Tranny Gaps seem less significant
09-18-2009, 11:55 AM
#1
Three Wheelin'
Thread Starter
Tranny Gaps seem less significant
I have owned my 993 a little over a year now. We I first got the car, I felt that it was a little underpowered so I did some research, and I talked with the experts and the options included:
I had a discussion with Steve Weiner
and we talked about re-gearing the transmission. Steve argues that the car actually has plenty of power for the cars weight (which I agree), but because of the somewhat tall US gearing it difficult to keep the car in the “power band”. I think Steve is right on. There are lots of threads on hear discussing re-gearing to essentially shorter gears. I believe Bill Verberg and other are all over this.
I also had a discussion with ViperBob
and he suggested since I not a track guy, that I should start with a LWFW. The LWFW is probably about 1/3 of the weight of the stock dual mass unit. This option allows the engine to spool up much quicker.
As some of you know I removed my engine and transmission over the summer to do some fairly routine maintenance and as part of that project I installed a LWFW. After living with the car for a few weeks I would have to say that the car seems to be much easier to keep in the power band. Pounding on the car on the way to work this morning, I felt that the gearing was just about right. At least for street use. I don’t track the car, and do not race, but with the LWFW, I don’t think I need the shorter gears for the street. That said I still don’t use 6th gear.
I am not dissing the re-gearing modification. But for a relatively inexpensive mod I highly recommend the light weight flywheel. You won’t be disappointed with the improvement
Separating the engine and transmission was daunting at first. But after the work was completed it was really quite straight forward.
Probably way more that you wanted to know.
Thanks Steve Weiner and ViperBob for your insight and advice.
Bob-
- 3.8 L engine mod, $$$$$
- turbo charging, $$$$ and not recommend for the NA engine.
- supercharging, $$$$
- Re-gearing the transmission, $$$$ - I believe most of us have what is referred to as a G50/20
- Light weight flywheel (LWFW), $$
I had a discussion with Steve Weiner
and we talked about re-gearing the transmission. Steve argues that the car actually has plenty of power for the cars weight (which I agree), but because of the somewhat tall US gearing it difficult to keep the car in the “power band”. I think Steve is right on. There are lots of threads on hear discussing re-gearing to essentially shorter gears. I believe Bill Verberg and other are all over this.I also had a discussion with ViperBob
and he suggested since I not a track guy, that I should start with a LWFW. The LWFW is probably about 1/3 of the weight of the stock dual mass unit. This option allows the engine to spool up much quicker.As some of you know I removed my engine and transmission over the summer to do some fairly routine maintenance and as part of that project I installed a LWFW. After living with the car for a few weeks I would have to say that the car seems to be much easier to keep in the power band. Pounding on the car on the way to work this morning, I felt that the gearing was just about right. At least for street use. I don’t track the car, and do not race, but with the LWFW, I don’t think I need the shorter gears for the street. That said I still don’t use 6th gear.
I am not dissing the re-gearing modification. But for a relatively inexpensive mod I highly recommend the light weight flywheel. You won’t be disappointed with the improvement
Separating the engine and transmission was daunting at first. But after the work was completed it was really quite straight forward.
Probably way more that you wanted to know.
Thanks Steve Weiner and ViperBob for your insight and advice.
Bob-
Last edited by boulderbobo; 11-13-2009 at 08:47 PM.
09-18-2009, 12:49 PM
#2
RL Technical Advisor
Hi Bob,
Nicely done, Sir.
If you ever regear your transmission (something like the G50/31), the difference will knock your socks off,.... Its NOT a subtle change.
Nicely done, Sir.
If you ever regear your transmission (something like the G50/31), the difference will knock your socks off,....
Its NOT a subtle change.
09-18-2009, 01:36 PM
#3
Three Wheelin'
09-18-2009, 02:37 PM
#4
The lwf lets the engine rebuild and drop revs a little more quickl. Yes it s a nice mod, no it's nowhere near as dramatic a change in the dynamics of the car as a regear.
A picture is worth a thousand words, this graph shows the puch that actually acceerates the car vs the speed at which it is available. 2 trans are compared stock US g50/20 and a full race g50/30. The higher the curve the livelier the car will feel at that speed.
