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Kick a little asphalt
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Discussion Starter · #1 ·
Here is a photo of my 2.4 Manta at Pocono this past weekend. The car performed VERY well. It was undoubtedly the quickest car through the turns. The engine pulled very hard off the corners and all the way down the long straight. I had almost four hours of track time over the weekend with no failures. I will post more photos in my album in the photo gallery later. I hope you enjoy them.

Duane
 

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Kick a little asphalt
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Discussion Starter · #2 ·
Here is another shot where you can see how flat the car corners.
 

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Pretty Cool !!!

Is this a race only Manta? or is it street drivable? Us fellow Manta owners would appreciate it it you'd share some of the specifics about the modifications to your car.... Pretty Please!!!

Paul Crane
75 Manta, Original Owner
 

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Kick a little asphalt
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Discussion Starter · #5 ·
It is street legal and I drive it almost daily on nice days. It is a 1971 Manta with 34,000 original miles. I have had 28 Opels over the years, mostly Manta's and Ascona's, and this is the cleanest body car I have ever seen. Never any rust and wonderful trim. I spent almost five years building this one, primarily due to financial limits.

It has a 2.4 with a fully ported cylinder head and twin 45mm Weber sidedraft carbs. I had extensive work done to the valve train including titanium valve spring retainers and platforms for the dual springs. The cam is a 244 @ .50 intake and 234 @ .50 exhaust and uses solid lifters. It uses a 3 quart accusump, an MSD ignition, 2.5" exhaust with straight through mufflers and a custom made cold air intake system that draws air through the headlamp opening. I also run a 8.5 pound aluminum flywheel with an S-10 clutch set up. The engine is mated to a Getrag 5 speed transmission and a ZF limited slip differential with 3:67 gears.
 

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Kick a little asphalt
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Discussion Starter · #6 ·
The chassis has been lowered 3 inches and uses stiff coil springs. It has larger sway bars, all urethane bushings, adjustable shocks and a custom made adjustable panhard bar. The wheels are stock 1971 Manta wheels that have been widened to 8.5" rear and 7.5" front. It runs 235/50/13 rear and 215/50/13 front for tires. I use a urethane replacement for the steering rag joint and will be adding a quick ratio steering rack soon. All urethane bushings have been fitted with grease fittings. The lower control arms have been boxed for added strength.

The interior has a full roll bar, MOMO racing seats with custom aluminum mounts and five point harnesses. It's equipped with a remote fire system, full mechanical gauges and a BWA wheel. All of the sound deadening material has been removed, 43 pounds worth. I also installed a master power cut off switch and a track temp gauge that constantly monitors the track surface temp.
 

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Kick a little asphalt
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Discussion Starter · #7 ·
It also has aluminum pedals and a halmeter to constantly monitor the air/fuel ratio. I moved the speedometer to the right side opening normally reserved for the tach on a rallye. I fitted a 5 inch VDO tach with built in memory and shift light into the center opening where the speedo was. I utilized the gauge mount from a rallye with A/C which mounts on the left side of the dash next to the door and mounts three gauges vertically. I have mounted a digital lap timer to the steering wheel that can be reset at each lap without removing your hands from the wheel. Manual overide switch for the electric cooling fan was also fitted as well as an ignition panel with safety switch and push button starter switch.

I have left the body stock as I find it much more attractive that way. I don't like the flared quarter panels and air dams or rear spoilers. The car has great lines and all that stuff just ruins them.

I hope that's enough details to hold you over for awhile.

Duane
 

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I might add that I have known Duane from phone conversations since 1984 or so. Everything he does is top-notch stuff, no 'butcher' work. Very nice job Duane!

Bob
 

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Kick a little asphalt
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Discussion Starter · #9 ·
While we're exchanging compliments, Bob deserves some of the credit for this car. Especially for the suspension modifications. I may have done the all the work, but Bob was the one who told me what combination of parts would work best for what I wanted to achieve. He has been an invaluable source of information and parts for me since 1984. This car, or any of my previous cars, would not be what it is without him. So, Thank you Bob!

Duane
 

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You're very welcome Duane. Seeing the car in person (Carlisle) and hearing about you stomping on cars costing 4-5 times more makes it all worthwhile.....

Bob
 

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Racing Class

Duane

What class do you race in with all these Mods? Has the engine been dyno'ed? How many HP does your 2.4 make?

Keep up the good work! I'd hope information about your engine and its available power will entice a few to go the route of modifying a CIH engine vs V6/V8 engine swap!!!

Thanks
Paul
 

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Kick a little asphalt
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Discussion Starter · #12 · (Edited)
It will compete in hillclimb, autocross and club road racing events as well as driving schools. Depending on the type of event, it will be classed a little differently. In most cases it will be in a modified class, mainly due to the engine swap. I have not dyno tested it yet as I just got it running last week. I will wait until the engine loosens up a bit before having it tested. I am sure it has somewhere close to 185 horsepower. More importantly, it makes gobs of torque. I believe torque is more important than horse power, especially for street use and the type of events I will run in. High horsepower is good for long road courses, but torque is what you need to pull hard off the corners. The light flywheel is also an important asset as it allows the engine to rev much quicker and greatly improves throttle response.

I would surely advise anyone who wants more power to achieve it through the use of an Opel engine as opposed to a V6 or V8 as it will not upset the balance of the car.

Duane
 
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