Rennshifter experience?, Specifically, 1st gear selection... Options

[jhadler]

Hi all,

I've long toyed with the idea of getting gobs more rubber under the car, but the main detractor has been the significant increase in gearing that I'd get going from 225/45-15 to 245/45-16. With all of the glowing testemonials about James' creation, I'm wondering how much easier 1st gear gets.

The increase in gearing would mean I'd actually need to use 1st on the autox course, and even with the welty short shifter, needing to shift to 1st while on course is a huge loss of time.

Thoughts? Experiences? I'm looking for specific observations about improvements in 1st gear selection.

This is strictly research right now, but I'd really like to hear from you...

Thanks,

-Josh2

[Twystd1]

Josh, I have no clue..

I just think this is an EXCELENT question.

Can't wait to see the answers from
fellas in the know.

Twystd1

[MattR]

You really think you'll use first gear in an auto cross? I'm guessing even with the increasing rolling ratio, you'll still be in 2-3rd gear mostely.

But I have driven a car with a Rennspeed, and though its not a new car, its significantly better then a standard 901. First gear was a breeze. No issues there.

[Aaron Cox]

its a load easier!!!! get new shift bushings while you ar on a shifter crusade.

it rocks. everything is "gated". feels gerat.

[ConeDodger]

I just had Martin Baker put mine on and adjust it. I have not autocrossed it as yet. But I do have some grinding going in to first gear if I don't match the revs and ease it in. My opinion is that this doesn't have anything to do with the Rennshifter. It was there before. It is either wear in the synchro or character of the 901.
I am running 205 50 15 rubber and I believe just from the little amount of driving We (Martin) did Sunday night and the driving I did on Monday that I will be in 2nd and 3rd on most courses...

Rob

[SirAndy]

its a load easier!!!!

(IMG:style_emoticons/default/agree.gif)

especially first as you now can "feel" where you are, gear-wise ...

one word of caution tho, on the big track, make sure you had *plenty* of time to get used to the springloaded shifter as trying to shift fast in the 4th/5th plane can now easily leave you with 3rd instead of 5th!!!

you need to actively push the lever to the right when going from 4th to 5th, otherwise the springs will push it back into the 2nd/3rd plane and that can get really expensive really fast ...
(IMG:style_emoticons/default/icon8.gif) Andy

[North Bay 914]

Since leaving Germany, doing AX with the PCA Germany Chapter (Now Gone), I have yet to attend an AX in the USA where you get any gear higher than second which is a little boring. Once I let the car bounce off the rev limiter a few feet during the run, which was faster than a change to third and back to second. We always had to shift at least to third, but German folks are different in that way. What fun would it be to drive really fast with no gear changes after your first to second shift? I now know...

In most cases, a shift back to first may actually cost you time. 901 gear boxes and first gear down shifts are not done quickly, reaguardless of how much your shifter costs. If you want to shift more, intsall a 904 main shaft and a lower second thru 4th or 5th gear. Then the are many ratios to choose from. You should be quicker, as long as you have good shifting technique, so not to spin ths car when you are on the edge of your cars ability. Less than butter smooth heel/toe downshifts can spin a car very quickly, ask me how I know!

[carr914]

I've run 225-50-15 Michelin slicks, up to 225-50-16 street tires and even with a very tight corner I've never gone to 1st, but I've got a VERY torquey Six. The RennShifter would give you a better feel for where 1st is, but I think the issue would be your gearbox and how good your synchros are AND how well you shift to begin with.

T.C.

[J P Stein]

I can downshift to first just fine, thanx. I have never been able to justify the expense of the trick shifters.
I was able to justify changing gear sets to make first useful....2nd too......for just a bit more cash than the shifter. (IMG:style_emoticons/default/confused24.gif)
I try to put my money where it will do the most good.....I get it right about half the time.

