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.
My 535is Turbo Buildup Thread! - update 11/26//09
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
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- 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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FirstFives Dictator
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I would like to point out that I am able to run 0.030" gap with no spark blowout at 12psi running a MSD wasted spark setup. I know there have been people who have reported blowout at boost lower than this at this gap running the stock ignition system. Now I just need to track down a spare flywheel so I can have it machined so I can just install it when I do my clutch install.
Last edited by Brad D. on Dec 06, 2009 8:29 PM, edited 1 time in total.
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mooseheadm5
- Beamter
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cvillebimmer
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I was blowing out spark at 9psi with a stock coil. I put in an MSD and no more blowout.turbodan wrote:If you're running a stock gap I guess thats possible. Could be a lot of other things too.mooseheadm5 wrote:cvillebimmer was getting spark blowout at something like 10psi, but he had other tuning issues, too.
Soon after the switch to MSD, I discovered that I was one tooth retarded in my cam timing. I'm not well versed enough to provide an intelligent reason, but my hunch is that with proper cam timing and a stock coil I wouldn't have had blowout with the stock coil.
I dont remember the gap I was using at the time, but I was running over 20 psi with the stock coil back in '07. I want to say .025" but I dont think that would have been possible. I expected to be able to increase the plug gap with the MSD CDI, but I was disappointed to find I could go no larger than I was already with the stock components.
I came to the conclusion that the MSD may be able to produce more spark energy, but the stock ignition components weren't able to handle the higher voltage and would arc if you started to really push it. I'm still running the MSD because it takes the load off of the coil driver in MS, but I dont think I'd bother with it if I were to do it over again.
Blowout at 9 psi is pretty bad. I dont even think I had to gap down the plugs at that boost level. Something definitely wasn't right there.
I came to the conclusion that the MSD may be able to produce more spark energy, but the stock ignition components weren't able to handle the higher voltage and would arc if you started to really push it. I'm still running the MSD because it takes the load off of the coil driver in MS, but I dont think I'd bother with it if I were to do it over again.
Blowout at 9 psi is pretty bad. I dont even think I had to gap down the plugs at that boost level. Something definitely wasn't right there.
i know this is kinda old but i was reading up...
Anyway my little story for over a month i was running bkr6e-11's with no blow out at 7.5 psi and gm wasted coil setup, and no blow out. I was running this til i realized i didnt grab -8's i had grabbed 11's and that is when i changed them after i realized that the -11 meant .040 gap not the .032 gap i thought i had grabbed. I almost want to put them back as the car was running stronger with the bigger gap. I just feared as they wore they would slowly degrade and then i would get spark blow out. or run too hot.
Anyway my little story for over a month i was running bkr6e-11's with no blow out at 7.5 psi and gm wasted coil setup, and no blow out. I was running this til i realized i didnt grab -8's i had grabbed 11's and that is when i changed them after i realized that the -11 meant .040 gap not the .032 gap i thought i had grabbed. I almost want to put them back as the car was running stronger with the bigger gap. I just feared as they wore they would slowly degrade and then i would get spark blow out. or run too hot.
Re: a
Thanks. If you haven't already I would read through the turbo FAQ and the Megasquirt FAQ. If you don't find answers to your specific questions, feel free to ask for clarification.slow5 wrote:your car looks awsome, its comin out good... im turboing mine and i was lookin for advice on fuel management
thanks
also i was wondering how you ran the iacv, and i really like your collector piece yo made and was wondering if you would be interested in makin me one obviously if i paid you haha i just think yours came out awsome and i like the position that it puts the turbo....
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e30-m30_kid89
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do the math, we know your capable. haha i believe he is still using the 42lb'ers and running 8 - 10 psi. Still hasnt done his clutch last i heard.
Not that this is definitive or really helping but looking back on a previous data log the most i hit was 58% with 62lb'ers but with a 2.5 bar reg(makes them closer to 58lb'ers) and 10lbs of boost.
Not that this is definitive or really helping but looking back on a previous data log the most i hit was 58% with 62lb'ers but with a 2.5 bar reg(makes them closer to 58lb'ers) and 10lbs of boost.
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e30-m30_kid89
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Nice, where did you get your injectors from? I'm tempted to just get a set of 55-63lb injectors from racetronix and be done with it, plus new parts are always a plus!bornagain wrote:do the math, we know your capable. haha i believe he is still using the 42lb'ers and running 8 - 10 psi. Still hasnt done his clutch last i heard.
Not that this is definitive or really helping but looking back on a previous data log the most i hit was 58% with 62lb'ers but with a 2.5 bar reg(makes them closer to 58lb'ers) and 10lbs of boost.
i got them through my friends shop and they are 62lb/hr high imp, and i think i paid about 60$ each but that was with a good deal.... and im in canada with you, so it was nice not to have to deal with shipping and duties and all that fun jazz. If you would like i can find out how much for a set and shipping and send some to you. Ohh and they are accel which are a seimens injector and are direct plug and play.
That is correct. My lazy butt (more like way too busy) still hasn't done the clutch yet but have been daily driving the car at 12 psi. I am almost at 80%DC on the 42lbers at 6400rpm. I am totally comfortable running them to over 90% which means I have a bit of headroom left in them. I could also raise the fuel pressure to gain a bit more flow. For now though they are supplying enough fuel to keep the party fun.
You're running severely rich on that log. You would do well to lean it out to 12.5:1. The engine would also be easier to tune with smaller injectors. If you weren't drowning it with fuel you'd be using less than half of those 62lb'ers. 42lb'ers would probably be better for you.bornagain wrote:do the math, we know your capable. haha i believe he is still using the 42lb'ers and running 8 - 10 psi. Still hasnt done his clutch last i heard.
Not that this is definitive or really helping but looking back on a previous data log the most i hit was 58% with 62lb'ers but with a 2.5 bar reg(makes them closer to 58lb'ers) and 10lbs of boost.
It also looks like you've got some enrichments kicking in under boost. Your PW and DC shouldn't have those dips. It'll be a lot smoother under boost if you get that worked out, and it'll be a lot less likely to suddenly detonate for no reason.
This is what you want everything to look like, nice and smooth:
I agree. Higher pressure also yields better atomization as you already know, which is beneficial in several ways, compared to a lower pressure.turbodan wrote:I prefer to run smaller injectors at a higher pressure than larger injectors at reduced pressure.Big Bronze Rim wrote:I could also raise the fuel pressure to gain a bit more flow. For now though they are supplying enough fuel to keep the party fun.
well the injectors were for the big picture which i have not gotten to just yet but am getting there. As for the enrichments, i was having alot of problems with noise in the wiring, that is why i have a brand new 12' foot diyautotune wiring harness with all new connectors. I have a few other plans, including new fuel pump and new regulator running atleast a 3 bar reg. And it is just richening up at the high end which i knew about but couldnt change as my friend had borrowed my tuning cable and i dont run the car that hard very often.