997gt3north

- as i don't live in germany and get to drive 190mph, i have decided to re-gear the car by doing a r&p change (not going the gear route)
- the shop Powerhaus was recommended by my local shop
- has anyone done business with them? feedback?

- for those that track your car, what feedback would you give in terms of how would you set up your car (what would you pick as your top speed 165, 170, 175, 180?) - the top speed i currently see into the busstop at Watkins is 153mph and 155mph at Mosport - also, currently i upshift into 4th for the uphill esses at Watkins to avoid a 3rd to 4th shift, do you think a cup (4.0 or higher r&p) will make it necessary to shift during this section (something that i don't want to have to do)

- i know the answer is track specific but basically the tracks in my area are Mosport, Watkins, Tremblant + driving to these tracks as I will not be towing the car

- any and all feedback is appreciated

Paul

grussell

I changed the RP in my 997 GT3 to a 4.0 and there was an improvement but it did not solve the problem. The trans needs to be re-geared. Save the money on the RP and have custom gears made. For me we ploted 155 top speed and worked back to first with approx 1k drops. You can move 5th to 6th and buy new 1st - 5th gears.

Unitah

Grussell,
Have you done this yet? What do you think?
Jonathan

grussell

The work has been done but I have not driven it yet with the new gear set and 40/60 LSD. I will have her on the track next weekend at Willow Springs Streets for the POC event.

Unitah

So what exactly did you do?
New gears #1 through 5, moving original gear 5 to position 6
Final drive ratio 4.0
and LSD 40/60

What is the LSD ratio in the car stock??

Jonathan

grussell

Correct, I don't remember the OEM LSD split.

We also did 997 Cup uprights, center lock hubs, wheels, blade bars, 1200lb springs, trans mount and engine mounts, elect. power steering pump, removed the A/C, etc. I guess I have 2 Cup cars now.

tocho1

"i upshift into 4th for the uphill esses at Watkins to avoid a 3rd to 4th shift, do you think a cup (4.0 or higher r&p) will make it necessary to shift during this section (something that i don't want to have to do)"

gt3north, why dont u want to shift there if you dont mind asking me? i was at WG last week and was upshifting from 3rd to 4th right at the beg of the esse and all the way in 4th (sometimes 5th) into the bustop...

Sun Ra

i also changed my R&P to 4.0 and it lowered things a bit no quantum improvement. the LWFW is very nice BTW

997gt3north

you were doing as i was doing - i.e. shifting into 4th right at the bottom of the hill - earlier on i experimented with taking the uphill in 3rd but the gear ran out at the top of the hill and i didn't want to shift into 4th under load and upset the car so i had to wait until trackout was mostly over - later i found it was better to shift into 4th at the bottom of the hill and then when trackout was finished up into 5th (it was my first time on the track with the gt3 and i had heard a few horror stories about 996gt3s hitting the wall at the top of the hill so i was singularly focused on not upsetting the car at this point - with much more seat time now in the car i think this was likely only a 996gt3 rear bump stop suspension issue which has been cured with the 997)

- i now think with a smooth enough line and gear change you could take the uphill in 3rd and then change into 4th the moment the car straightens out at the top of the hill before the transition to the right hander - that all said it is likely safer to take the uphill in 4th (in 4th i was still able to hit 152 into the bus stop but i suspect that to get to 160 you will have to take the uphill in 3rd to start and you would be redlining it at 118mph at the top of the hill)

tocho1

Interesting...I think you definitely can keep the car in 3rd and upshift at the end of the esses but not sure if that way will be faster...I was driving my RS for the first time at a track and I was not redlining itsince it has not many miles yet but I did hit 143mph at the end of the straight in 4th gear...I think you can easily get to 160mph in 5th if you really go flat out from turn one on (I'm not that confident enough in the car yet to do this I must admit)

drane

My 2 cents, aftermarket gears will result in considerable more tranny noise than the well made porsche gears. I found this so both with powerhaus and GT gears with a G 50 unit. Consider the trade off, close ratio sweetness vs rinnging gears.

grussell

Agreed, but you cannot get the proper PMS grears for the 997 GT3 trans.

997gt3north

When I spoke with the powerhaus guy, his comment about the new japanese gearbox was that it was the best made gearbox they had ever seen in a production car but that the surgery for this new gearbox was going to be a one-off, $4500 not $3000, and the race shop would need to have a 45 tonne press - thus I may consider sending my tranny to them during the off season as my local shop doesn't seem to be equiped to do it.

Unitah

Grussell,
What did the electric power steering pump get you?

Do the new gears make more noise then the stock gears? I hope so, hahaha. I really don't care either way. As far as the car, how does it feel with the new gearing? Can you briefly describe the differences?

I did the engine mounts to the solid 993RS mounts everyone seems to use. I waited to do the tranny mount though until I do the gearing and LWFW, etc... All tranny stuff at once. Do you feel a difference with the tranny mounts? Or too many changes at one to tell?

grussell

993RS mounts are not solid, but they are better than stock. I have not driven it yet with the trans mount. It is much lighter and solid.