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Discussion Starter #1 (Edited)
Introduction: I have been reading everything on this web site that I can get my head wrapped around for two years now. In order to build our Lemons race car to perform well I have used just about everything on here that is within my capability set. Thank you everyone for sharing your ideas. I will try to reference the post I got them from.

State of the car: This is a Lemons car and some of the things I have done are not possible for a daily driver. Also the car was pretty rotten when we started. I do not think it could have (or would have) been restored by anyone.

List of the modifications:
Ported and welded intake manifold
Exhaust manifold modified into sprint style with divider
Weber 38 carburetor on top of derlin spacer, cable operated
Side exit exhaust with 2" glass pack
Welded front upper A arms
New front suspension bushings
Front suspension shackles for 2" drop
Cut rear springs for 2" drop
Four wheel disc brakes with proportioning valve
New KYB shocks
Adjustable rear panhard bar
Welded rear differential
Solid spacer replacing crush sleeve in rear end
Heavy duty toque tube donut
OGTS sway bars front and rear
Shock tower connecting bar welded across engine bay
Roll cage connected to front shock towers and door jams
15" wheels and 205 wide rubber using wheel spacers
Fuel cell and big honkin fuel filter
Completely new wiring
Racing seat
Uprated alternator (not installed yet)
Pertronix unit and flame thrower coil (not installed yet)
Additional cooling (not complete)
Extended headroom
Fender mounted mirrors... truck mirrors :yup:
 

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Discussion Starter #2
Intake work

I ported my intake following the practices used by Rallybob. His article and thread are all anyone should need to do the work. I did not get crazy with the grinder. Probably could have done more, but did not want to damage anything. My team mate did the welding.

Threads:
http://www.opelgt.com/forums/opel-engine-performance-modifications/20448-new-intake-manifold-modifications.html

http://www.opelgt.com/forums/opel-engine-performance-modifications/2847-porting-intake.html

Article: on the Hemmings Opel club site
http://clubs.hemmings.com/oana/tech/Intake.pdf

Steps taken:
1. Scrape crud off.
2. Dip in de-greaser to get the rest of the crud off. (repeat a few times)
3. Mount to a rigid stand to prevent flexing, use intake as template.
4. Cut base off smooth with runner bottoms.
5. Cut second steeper angle in middle and fit some angle aluminum to your cuts.
6. Get to grinding. I just added some taper to the runners and plenum area.
7. Weld on lower cover. (after all grinding dust has been removed)
8. Carburetor spacer cut to match bottom of Weber 38 and tapered toward intake opening.
9. Fit to engine (test fit actually)
10. Make small brackets to adapt motorcycle clutch cable to throttle pedal lever arm and carburetor.
11. Bracket that goes to carburetor throttle re-worked to fit around fittings.
12. All installed.
 

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Discussion Starter #4
Side exit exhaust

I cut up our stock exhaust manifold to make it into a sprint style manifold. I included a center divider for the two and three cylinders. The most questionable part of this whole deal is that I brazed it together. We will see if it holds up or not.

Steps:
1. Cut off intake chimney and grind to make appropriate runner volume when capped.
2. Cut 2/3 runner divider and fit. (lots of grinding and checking)
3. Stop divider where the runner area gets smaller to try and maintain flow.
4. Shape cap.
5. Shape cap.
6. Braze the inside divider as far as possible then braze on cap.

Note: I am not very experienced at brazing so I went with the more is better theory. When done I checked the inside and could see that a lot of it had weeped inside following the hot metal which tells me the steel and iron were hot enough.
 

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Discussion Starter #5
Exhaust continued.

Steps:
7. When i fit the exhaust and intake and snugged the bolts down the exhaust cracked. I pulled it and looked inside. I had ground the wall too thin there.
8. I brushed the area clean and put the whole exhaust on top of my chiminea and let it get good and hot.
9. Then I brazed it again.

After this repair it has been installed and taken up to temp a few times and survived. It has not been raced yet.

The paint on it is high temp exhaust paint. After a day on the chiminea and heat from the torch the areas that I did not brush off seemed perfectly fine.
 

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Discussion Starter #6
Exhaust continued.

Steps:
10. Making a merge collector.
11. As smooth and interior as I can make.
12. Adding angle pieces to the end so it will mate up to square cuts.
13. Whole thing welded together.
14. I cut the webs off of the exhaust runners.
15. All brushed and cleaned up.
 

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Discussion Starter #7 (Edited)
Exhaust continued.

Steps:
16. Final check fit. I capped off some of the passenger foot well for the exhaust.
17. Paint with high temp black exhaust paint.
18. Installed.
19. Installed exterior view.
 

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Discussion Starter #9
Sway bars

I purchased and OGTS front and rear sway bar from another member. It came with everything except the rear axle brackets. Those I made. The install of both front and rear were not too difficult.

Rear brackets were made from 2" x 2" x .125" angle iron and washers with 5/8" id. The id was chosen because that is what the nub on the generic suspension bushings that Pep Boys had. After making the brackets and welding them to the rear axle I cut the bushings down so they would fill the gap between the bracket that came with the bar and my brackets on the axle tubes. I determined length and angle just by looking at other peoples photos. I drilled a hole in my brackets larger than the od of the bolts. The idea is that the compressed bushings inside the washer id is what locates them, not bolt on bracket contact.

