2.73 gearing with 3500 stall/cam?
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2.73 gearing with 3500 stall/cam?
Anyone have personal experience with the above setup? I'm fixing to stall and cam my pile this winter and don't really want to spend the time/money getting new gears right now since I already have plans further down the road to get a 12-bolt once the stocker ***** itself.
I'm mainly curious as to how the car will behave with the crappy 2.73 ratio behind the stall/cam. Car will rarely, if ever, see the track. Just looking to make my DD a little more fun to drive on the street... Don't know if putting a mild cam like the 228r would be a bad idea with the current gearing.
Thanks!
I'm mainly curious as to how the car will behave with the crappy 2.73 ratio behind the stall/cam. Car will rarely, if ever, see the track. Just looking to make my DD a little more fun to drive on the street... Don't know if putting a mild cam like the 228r would be a bad idea with the current gearing.
Thanks!
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Thanks for the prompt reply!
Never had a stalled vehicle before. When you say loose, do you mean it will still be slipping past the set stall speed, or do you mean it will just be extra loose down low?
Never had a stalled vehicle before. When you say loose, do you mean it will still be slipping past the set stall speed, or do you mean it will just be extra loose down low?
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Whether or not "looseness" will bother you is really a matter of individual perception.
Higher quality converters (such as Yank, PI, etc.) will generally feel tighter at part throttle, at the same rated stall speed, as the cheaper units. Higher STRs will also make a same-stall-speed converter feel tighter at lower rpms as compared to a lower STR version.
Once you have a 3500+ stall in an LS1/4L60E application, there isn't much to gain in terms of track performance by going up to even a 3.73 ratio (maybe about 1 tenth of ET reduction, on average). Most of the gains that you would see from a gear swap are already covered by the optimized stall speed.
The only real advantage to a gear swap at that point is to "tighten" the feel around town. My recommendation in this regard is always the same: Get the stall first, since that's where the BIG gains are (a proper stall speed, even with 2.73s, is worth about twice the gains of a 3.73 swap with the stock stall), and if you find the around town "looseness" to be too much for your liking, you can always do a gear swap later. This is even more accurate in your case, since you plan to swap the entire rear end later (not sure I would ever bother with that for an A4 car that isn't going to see the track, but it's your cash )
Many people find that the street manners of a high quality ~3500 stall feels just fine with stock gears after a couple weeks of driving them. To me, the difference between 3.23s and 2.73s, with a ~3500 stall, is small. The 2.73s are nice to keep if you want best possible highway MPG while still enjoying the acceleration benefits of the higher stall. I always tend to favor stock gears since a swap is costly (unless you do it yourself), might leave you with gear whine that you didn't have before, and the looseness is generally a non-issue to me.
Higher quality converters (such as Yank, PI, etc.) will generally feel tighter at part throttle, at the same rated stall speed, as the cheaper units. Higher STRs will also make a same-stall-speed converter feel tighter at lower rpms as compared to a lower STR version.
Once you have a 3500+ stall in an LS1/4L60E application, there isn't much to gain in terms of track performance by going up to even a 3.73 ratio (maybe about 1 tenth of ET reduction, on average). Most of the gains that you would see from a gear swap are already covered by the optimized stall speed.
The only real advantage to a gear swap at that point is to "tighten" the feel around town. My recommendation in this regard is always the same: Get the stall first, since that's where the BIG gains are (a proper stall speed, even with 2.73s, is worth about twice the gains of a 3.73 swap with the stock stall), and if you find the around town "looseness" to be too much for your liking, you can always do a gear swap later. This is even more accurate in your case, since you plan to swap the entire rear end later (not sure I would ever bother with that for an A4 car that isn't going to see the track, but it's your cash )
Many people find that the street manners of a high quality ~3500 stall feels just fine with stock gears after a couple weeks of driving them. To me, the difference between 3.23s and 2.73s, with a ~3500 stall, is small. The 2.73s are nice to keep if you want best possible highway MPG while still enjoying the acceleration benefits of the higher stall. I always tend to favor stock gears since a swap is costly (unless you do it yourself), might leave you with gear whine that you didn't have before, and the looseness is generally a non-issue to me.
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Excellent reply, RPM. Covered what I wanted to know. I guess I worded my initial post poorly. It WILL be taken to the track once I swap rears and get the tranny built. I just meant that it won't see any track time until I build up the funds to beef up the drivetrain.
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Anyone have personal experience with the above setup? I'm fixing to stall and cam my pile this winter and don't really want to spend the time/money getting new gears right now since I already have plans further down the road to get a 12-bolt once the stocker ***** itself.
I'm mainly curious as to how the car will behave with the crappy 2.73 ratio behind the stall/cam. Car will rarely, if ever, see the track. Just looking to make my DD a little more fun to drive on the street... Don't know if putting a mild cam like the 228r would be a bad idea with the current gearing.
Thanks!
