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Discussion Starter · #1 ·
hey guys
i'm new to this forum but i'm a part of supraforums.com

i just recently sparked an interest into GN's. i knew they were great cars but what got me interested is i found out they were 3.8L turbocharged intercooler V6's!


i own a MKIII supra turbo so i know alot about turbo cars and modifications, so i'm not COMPLETELY stupid


i've heard of alot of people running 1000+ RWHP on GN engines (buick 231 blocks right?), so i'm wondering, do these people run standalone ECU's or do they just chip their existing computers to run the 1000+ RWHP and 9sec 1/4 mile passes?

also, how much RWHP can the engine and tranny (a turbo 350 right?) support before they need to be rebuilt?

i heard the GN turbos can handle 20psi, what kind of 1/4 mile times are we looking at with a GN running 20psi, proper fuel, intake and exhaust modifications?

i know it's alot of questions but if you guys could answer any of them i'd be really greatful
thanks again!!

Chris
 

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Go to www.gnttype.org for very thorough information. The car has a 200R4 transmission. The stock turbo can boost over 20psi, but the stock turbo only flows about 550 CFM and the charged air is going to be hotter than an upgraded turbo. The stock parts are very strong, but these cars need more than bolt-ons when going deep into the 10's and 9's mechanically safe. But 12's and 11's...not too tough. Most of the serious guys seem to be using Max Effort adjustable chips. Since you're not new to turbos, you probably won't blow a headgasket too quickly.


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1987 GN 14" K&N, adj. wastegate, adj. FPR, XP Armstrong hotwired, 160*-stat, Hooker 2.5" catback exaust, Thrasher chips, shift kit, trans cooler, vdo boost/oil/temp guages, scanmaster v2.1, Kirban's front/rear frame braces, Hotchkis lower contol arms, variable rate rear springs, GNX wanna-be rims, and the rest is stock as far as I can tell...or too meaningless to list.

1987 Cavalier Z24 daily driver. 3-chamber flowmaster and 135db worth of stereo.

Shaun

[This message has been edited by shaunchrisc (edited May 29, 2002).]
 

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Discussion Starter · #3 ·
hehe ok thanks for the info

i see u guys use turbonetics ALOT
turbonetics has a HORRIBLE reputation in the supra cirle...why do you guys continue to use them?

any of you guys run T88's or T51R SPL's?

oh also, which is better? the tranny found in GN's or a turbo350?
 

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The 200-4R can be built to stand up to a high 9sec car, and is preferred by most for drivability.

Not too many people run Turbonetics turbos, mostly just wastegates.

The 9sec cars you see are typically 4.1L or 4.5L Stage 2 engines. Which is the motorsports components that were used in 80s Nascar (Busch Grand National) and Indy cars. Some are 3.8L or even 3.0L Stage 2s but most are larger.
 

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Except for the fact that they share the same number of cylinders (6), there's very very little similarity between a stock block and a stage II block. For all intents and purposes the stageII is a completely different animal, and is what is needed to support horsepower levels in excess of 600-700. A properly prepped stock block can support up to 600-700 HP, but it's tough to do realiably.

And no, very very few of us run turbonetics turbos. There's far too many other great choices out there for us.


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TurboDave & Kathy Huinker, mailto:[email protected][email protected]</A>
TurboD Racing
Lone Rock, WI
86 GN[email protected](MM/MAF Xlator/Extender,MM BstC Boost Command,THDP,PTE44,CAS V2FM,MSD50's,9.5"vigilante 3500)
87 GN [email protected](Stock)
84 Z28 L69
01 Excursion LTD TTS"race" chip 7.3L PSD(power stroke diesel) Turbo 4X2
My photo albums
 

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Discussion Starter · #7 ·
so what is involved or makes a stage II block so special?

also...what does it take to get into the 9's daily driven?
 

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My buddy just built a stage II. First time at the track with only 9 psi of boost and a slow 60 foot, he ran a [email protected]

The Stage motor has a beefer bottom end, awesome heads. The heads have 14 bolts compared to 8 on a 231. The stage heads have gigantic intake valves. Everything about a stage motor is trick. My buddy ran 11s flat with zero boost and not revving it to the max. They truly are amazing motors!
 

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I would buy one built as there are a few custom pieces needed for fuel injection and all.

Prolly $15-20K complete.

Not sure who builds them if anyone in Canada.
 

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There sure is someone in Canada that builds them! One of the Stage motors he built runs 7s, so I think he might know what he is doing. All the fast Buick guys know him.
 

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Ends at II, you really don't need to hear about the top secret stage III project.

I'm not a big fan of racing race cars, I like to hear about the Stage II's with A/C in daily drivers. Not too many of them around unfortuately.

Some year I'll get one.


Okay who builds them in the Northland?
 

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Discussion Starter · #15 ·
yeah apparently there are a few GN beats up here in canada...never been a victim of one yet though.....thankfully
 

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Don't worry you will know a Stage II car because you won't see it. Listen for the very strong whistle and watch for the 9" Ford rear you might get a glimpse of that.
 

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Discussion Starter · #18 ·
any of you guys run stage II motors?

i know some supra owners with ford 9" rear ends...puts the power down nicely
 

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Nah Stage II motors are a bit much when running snow tires in the winter.

Stock motor works fine on the street all year round for me.


Daily driver.
 

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Discussion Starter · #20 ·
with the big turbos you guys run...the ones on the 10-9sec cars...what is the turbo lag like? when do you begin to spool and when do you have full boost?
 
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