNC porting, valves, springs,and machine work from CNC Cylinder Heads. They get $1300 - $1600 (depending on the springs locks and retainers) to set up the customer supplied "bare" cylinder heads. Hardly what I'd call couch change,, so don't feel bad friend!!! Without this type or similar porting on the heads, I'd think most people's car would have a hard time running 13.0s,, even applying all the "tricks" that were not mentioned.
I have run in the mid 12's over 112mph with a very similar combination (lesser box stock G1 TFS heads and no suspension work) with literally everything removed from the car that was not necessary to get it down the 1/4 in 40 degree weather. That same combination at full street weight - including the air compressor (skinnies and ET Steets) in 85 degree weather ran 12.90's with the modified SLP runners. So if I wanted to look like some big shot magazine guru would I report I ran a 12.90 or 12.50 and leave off the weight and weather info? It's all about what they don't tell you.
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From: San Antonio, TX
Car: Damn
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Yeah, in that picture of the engine you can see the front of the driver's side head.
From my experience,
If you look at the machined surface of heads where the accesory bolts holes are, they have kinda a specific look.
On aluminum L98's that machined part covers nearly the whole side of the head and has straight edges, while on many aftermarket heads the machined part has a double hump look to it, leaving part of the head with a cast finish. I had a set of the same casting late model al. L98 heads, they weren't like the ones in the picture.
Look at any set of heads and you'll see what I'm talking about.
Unless castings and machining vary that much from head to head, those supposedly al. L98 heads should look like all the other al. L98 heads I've seen and owned. maybe they are different, I guess it really doesn't matter.
From my experience,
If you look at the machined surface of heads where the accesory bolts holes are, they have kinda a specific look.
On aluminum L98's that machined part covers nearly the whole side of the head and has straight edges, while on many aftermarket heads the machined part has a double hump look to it, leaving part of the head with a cast finish. I had a set of the same casting late model al. L98 heads, they weren't like the ones in the picture.
Look at any set of heads and you'll see what I'm talking about.
Unless castings and machining vary that much from head to head, those supposedly al. L98 heads should look like all the other al. L98 heads I've seen and owned. maybe they are different, I guess it really doesn't matter.
Last edited by '87FAKE-IROC-Z; Oct 29, 2002 at 12:42 AM.
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