4 speed gear box ???

[flaboy]

i beat on it pretty hard at Moroso this weekend and still struggled to get over 5300 in 4th.

pulled ok to 6800 or so in 3rd.


i was fairly comptative with other cars in my class this weekend.pretty much equal to another ITC rabitt with same box in it.

I am beginning to think it may be a weak motor.

Tim

[msogren]

Check the compression and leakdown. If it is under 150 you will run at the back. Might also check timing, often it is too far advanced. Much over 32* might slow it down, IMHO.
check the cam timing quick by finding a true TDC mark and making sure that both lifters are evenly depressed at TDC. You can get pretty close with a caliper as a depth guage, pretty close by eye , after a few times. The TDC mark is in the book, and often not the timing mark, dont get them mixed up. Most of the time it is 10-11mm before the clutch cover bolt. Use a degree wheel to get it right, if you are going to move it.

FWIW I have never had a gear set checked, or compression checked, or cam checked. Most of the ITB cars have the same gear sets from the sound of things and we all shift pretty much at the same spot.Except the 4.22 cars, they are one gear higher and get draft passed some times. But they are fast also. 4.66 is a lot of gear, that works out to be about 105 mph race car .
They all said that I had too much cam on Sat pm. but none put up 100$ to take my bet. my mixture was too rich for the afternoon heat and idled rough. The cam was(still is) untouched VW, set ahead a couple .
I know at ARRC that stuff gets taken apart. Hey, a Mustang ran near or on my times(2:44 sebring) last time out at 2650# ?? I dont think so legally, Maybe tho. It was colder and good for one second probably.
MM

[JamesB]

Funny you mention final drives. I for one can support that a 3.67 SUCKS at summit point. If your running anywhere near competitve lap times your stuck with hitting fuel cut in the worst places.

On my list for next winter is at least a 3.94 final and a diff (as much as dont mind the welded diff, I hate moving around the paddock. I think at that point I will have good shift points. But I did find how to pick up about a half second with turn5 and getting down to 2nd gear just up till I get to 6a with a shift, tap and turn and im much faster out of there and hitting 4th before turn 8.

[msogren]

The 3.9 works well at Summit. I love the welded but it is a lot harder to drive. You have to enter the turn on power. Or the car goes straight.
But the results are worth it, about 3sec at sebring,
after you retrim the car with less rear bar and spring. MM

[JamesB]

I never had that problem, but given its a momentum car i am on the throttle from the moment I turn in through the corner. Diff or welded thats how I been driving cars at summit point.