[john rogers]

When I race the street circuits in Mexico I have to shift into 1st, usually twice a lap when doing a U turn at the end of a street or similar. I am usually going about 25 MPH or so when I do this and so far have had no problems. But, I use a sealed aircraft coupler in place of the factory one, new bushings each year and the trans has a pump and cooler. I do shift somewhat slowly and carefully and I shift this way through all gears.

[jhadler]

Thanks for the responses so far, keep 'em coming!

The car has a stock 2.0L 4 cyl. So having massive six-like torque is not on the table. I don't know what autoxes you've run at, but nearly all I run at are 2dn and 3rd gear. Heck there was a GGR autox I went to where I actually needed 4th! Yeah, not an autox... I digress... The issue I've been looking at is that going up to the 245's will increase my rolling diameter by roughly 2 inches. That increases my top speed in second gear from 49 mph (at 6000 rpm) to 53 mph. I know that may not seem like a huge change, but what that does is put me even further down when entering a tight corner (<30 mph), and with the taller gearing from the larger wheels and tires, I'm worried that I'd need to drop down to 1st to pull out of the corner. Goign for 1st gear on an autox course is like getting out and pushing... (IMG:style_emoticons/default/dry.gif)

Anyhow, keep the comments coming! Thanks!

-Josh2

[J P Stein]

My prior set-up got 37 mph out of 1st & 57 out of 2nd.
With the new set up, I can get nearly 44 mph from 1st & 64 from 2nd.....both @7100. I can change the pill & go up to 7300..or 7500 (IMG:style_emoticons/default/blink.gif) ..and I shoulda done it this last weekend.

Many of our AXs have a slow section (including this last weekend's) at the start.
One can terrorize tight corners in 1st gear, but......as Brit and I found, it takes some learnin' to do precise rear-steering with the go pedal.....wanna rotate? gas it.....but be gentle. Most all the time to be gained
on that course was in that first section. With the old gears, I woulda had to put it into 2nd & bogged the motor in the tight stuff that followed....

On other courses, I found my self on the limiter in 2nd way too often....but didn't want to go to 3rd for 50-70- feet & then have to downshift. Tha extra 7 mph should make a hell of a difference.

To keep this somewhat on the subject:
A trick shifter won't cure worn dogteeth/sliders/bent shift forks/worn bushings/totaled motor mounts/limp shift rod couplings.... did I miss anything?

[Joseph Mills]

Before I rebuilt my tranny you had to be at a dead stop to shift into 1st. The original owner of my car had taught both his daughters how to drive in it. (IMG:style_emoticons/default/biggrin.gif)

I can now shift into 1st going 25mph.

If you have a good syncro and if you have fresh shift linkage bushings, the Rennshifter will make it shift even better. However, you will still need to heel/toe to bump your rpms for 1st gear.

James offers two grades of spring stiffnes. I use both. I use the softer ones for gear 4 & 5, and the stiffer ones for 1st & reverse. This helps me to avoid accidental shifts.

But I haven't shifted into 1st gear on an AX course in two years since I attended an event in Tulsa. The PCA there has really tight ass courses. Some people like them. I'm not one of those people.

I always shift into 3rd at our events and sometimes 4th as well. Our SCCA group likes fast and open courses. I am running 225/50 15's.

What JP said makes sense. When I rebuilt my tranny, I picked up an extra 5th gear set and flipped it in place of 3rd. That is a sweet AX combo (but it will suck for track use because it creates a really wide gap between 3rd & 4th).

I think even with your larger tire, that's going to be one hellavu tight turn to require shifting into 1st. My engine has a decent low end. It produces 116 lbs of torque at 2300rpm to 5300rpm. I would almost have to be at a dead stop to elect to shift back into 1st.

However, if ya gotta do it, ya gotta do it! I have my shift rod biased for the easiest shift to be upper gears, and it just barely shifts into 1st. You could adjust your shift rod linkage (at the shifter lever in the cockpit), just the opposite. That would definitely help you.

Good luck with it! (IMG:style_emoticons/default/driving.gif)