If you are into stop light drags, say 0-30mph you want the stock /20 other wise unless your goal is fual economy, you want a regeared trans.
Be aware that a regear doesn't solve all problems, you will have to shift more and the probablity of having to shift at an awkward place on track goes up as the ratios get closer together, but at least you have closer to the ratio you want most of the time.
I gotta admit I was stunned by the performance of a new 7spd PDK at Watkins Glen the past couple of days.
How would the performance difference be described?
If you are into stop light drags, say 0-30mph you want the stock /20 other wise unless your goal is fual economy, you want a regeared trans.
Be aware that a regear doesn't solve all problems, you will have to shift more and the probablity of having to shift at an awkward place on track goes up as the ratios get closer together, but at least you have closer to the ratio you want most of the time.
I gotta admit I was stunned by the performance of a new 7spd PDK at Watkins Glen the past couple of days.
09-18-2009, 02:49 PM
#5
Three Wheelin'
Thread Starter
09-18-2009, 02:52 PM
#7
Three Wheelin'
Thread Starter
The lwf lets the engine rebuild and drop revs a little more quickl. Yes it s a nice mod, no it's nowhere near as dramatic a change in the dynamics of the car as a regear.
A picture is worth a thousand words, this graph shows the puch that actually acceerates the car vs the speed at which it is available. 2 trans are compared stock US g50/20 and a full race g50/30. The higher the curve the livelier the car will feel at that speed.
If you are into stop light drags, say 0-30mph you want the stock /20 other wise unless your goal is fual economy, you want a regeared trans.
Be aware that a regear doesn't solve all problems, you will have to shift more and the probablity of having to shift at an awkward place on track goes up as the ratios get closer together, but at least you have closer to the ratio you want most of the time.
A picture is worth a thousand words, this graph shows the puch that actually acceerates the car vs the speed at which it is available. 2 trans are compared stock US g50/20 and a full race g50/30. The higher the curve the livelier the car will feel at that speed.
If you are into stop light drags, say 0-30mph you want the stock /20 other wise unless your goal is fual economy, you want a regeared trans.
Be aware that a regear doesn't solve all problems, you will have to shift more and the probablity of having to shift at an awkward place on track goes up as the ratios get closer together, but at least you have closer to the ratio you want most of the time.
Thank you.
Bob-
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09-18-2009, 02:53 PM
#8
Three Wheelin'
Thread Starter
09-18-2009, 02:55 PM
#9
yellow/red is the accelerative push available in each gear of a /20, the red region is where you want to run for best performance
similarly dark blue /light blue is for a /30 the best poer region is the light blue
The higher the curve the more acceleration at that speed
similarly dark blue /light blue is for a /30 the best poer region is the light blue
The higher the curve the more acceleration at that speed
09-18-2009, 05:31 PM
#10
Addict
Rennlist Member
Rennlist Member
I needed one a week ago. My boxster engine/tranny are on two jacks under the car (one on each side of the motor) and I feel like an idiot sitting there looking at them wondering how I am gonna get that clusterfark out from under the car.
09-18-2009, 05:39 PM
#11
Three Wheelin'
Thread Starter
We must see this please....
Bob-
09-18-2009, 05:58 PM
#12
RL Technical Advisor
You are never waiting for the revs to build before you get brisk acceleration; the car is always pulling hard toward the rev limiter since the engine is producing more torque at any given moment.
09-18-2009, 06:10 PM
#14
Three Wheelin'
Thread Starter
The gearbox that Bill illustrated never leaves you "waiting for the elevator",....
You are never waiting for the revs to build before you get brisk acceleration; the car is always pulling hard toward the rev limiter since the engine is producing more torque at any given moment.
You are never waiting for the revs to build before you get brisk acceleration; the car is always pulling hard toward the rev limiter since the engine is producing more torque at any given moment.
Man, wifey's gonna kill me...
Bob-
09-18-2009, 06:17 PM
#15
Rennlist Member
Those furniture carts are great for stacking wheels & tires. Gives you ability to move the whole stack from one place to another. I use the round cardboard separators in between each one. BTW, +1 for the Euro sport trannies. I had a 5-speed close-ratio in a Euro 635Csi and it was delightful.