mfoley Posted December 24, 2004 Share Posted December 24, 2004 I could use a little help. I'd like to get a limited slip trans with short 5th gears. I'm looking at used ones but I'm not sure which models had what I'm looking for. Here's some questions I have: 1. Are all 924S transmissions Limited Slip w/short 5th gears? 2. Do all 1988 944 transmissions have short 5th gears. Limited slip must have been an option in '88. Thanks, Quote Link to comment Share on other sites More sharing options...
greg f Posted December 24, 2004 Share Posted December 24, 2004 Very few 924S gearboxes will have LSD in them as it was an entry level car. Only the 944S models and the 924S models have the .829 5th gear you need. The gear is still available from Porsche for $300 and takes less than 30 minutes to change once the box is out. The lsd transmissions are identified on the top of the case with a two digit code. 944 codes 85.5 8Q 86 5Z 87 7V 88 5Z 89 ASH 924S codes 86 7Q 87 7Q 88 7Q Hope this is helpful, Greg Fordahl Quote Link to comment Share on other sites More sharing options...
Tim Comeau Posted December 24, 2004 Share Posted December 24, 2004 Greg, I think you meant 88 944, and not 944S? You can get the short 5th in the 88 944 and any of the 924S's. Came stock in those models. I believe the 951 gear boxes have the same 5th gear pair as well as some Audi model. I can never remember which dang model.....100 LS? Fox? Same exact part so the source doesn't matter. The cheaper, the better. Quote Link to comment Share on other sites More sharing options...
greg f Posted December 24, 2004 Share Posted December 24, 2004 No, the 88 2.5l 944 has a .7 5th gear, not the .8 from the two S cars. The 944S has just slightly different gear ratios than the 944, and the shorter 5th due to the percieved lack of torque. I think the 944S box is the best geared for track use, but it is extremely close to the normal car. The 951 has completely different gears because of the 9:31 R&P ratio, not very useful for a N/A car. Most Audi gearboxes can be used as donors. The Audi Fox will provide a nice 4:10 final drive. A VW Quantum will yield a 4:30. Audi 5000's have some interesting alternate ratios. The Audi V-8 cars have steel syncro's that are very useful for 2nd and 3rd gears for us. ( places like Portland with a chicane can be hard on these syncro's.) Greg F Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted December 24, 2004 Share Posted December 24, 2004 Greg... Everything i have seen says the 88 944 has the .829 5th gear ratio. I do know 100% that the 87 and 88 924S has the .829 5th gear I have 88 Turbo S so I can dig into the 88 factory manual and check gear ratio numbers from 88 944. From my numbers that I have gather from various sources Car........944 83-87.......924S/88&89 944.....944S......... 951 R&P........3.889..............3.889.....................3.889.........3.375 1st ........3.600..............3.600.....................3.500.........3.500 2nd........2.125..............2.125.....................2.059.........2.059 3rd.........1.458..............1.458.....................1.400.........1.400 4th.........1.071..............1.071.....................1.034.........1.034 5th.........0.730..............0.829.....................0.829.........0.829 I will attempt to validate that the 88 944 had the 0.829 ratio. So for these cars the 944S is slight taller geared in ratio 1-4 and same in ratio 5 as the the 924S. R&P is also the same ratio. The 951 and 944S are the same except for the R&P Ratio. In either case the 5th gear alone is the same 0.829 ratio we are looking for. Quote Link to comment Share on other sites More sharing options...
944-Spec#94 Posted December 24, 2004 Share Posted December 24, 2004 Well here is proof. Notice a few things 016K/016J are 944 gearboxes. 083D is from the 944S. In parenthesis at it notes .729 for 5th gear for US car and .829 for Euro cars. It also states that in 88 all cars came with the same .829 ratio. Makes sense since 88 was the first year the euro car and US cars had the same motor. Quote Link to comment Share on other sites More sharing options...
Tim Comeau Posted December 24, 2004 Share Posted December 24, 2004 Ok, good. We're posting some good info here for all the guys. Greg, Have you ever built a trick, close ratio gearbox for the NA 944's? I've wondered what that would do for our little 944's if we run in a different POC class just for fun. Might surprise a few people. Quote Link to comment Share on other sites More sharing options...
greg f Posted December 24, 2004 Share Posted December 24, 2004 Well I'll be dipped in..... I just looked it up and saw that you are indeed correct, it appears the 88 cars were WW ( Worldwide ) and so would have the Euro ratio's. Now if I could just find a wrecked 88 up here.... I have one guy that decided to race his 87 944 in RS. We rebuilt the engine with a production spec head, a Linsey intake manifold from a 951 and a programable mass flow and acheived 186 RWHP at 6800rpm. He has a trans that uses some alternate ratios as well as the 4:10 final drive. The car runs 17" wheels with 245/40-17 Hoosiers. It is pretty quick and the gear ratios are nice to drive without the big splits from 3-4 and 4-5. Greg F Quote Link to comment Share on other sites More sharing options...
mfoley Posted December 24, 2004 Author Share Posted December 24, 2004 Thanks guys. I thought I had an '88 with lsd but they rechecked it and it wasn't lsd, so I may go with the gears now and get the lsd later. If I buy new do I need one gear or two gears? Quote Link to comment Share on other sites More sharing options...
Tim Comeau Posted December 24, 2004 Share Posted December 24, 2004 Mark, a "gear ratio" is always going to be 2 gears. 1 on the input shaft and 1 on the pinion shaft. So your short fifth gear ratio is actually 2 pieces of round metal with teeth. Quote Link to comment Share on other sites More sharing options...
mfoley Posted December 24, 2004 Author Share Posted December 24, 2004 ... I knew that . Thanks Tim. Quote Link to comment Share on other sites More sharing options...
uberklasse Posted December 25, 2004 Share Posted December 25, 2004 I need to chime in because I just went through this whole ordeal last weekend. I found an '88 tranny with factory lsd...rebuilt! It was too pricey for me....anyone want to guess how much? Dylan, Eric, you guys already know what the guy wanted! Quote Link to comment Share on other sites More sharing options...
Tim Comeau Posted December 25, 2004 Share Posted December 25, 2004 one hundred million dollars......... Quote Link to comment Share on other sites More sharing options...
mfoley Posted December 27, 2004 Author Share Posted December 27, 2004 and the answer is ... Quote Link to comment Share on other sites More sharing options...
uberklasse Posted December 29, 2004 Share Posted December 29, 2004 $2,500 Quote Link to comment Share on other sites More sharing options...
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