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Discussion Starter · #1 ·
Hey im from wisconsin and have to admit to never seeing an opel gt except on the net, but as soon as i did i became obsesed with it......except the engine. I know that u can fit an ls1 in a miata so its gotta be possible to put some v8 in an opel gt right? I was thinking about using a ford ho engine because of its small size. There is one other thing i have been browsing these forums and noticed someone said that they can only handle 180hp without getting to a dangerous twisting point, and i was just wondering if it would be farly simple to just beef up the frame or somthing?
 

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The old saying is "speed is money, how fast do you want to go?"
 

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Discussion Starter · #4 ·
I also want to point out that it dosnt have to be a v8 it could be hampster on steroids for all i care but I would like around 250 to 300 hp or if someone talks me into it more. I would like a 1/4 mile around 12 or better, but im not familiar with the cars specs so i may need more hp.
 

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Über Genius
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OK, here's the scoop on going to a bigger motor.
You will need to beef up the frame so it doesn't twist. This isn't so hard as you will have to do some cutting anyhow. You can either have a frame made and slip on the GT body or start snaking tubular steel throughout the car.
Then there's the suspension issues. The stock suspension will NEVER handle a V-8 you will need a whole new setup for this. Custom fabrication is the easiest way to go.
BUT....
If you are only trying to get into a 12 sec 1/4 mile. I would suggest a V-6 out of a RWD GM. They will fit under the hood with a minimum loss of leg space. (you will lose any future at a heater though) You should be easily able to coax out 180 HP. This is plenty considering the engine and tranny weigh a little less than a gutted Opel GT. You will have to mount your battery under the back deck though as you need to mount the radiator in front of the cross support in the front. I believe the master cylinder needs relocating too. Beef up the front suspension. Rebuild and narrow a Ford 9" rearend and MAKE IT SOLID. A little custom mending on the engine supports, trans support and driveline and voila' you are closer to 10.5 on your 1/4 if you can keep the back wheels from spinning.
I would suggest a roll cage and the frame strengthening as this car will move. And the first time it gets away from you.... Have health insurance or a will :cool:
 

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You'll need about 235 hp to the wheels to go a mid-12 second 1/4 mile, assuming car and driver weigh in at about 2300 lbs. Depending on your rear axle choice and tranny choice, that's anywhere from 270 to 290 hp at the flywheel. Automatic trannys and larger rear axles (such as a Ford 9") will eat up more hp in the driveline. Stock Opel drivelines (4 speed and 5 speed) eat up between 14-17% of the flywheel hp based on cars I've had dynoed. Big tires and heavier wheels take a few more hp out of the chassis hp....

At that level of hp, 275-300, you'll need some reinforcements and preferably a rollcage to keep the glass intact. You'll either break windows or pop them out of the chassis. More to the point, it's the torque that tears into these cars. A high-rpm turbo 4 cylinder can be run up to a lot higher hp level before the chassis starts to complain, but even a basically stock 350 can really ruin the shell in short order, especially if it wasn't perfectly rust-free to begin with.

Just some things to consider...

Bob
 

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Discussion Starter · #7 ·
thanks for your help on my question, but i didnt realize how extreme i would have to go just to get the car to handle 250hp. Does anyone know of a car that has a frame that could be modifed to have the gt body on it.
 

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The GT has a uni-body...no seperate frame. So there is no existing car frame that you can fit it on. The only true option is a custom built tube frame. This is how uni-bodied cars are made into real race cars.
Yes, it can be done...yes it's expensive.
Jc
 

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Check out the following website - http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&access=&mode=tlist&source=&subject=36&thread=

The guys at this bulletin board are stuffing V-6's and V-8's in MG's and are a wealth of information on what engine/trannys to use, cooling problems, etc. etc. The engine du jour is the 5.0 L Ford, but many use the Buick/Rover 3.5 V-8 because of the weight benefits of an all aluminum engine.

http://www.killerbv6.com/homepage.html is a good website for V-6 conversions.

Good luck.
 

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Also be sure to check RacingJunk.com ...at any given time, they seem to have a handful of drag-modified Opel GTs in various stages of completion:

http://racingjunk.com/search.jsp?search_string=opel&category_id=0

I think it would be a lot easier to take an ex-drag car and make it street legal than to fit a V-8 into a GT starting from scratch. It's my plan to "rescue" one of these ex-drag cars myself sometime in the distant future when time and money allows.

-StephenM
 

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Yep, your right, jlthunder. That is a pretty piece, a true motor on wheels! Wonder how much tunnel and firewall was lost to a-commie-date it :p ? I prefer gas-milage over brute-power now, but, when I was younger (18-ish), that would be the toy.
 

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Old Hippe; notice what "geek" said about the windshield. I think the torque from the V8 cracked it. :(
 

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Yes indeedy. Someone did not have the benifit of this site (and our resident experts) to understand the dynamics involved.
 
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