My 500HP V6

[sandt38 448]

Well, sine Tirefryr asked, I guess I would post my toy. It is a 1986 Buick Grand National. It has a 3.8L V6, 30 over and stroked. Forged TRW 8.5:1 pistons and a forged Crower crank. Comp cams custom cut to optimize exhaust gas speed to increase spool up and reduce lag. The heads are cast, ported and polished with stainless valves, Chevy 350 lifters and comp cams 1.6:1 roller rockers. The intake manifold is match ported and polished to the heads, and fed through a Turbo-TA stretched intercooler with a Duttwieler neck conversion. I use a 3 inch cold air pipe and a 9 inch K&N. I use stock style headers (I found they have better bottom end then the high flow headers) a TA51 turbo, 2.5" downpipe, catalytic converter delete and Hooker Cat back system. I use a secondary in-line Bosch fuel pump and 120# injectors for fuel. An Art Carr built transmission with a 3500 stall converter. Suspension is pretty much stock, with poly bushings, boxed rear trailing arms, TRW Variable rate rear springs and new TRW front springs. I think that was all that matters under the hood. I put it on the Mustang and dialed in 495HP and 525Lb Ft of torque on 24#s of boost. My best 1/4 is 11.84@119. My 0-60MPH times are 4.2seconds. I inititally swapped out the 3.42 gears out for 3.73s. I figured when i opened up the exhaust my top end would improve and i could put 3.90s in it. So I put 3.90 gears in it but I found I lost too much top end down the quarter, dropping my quarter times and trap speeds. So I went back to 3.73s to get my 1/4 times and trap speeds back up but my 0-60 times fell a bit.

In the trunk is a Ported Adire Brahma (1.9ft tuned to 24Hz), powered by a Cadence Z7000HC (1500X1 class AB). The front stage is a pair of Adire Koda 6.1s powered by a Cadence Q3000. The HU is a Pioneer Premier DEH-P740MP. I have an AC Delco Platinum AGM battery out back and a true isolator out front.

Pics? OK

[altoncustomtech 773]

A thing of beauty. That's some incredible #'s for a 3.8L V6. I've seen a few hot ones around here but none are that hot. Anywhere near 500HP from any V6 isn't playin' around.

[KU40 173]

You've done some serious work there.

[stevemead08 752]

i love grand nationals!!!!!

[jonbearsmt 919]

yummy.....

charlie cruiz>

[cobra93 47]

I'm a ford guy at heart sandt38, but the Grand national's/GNX's are awesome.

BTW, Thanks for all your help so far, Joe.

[sandt38 448]

Thanks guys, I forgot to put the info about the rear end in there and just added it. Also, I forgot to mention, I did everything myself. I worked for a shop where we specialized in GNs, and I bought this for a song. I paid $1500 for it, but it was trashed. My wife shit when she first saw the car. It had gold spoked Daytons on it, it was all oxidized, the motor was gone (I mean absolutely thrashed) and the transmission case was broken.

[Penguin4x4 1,761]

Ohhh, now I remember you

funny how I can know a guy more by his audio install than his face

such is life

[sandt38 448]

I get that all the time. My car is memorable... but alas, I am not

[Tirefryr 1,742]

Love it!!

You mentioned Duttwieler in the Ihop or RTMS and your work with him. I remember him from the early Mustang/GN wars of the early 90s. He made a good amount of power with both platforms. He's currently building modulars for Granatelli Motorsports. That guy really knows his shit.

Are you launching off a brake or footing it?

[Acidburn 10]

way bad ass dude

it's interesting that you're stepping up (numerically) the rear gear ratios. the turbo racers I know around here go lower with their gears to help load up the turbo. thoughts?

[sandt38 448]

Love it!!

You mentioned Duttwieler in the Ihop or RTMS and your work with him. I remember him from the early Mustang/GN wars of the early 90s. He made a good amount of power with both platforms. He's currently building modulars for Granatelli Motorsports. That guy really knows his shit.

Are you launching off a brake or footing it?

Footing it. I know people would disagree but I just don't think a brake belongs on a street car. I can build 7 pounds at the line and just start to blow the tires away. A break seems counterproductive. If I ran with slicks all the time, I could justify it. But i haven't even been to the track in 7 years

way bad ass dude

it's interesting that you're stepping up (numerically) the rear gear ratios. the turbo racers I know around here go lower with their gears to help load up the turbo. thoughts?

You'll have to get me on the same page... a 3.90 is a lower gear then a 3.73.