Steps:
1. I cut the brackets to look like others I had seen in pics. I used a whole saw with the same diameter as the axle tubes to check fitment. Those washeres were welded to the bracket on both sides.
2. Here the brackets are welded to the axle with 26" center to center distance. They are angled down 25-30° from the torque tube.
3. I welded all the way around, this is at least as sturdy as others I have seen pics of. (hopefully)
4. I cut the generic bushings to fit my gaps.
5. ...or so I thought. I had to do a lot of shaving. This stuff does not cut easily, but it can be done.
6. Rear sway bar installed. The axle is still dropped in this pic. With the wheels, springs in, and car sitting down the sway bar sits right were I want it.
 

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Discussion Starter #10
Front suspension rebuild

We purchased up-rated bushings from OGTS. The whole front end was torn down, sand blasted, painted, and re-assembled. We added two inch dropped shackles. The upper ball joints were moved in to accompodate the drop.

Shackels thread: http://www.opelgt.com/forums/performance-suspension-braking-upgrades/3805-front-spring-lowering-shackle.html

Steps:
1. Remove entire front end as one unit.
2. Front end dis-assembeled.
3. Upper A-arms blasted.
4. Upper A-arms showing welded plates on bottom side. Bushings with grease zerks installed.
5. Partially re-assembled front suspension. Ready for transverse leaf spring.
6. We man handled the spring into place and used c-clamps. A proper spring compressor would have been better.
 

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Discussion Starter #14
Cooling package

In order to aid cooling we added a heater core and an oil cooler. The heater core is a Ford unit I got from Summit Racing. I just looked at the dimensions and the hose outlets until I found one that looked like it would fit my location. The oil cooler is a generic item from Summit as well.

I have no belly pan or head light buckets in the nose of my car so there is a lot of room to work with.

Pics:
1. Design for the oil cooler mount.
2. Lots of space under the nose.
3. Oil cooler bracket with edges to keep the air captive and force it through the cooler.
4. Oil cooler bracket from the bottom.
5. Heat exchanger mounted and ducting started.
 

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Discussion Starter #15
Cooling continued...

Pics:
6. More ducting bracket.
7. Ducting with bottom riveted in.
8. Front view, air in above the board, and through the nostrils, out the hood.
9. Explanation of air flow.
10. Front 3/4 view.
 

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Looking good! Ducting is critical, glad you didn't just stick the cooler down in the grill opening.:yup:
 

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Discussion Starter #17
Weber 38 tuning.

We are running a 38 Weber on a ported intake with a very open exhaust. My entire understanding of tuning a carburetor is from reading this site. The more knowledgeable fellas seem to say try it and adjust from there, so I did.

Three weeks ago I had mains 135's, air 175's, large idle 45, small idle 45, e-tubes F-66's. It only ran like this in my garage while revving the throttle and congratulating myself on putting the car back together. It would run with one idle screw all the way in and the other barely cracked. Probably not right.

After my wife informed me about the gasoline smell in the house I decided to change jets. Next I went to mains 130, air 165, and did not change the idle jets or e-tubes. Much better. Noticeably smoother running and no more gas smell. We did three of five 20 minute track sessions like this. It stumbled off the line and was still a bit rough.

During a gap in sessions I swapped the 165 airs for 175's. This made it very drive-able at low rpm's, smoothed out the idle more, and improved the transition to throttle. It had lost a bit on the top end though.

After the race I put 170 air corrector jets in. I have not had a chance to drive it like this.

Current setup:
Mains 130/130
Air 170/170
Idle 45/45
E-Tubes F-66/F-66
 

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Discussion Starter #18
Note on home made Sprint Exhaust

It works. We completed five 20 minute hot lap sessions at a race track with cooling between rounds and the exhaust held on tight. No leaks. I am quite pleased with this.
 

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Wiring

Our wiring is completely new. We are using stock gauges, and aftermarket fuse block, a 100 amp one wire alternator, and an internal resistance coil. We have not yet installed the Pertronix kit that we have. There is also plenty of room and juice to install lights if necessary.

Pics:
1) Home made gauge panel. It is some delrin that I cut with a jigsaw.
2) The board that I mounted the fuse panel and starting relay to.
3) Connections made
4) Pretty much done. A few more zip ties went on after this.
Pdf's:
1) Home did wiring diagram. I used the same program that Team Tiny Vette suggested (ExpressPCB)
2) Wiring diagram for specific items

Note: Our stock Tach is crap and will be replaced. I have read a lot about potential fixes and it still bounces around.

I modified the lower alternator bracket with JB Weld as suggested in this thread: http://www.opelgt.com/forums/1a-starting-charging-system/248-alternator-headlight-upgrade.html

Team Tiny Vette's wiring thread: http://www.opelgt.com/forums/1d-wiring-diagrams/25860-my-little-wiring-diagrams.html
 

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