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Discussion Starter · #1 ·
my friend has sparked a fire in me to change plans for my gt
not to make a drag race only gt but to build a car for the
Grassroots Motorsports $2004 dollar challenge
i think my gt has a good chance
first off the suspension needs to be addressed
what can be done to the stock suspension to improve times in the autocross competition
i figure sway bars lowering shackles and prob cut springs in the back and racing shocks( if anyone has a set of good used ones let me know )
i will use the 1.9 in the car to build with either high copmpression or flat top pistons
use larger valves in the head and minor porting
also a 150 to 200 hp shot of nitrous
the engine will be setup autocrossing rather than drag but will do good in both(so any good cam grinds or good cams around let me know)
i am debating on whether or not to use the manual or my built auto i am steering towards the auto because i know it will handle the power and it will put the weight a little lower in the car and more period for drag traction
i plan on using my isuzu trooper rearend with 4.10 gears and disc brakes on the car with opel brackets
please critique this idea nad help me out as much as possible with parts or what ever

check out www.grassrootsmotorsports.com to view the rule to helps me
thanks
 

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Code Goober
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243 Posts
If you're planning on using that much nitrous, you're going to need to use direct port injection. A single nozle wet shot that large in the opel manifold would likely cause a small explosion and destroy your carb. There was a web site that I found once that detailed how to build your own direct port nitrous system using parts available from Radio Shack. Do a google search for Nitrous do it yourself and motorcycles (he drag raced motorcycles). Good luck.
 

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903 Posts
> i think my gt has a good chance

good luck. The anti was really raised this last year. The drag times in particular are VERY impressive. RallyBob, myself and a couple others had been working on a car for the last 9 months or so with the intention of winning. We however just decided to abandon the project as our 'likely win' had now become unlikely. Our plan was VERY agressive and would have been to much time to invest to not win.

> first off the suspension needs to be addressed
> what can be done to the stock suspension to improve times in
> the autocross competition
> i figure sway bars lowering shackles and prob cut springs in the
> back and racing shocks( if anyone has a set of good used ones
> let me know )

The suspension will need lots of work. While I don't have my auto-x suspension fully worked out I am definately in the ball park. As I make improvements I'll keep you updated if you continue with this project. Here's the current state.

180lb 2" lower rear springs
RS9000 rear shocks
three link rear(lower links have heim on one end and poly on other, upper link heim on both ends) I have quite a bit of anti-squat
3/4" adjustable rear bar. solid body bushings and heim jointed ends
7/8" manta front bar. solid mounts and heim jointed ends
OGTS 2" lowering spring
Koni yellow front shocks
poly bushings all around
torsen style lsd and 4.88s
very long adjustable panhard bar

> i plan on using my isuzu trooper rearend with 4.10 gears and
> disc

I started with a 4.10 and it didn't work out well with 20" tires. The Opel 4 speed has a giant hole between 2nd and 3rd gear. Much of the course was right between the two gears. Too fast for second and too slow for third. I was constantly shifting trying to find a gear that worked and upsetting the chassis at every shift. Now with the 4.88s I use 2nd to launch and 3rd for most if not all the course. On the larger courses I use 4th occasionally...

TGSI recently made a post about shocks and their affects on transient handling. I rarely hear the road racers talking about this, but this is absolutely key in auto-x. You spend A LOT of your time in transition.

-Travis
 

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grm $2004

hey 72opelguy,

i entered my gt in last years race, but i did'nt get finished in time. it was a huge undertaking. i went with an engine swap. i took a $700 ford thunderbird turbocoupe and swapped the entire driveline in the opel. the engine should be putting out 250-275hp and 300+ftlbs, my final weight is 1900-2100lbs so this car should be very quick. i had to completely fabricate the front suspension because i used the tbird spindles and brakes. i used the t-5 trans and i narrowed the 8.8 disc brake rear end.

i went to the $2003 with no car, i still had a blast. but there was some stiff competition. alot of turbo 4 cylinders cars, the 323 gtx was awesome!! where were alot of dodge turbo's one went in the 11's !! but some people take this thing to far. the mongrels v-8 miata was some bullshit...i saw it in person, and it was over the top, how it was legal? no idea honestly everone else seemed to be about right. there were actually alot of crap ass cars there, they sounded like ass, and ran about the same. they have changed the rules for the better and i have already entered my gt for the $2004 better hurry up and send in your entry, the spots fill up quick!

sorry to here that rb and travis won't be bringing a car...you guys could still do very well or win. i honestly thought my car would have placed to 3 or won... it has a coolness factor that a miata (barbie roadster) doesn't. the caliber of alot of the cars was just not that high. i realized that i had 'overdone' my car, i spent way to much time making everything perfect. i had never seenany of the cars in person so i assumed they were all done well. you can't judge the condition of these cars by a 2"x2" picture in a mag. there were some incrediable cars, but allot were just crap. you guys can do it! i want to see you there!

good luck to all who go for it! see you there!

jon
 

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Discussion Starter · #5 ·
what are the times in autocorss for a midly uild suspension in the gt
just to get a ball park
i am alot better at drag racing so what i cant do in autocross i can make up for in the drag
 
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