My car is an auto, as all GNs and TTypes were. With an auto we don't need to spool the turbo while moving, we can build boost on the line. When I put the 3.90s in it my acceleration was significantly harder, and I had better 60 ft times by a good margin. But by the time I got 7/8s of the way down the track I was running out of motor. My times actually dropped almost 3/8 second. With the 3.73s I was able to stay in my powerband to the end of the track. If I were to run 1/8 miles I would have likely gone to 4.10s, but I ran 1/4s. Also, as far as streetability, the 3.73s are much more gentlemanly gears on the road... and this car gets driven. It has ~240,000 on it now.

[Sir-Lancelot 216]

Nice! Get you some black Enkie style rims like the GNX had.

Not sure how old you are, but my for age group that car was the shit in it's day. Ive had everything but, Monte Carlo SS, 442 Olds, but never a GN or a T-Type.

Buddy down the road is building one. Love that car.

[raolito1980 2]

This car is bad. Good job with the car in and out.

[dvalue 17]

GNX's are sick!

Yours is no exception!

[Randal Johnson 544]

Very nice Ride !!!

[Sir-Lancelot 216]

GNX's are sick!

Yours is no exception!

Not a GNX, but still sick.

[NB50 206]

Screw pics, I want videos.

[Julian 641]

i want to get my V6 2011 mustang up to atleast 400hp

Looks great.

[dvalue 17]

GNX's are sick!

Yours is no exception!

Not a GNX, but still sick.

Close enough for me

What are the differences? Guess I need a refresher.

[sandt38 448]

GNX's are sick!

Yours is no exception!

Not a GNX, but still sick.

Close enough for me

What are the differences? Guess I need a refresher.

1 second in a quarter mile...

The GNX can be identified by the black 16 inch aluminum wheels where the GN had stamped 15 inch chromed wheels. Mine has the TType wheels on it, as the GN wheels were very heavy and very ugly. I have a shot of the car when i first got it on the road with those GN wheels, I'll pull it up and post it. They also had the Buick 3 port holes in the front fender.

There were only 547 GNXs made in 1987. The cars gained speed with a special chip, a ceramic impeller turbocharger, a larger intercooler, and a longitudinal torque bar (a support which attaches the transmission directly to the rear end), and a panhard rod. The suspension is markedly better.

I would love to own one. The cheapest I found one that was unmolested was a car with about 90,000 miles on it, and the guy was asking $45,000. I am just too damn cheap to spend that on a car that retailed for under $35,000

[j-roadtatts 1,129]

Sweet car Brother!!! Makes me miss my 76' firebird.

I had a friend with a Monte Carlo with the 454 stuffed under the hood, that thing was nutts.

[sandt38 448]

Sweet car Brother!!! Makes me miss my 76' firebird.

I had a friend with a Monte Carlo with the 454 stuffed under the hood, that thing was nutts.

I love me some big blocks. My favorite car I ever had was a 1970 Olds 442 W-30 ragtop. It had that nasty 455 olds motor in it. It had like 325HP but almost 600LbFt of torque from the factory. When I got done with that car I could only run it on race fuel. I had 12.5:1 compression, a stump puller of a cam, an 1150CFM Holley Dominator on it, and glass packs about 2 feet past the headers which is where the exhaust ended, and 4.11 gears with a 3 speed transmission. I put suicide swivel bucket seats in it. I could pull the front wheels off the ground at 1/2 throttle. Great 1/8 mile car but the thing ran out of gear at about 85MPH. You would ride down the highway doing 65MPH turning 4000RPM. It was so frikken beastly there just aren't words. It was just nasty, nasty loud. You couldn't get a system in that thing and hear it no matter what you did. Sadly I got drunk and wrapped it around a tree.

[Acidburn 10]

way bad ass dude

it's interesting that you're stepping up (numerically) the rear gear ratios. the turbo racers I know around here go lower with their gears to help load up the turbo. thoughts?

You'll have to get me on the same page... a 3.90 is a lower gear then a 3.73.

My car is an auto, as all GNs and TTypes were. With an auto we don't need to spool the turbo while moving, we can build boost on the line. When I put the 3.90s in it my acceleration was significantly harder, and I had better 60 ft times by a good margin. But by the time I got 7/8s of the way down the track I was running out of motor. My times actually dropped almost 3/8 second. With the 3.73s I was able to stay in my powerband to the end of the track. If I were to run 1/8 miles I would have likely gone to 4.10s, but I ran 1/4s. Also, as far as streetability, the 3.73s are much more gentlemanly gears on the road... and this car gets driven. It has ~240,000 on it now.

I was speaking lower numerically, as in shallower. I know a couple guys around here with turbo LS1/auto Camaros, and they first had 3.73s then switched to 3.23s and got faster.

[6APPEAL 7]

Nice build. But 120# injectors? For your build and turbo I would have expected 42.5# up to 60# injectors. Are you on any of the Turbo Buick forums or GSCA? I really have got to get to work on my 87 GN street car. I've been doing a resto-mod for the past 4+ years. It's close to running, it just won't be pretty.

John