I'm mainly curious as to how the car will behave with the crappy 2.73 ratio behind the stall/cam. Car will rarely, if ever, see the track. Just looking to make my DD a little more fun to drive on the street... Don't know if putting a mild cam like the 228r would be a bad idea with the current gearing.
Thanks!
Camming the setup will only make it better. Gears don't really add up in a cost/benefit perspective but they do make things feel more fun. I'd go ahead with the converter and the 2.73's!
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2.73 gears and 3500 stall is my exact setup and I love it. Talk to Greg at FTI Converters and tell him your concerns. He'll probably recommend his SLRS3391 (the one I have) it is a 3500 stall w/ 2.35 STR.
Camming the setup will only make it better. Gears don't really add up in a cost/benefit perspective but they do make things feel more fun. I'd go ahead with the converter and the 2.73's!
Camming the setup will only make it better. Gears don't really add up in a cost/benefit perspective but they do make things feel more fun. I'd go ahead with the converter and the 2.73's!
How does the 1-2 shift feel with your setup? Does the stall eliminate that horrible dead zone right after the shift?
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Originally Posted by Microtech82
Does the stall eliminate that horrible dead zone right after the shift?
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I'm confused as to what, exactly, this shift extension is that you guys are referring to. I tried a search and the results just kind of left me scratching my head... If I read it correctly, basically after a shift the stall will continue to slip much like a manual shifter who is slowly letting the clutch out? It won't just bite down right away after a shift?
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I'm confused as to what, exactly, this shift extension is that you guys are referring to. I tried a search and the results just kind of left me scratching my head... If I read it correctly, basically after a shift the stall will continue to slip much like a manual shifter who is slowly letting the clutch out? It won't just bite down right away after a shift?
Shift extension is the rpm to which engine speed drops after a WOT upshift, while still at WOT. With a "proper/ideal" stall, engine rpms will never drop out of your powerband once you go WOT. Ideally, as a general rule, you want to upshift right at or just slightly above your peak horsepower, and then have rpms drop no lower than your area of peak torque. This optimized shift extension, combined with the much more explosive launch of a proper stall speed, accounts for why gear ratio changes (within the typical street range) don't do much to improve ET performance once stall speed is optimized. More aggressive gear ratios will improve mechanical advantage, but mechanical advantage becomes less critical once the engine is allowed to quickly reach, and stay within, its powerband (as is the case with a proper stall). The higher stall converter will "slip" the engine to higher rpms for launch and upshifts. You won't really notice any "slipping/looseness" during a WOT upshift, but rather the engine just won't drop to as low of an rpm as it would have with the stock stall.
Last edited by RPM WS6; 12-18-2013 at 02:30 PM.
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Excellent, thanks for the input!
All this talk is getting me really excited...a stall will be my belated Christmas present to myself and I'll finally have some neck-snapping power in the next couple of weeks
The dyno sheets I've seen for the 228r seem to show peak tq around 4k. I was originally going to go with a 3200 stall, but after reading your reply I definitely see how a 3500+ would take better advantage of the cam. I still have about two weeks to make up my mind but I think I'm going to go with a 3600 stall from Yank.
Tuning. There is going to be maybe a month between when I install the converter and when the cam goes in. I will, of course, take it to get dyno-tuned once the cam is in, but can I get away with a simple flash tune for the stall until then? Or will the stall require a dyno tune, as well?
Thanks again for all the input, fellas.
All this talk is getting me really excited...a stall will be my belated Christmas present to myself and I'll finally have some neck-snapping power in the next couple of weeks
The dyno sheets I've seen for the 228r seem to show peak tq around 4k. I was originally going to go with a 3200 stall, but after reading your reply I definitely see how a 3500+ would take better advantage of the cam. I still have about two weeks to make up my mind but I think I'm going to go with a 3600 stall from Yank.
Tuning. There is going to be maybe a month between when I install the converter and when the cam goes in. I will, of course, take it to get dyno-tuned once the cam is in, but can I get away with a simple flash tune for the stall until then? Or will the stall require a dyno tune, as well?
Thanks again for all the input, fellas.
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Tuning. There is going to be maybe a month between when I install the converter and when the cam goes in. I will, of course, take it to get dyno-tuned once the cam is in, but can I get away with a simple flash tune for the stall until then? Or will the stall require a dyno tune, as well?
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As I've never had a stalled vehicle before, I'm apprehensive about going as high as a 4k stall. Some people say it's too much for a DD, others say it's fine. At first I only wanted a stall just so I could cam the car, and planned on a really small stall (just enough to avoid idle issues). Then, after I had done more research and set my heart on the 228r, our local GM tuner strongly advised me not to go any lower than a 3200 with that cam. Now I'm thinking a 3600 would better compliment the 228r while still retaining good street manners for my daily commute, ie not being the obnoxious shmuck spinning the motor to the moon just to hang with traffic from a light. I think I'll stick with the 3600 for now and see for myself how it feels. If I end up wishing I had a higher stall I can restall it.