Try lowering the tire pressure to 25psi it should help a little.
My 535is Turbo Buildup Thread! - update 11/26//09
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Good & Tight
- Posts: 461
- Joined: Oct 29, 2007 11:16 AM
I have another observation that is worth noting. The diff loads the engine differently and spools the turbo much sooner. In 4th gear, almost 500 rpm sooner. In 5th it's almost 800rpm sooner. This has led to me having to retune a portion of my fuel map as there was never any boost in that area before. It's definitely a problem I can deal with.
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e30-m30_kid89
- Posts: 436
- Joined: Oct 20, 2008 1:17 PM
- Location: Toronto, ON
Great to hear you like the 3.25 and don't regret swapping out the 3.73...We both have very similar goals in power (i'm aiming for 350whp+ @ 1bar) and thinking of out swapping out my 3.73 but damn otis and hes evo-rapeing e30 make me think twice. In all the turbo glory i forget that i built my e30 to be a track/street car which makes it tough to drop the 3.73. Maybe if i just cant put down the power coming out of turns i'll go lower but i'll give the 3.73 a whirl and report back.
It depends what you are trying to do with the car. There is a lot of personal preference and what the car is doing, Otis seems to enjoy his highway pulls, which i'm sure a 3.73 would be great at since traction isn't a major concern. Dan is running a what 2.95? Which I would assume is great for getting all the power down possible, which is great for drag racing. So you go somewhere in between, also the 3.25lsd isn't hard to get your hands on.
For low boost its a matter of preference. I liked the 3.46 when the car still hooked in second gear. It depends on what you like. Once you get used to taller gears you'll probably start to like them more. The difference between a 3.46 and a 3.25 or a 3.25 and a 2.93 isn't very significant. A 3.73 to a 3.25 is significant.
In my experience, the taller gearing helps at all speeds. You still wont hook in first or second, but you have enough time to shift and retain momentum. Third fourth and fifth will pull at least as hard because the engine spends more time under load in each gear. You'll build more boost and accelerate at least as quickly and for longer than you did with shorter gears. I enjoy winding it out and watching my victims suddenly drop further and further back with each shift. I only have two shifts to hit 120. If you have the power to pull it, tall gears are great.
The only downside in wide ratios is gear selection from a roll, but since you're going to blow the tires off below highway speed anyway its not really important.
In my experience, the taller gearing helps at all speeds. You still wont hook in first or second, but you have enough time to shift and retain momentum. Third fourth and fifth will pull at least as hard because the engine spends more time under load in each gear. You'll build more boost and accelerate at least as quickly and for longer than you did with shorter gears. I enjoy winding it out and watching my victims suddenly drop further and further back with each shift. I only have two shifts to hit 120. If you have the power to pull it, tall gears are great.
The only downside in wide ratios is gear selection from a roll, but since you're going to blow the tires off below highway speed anyway its not really important.
Well, I got a little bit of tuning done tonight on the way home. The lower boost onset region is finished and I am almost tuned to 11psi (was at 8.5). It definitely feels a lot better now and the turbo is really coming alive and it feels like it complements the diff nicely. It should be dry out tomorrow ( I found the rev limiter a couple of times) and I'll try to get it fully tuned at 11-12 psi. The amazing part is that the clutch hasn't flared yet, but if it does, I don't really care.
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cvillebimmer
- Posts: 2043
- Joined: May 29, 2008 2:25 PM
- Location: Charlottesville, VA
It's the miracle clutch!
I've been considering dropping the e32 down from a 3.64 lsd to a 3.46 or 3.25 to get more out of first and second gears. Maybe it's just the extra weight of the e32 compared to the e28, but I can already tell there is no way I'm lighting up tires in 2nd or 3rd gear. The car stays firmly planted to the road and pulls like a train. That said, I haven't given my new TCD clutch any real exercise yet either. It's been about 500 miles now on the new block, so the car will get fresh oil this weekend. I need to put another 1,500 or so on it before I really start beating on it.
I've been considering dropping the e32 down from a 3.64 lsd to a 3.46 or 3.25 to get more out of first and second gears. Maybe it's just the extra weight of the e32 compared to the e28, but I can already tell there is no way I'm lighting up tires in 2nd or 3rd gear. The car stays firmly planted to the road and pulls like a train. That said, I haven't given my new TCD clutch any real exercise yet either. It's been about 500 miles now on the new block, so the car will get fresh oil this weekend. I need to put another 1,500 or so on it before I really start beating on it.
Road trip time, to come watch Peter and I autocross.cvillebimmer wrote:It's the miracle clutch!
I've been considering dropping the e32 down from a 3.64 lsd to a 3.46 or 3.25 to get more out of first and second gears. Maybe it's just the extra weight of the e32 compared to the e28, but I can already tell there is no way I'm lighting up tires in 2nd or 3rd gear. The car stays firmly planted to the road and pulls like a train. That said, I haven't given my new TCD clutch any real exercise yet either. It's been about 500 miles now on the new block, so the car will get fresh oil this weekend. I need to put another 1,500 or so on it before I really start beating on it.
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cvillebimmer
- Posts: 2043
- Joined: May 29, 2008 2:25 PM
- Location: Charlottesville, VA
The car is now fully tuned to 12psi, and it feels great. It feels really fast and pulls awesome on the freeway. The turbo is really starting to come into its efficiency island and hit very hard. The diff is definitely a welcome addition at this boost level. It still spins in second, but not as violently which means better acceleration. And the amazing thing.....the clutch is holding.... 
Have you put it through a fourth gear pull yet? If it'll handle that...Big Bronze Rim wrote:The car is now fully tuned to 12psi, and it feels great. It feels really fast and pulls awesome on the freeway. The turbo is really starting to come into its efficiency island and hit very hard. The diff is definitely a welcome addition at this boost level. It still spins in second, but not as violently which means better acceleration. And the amazing thing.....the clutch is holding....
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