3.8 vs 3.6

Reply Subscribe

Thread Tools

Search this Thread

12-04-2018, 08:22 PM

#61

Spyerx

Rennlist Member

Join Date: Mar 2012

Location: SoCal

Posts: 16,482

Likes: 467

Received 1,730 Likes on 1,058 Posts

Quote:

Originally Posted by Bill Verburg

What you want can be seen here, look at the red curves, compared to the blue. You want the red ones

Given I have a 5 speed and at this point not really wanting to invest in finding a 6spd + the full regear costs (know of a /30 for sale????) what compromise would I have to make? it seems with the /30 the split from 4-5 kept stock would be very long.

I know too many questions...

Reply Like

12-05-2018, 02:56 AM

#62

Peteinjp

Rennlist Member

Join Date: Jul 2017

Posts: 1,431

Likes: 60

Received 180 Likes on 140 Posts

Quote:

Originally Posted by Spyerx

Are you maxing out fifth on the track? What if you kept first where it is and brought 234 and five down lower?

Last edited by Peteinjp; 12-05-2018 at 06:03 AM.

Reply Like

12-05-2018, 10:34 AM

#63

Spyerx

Rennlist Member

Join Date: Mar 2012

Location: SoCal

Posts: 16,482

Likes: 467

Received 1,730 Likes on 1,058 Posts

Quote:

Originally Posted by Peteinjp

Are you maxing out fifth on the track? What if you kept first where it is and brought 234 and five down lower?

only 1 track here uses 5th so no, not even close i dont drive there much. But. I do like being at 3k cruising as it is a street car.

Reply Like

12-05-2018, 10:44 AM

#64

Bill Verburg

Addict
Rennlist Member

Join Date: May 2001

Posts: 12,249

Likes: 3

Received 509 Likes on 349 Posts

Quote:

Originally Posted by Spyerx

Here's a comparison of a stock 03 w/ 275/35 x18 tires, a /30 and 2 possible regears, opt 1 is se the /30 gears for 2, 3,4, the downside here is the big jump to 5. opt 2 is use /30 for 2,3,4 and the a 1:1 5th the down side here is higher cruise rpms. I added the range of each gear, this is something that would be useful to look at at to see how it matches w/ your local tracks. I'd also look into possible using a shorter tire, either a 285/30 or 265/35, It does depend on the track but in general I like what the shorter tires do.

Just from my own experience the /30 is a perfect transmission for a stock or moderately modified 3.6-3.8. The money gear on the track is 3, w/ 2 & 4 close enough to be useful, 5th is then there for the longer straights, only place I have ever used 6 is Monticello, It's got a Talladega like straight that ends in a 2nd gear switchback, very tough on the brakes

Reply Like

12-05-2018, 11:31 AM

#65

Gus

Rennlist Member

Thread Starter

Join Date: Jul 2003

Location: Peachtree City, Ga

Posts: 1,940

Likes: 0

Received 60 Likes on 50 Posts

Just bouncing in - of the tracks I run I get into 5th on a few (VIR, RA+). I pull around 5800 to 6000 in 5th on the back straight at VIR, depending on wind and exit from the Oak Tree (tight right turn)- low 3rd pull, but not worth going into second. This is the fastest track I run. I can see that I could drop 5th ratio lower, but because I do drive on street so prefer to hang on to the current ratio.

Reply Like

12-05-2018, 01:05 PM

#66

911Jetta

Rennlist Member

Join Date: Dec 2003

Location: NC

Posts: 7,214

Likes: 2,051

Received 485 Likes on 278 Posts

Quote:

Originally Posted by Gus

+1 The back stretch (and start/finish) are mega fast at VIR. 6000 in 5th at VIR in a 964 is pretty exciting... then on to rollercoaster where it gets even more exciting. Haven't been back in years. Love that place!

Reply Like

12-05-2018, 02:25 PM

#67

forklift

Rennlist Member

Join Date: Nov 2003

Location: VA

Posts: 2,182

Likes: 24

Received 12 Likes on 9 Posts

If I go through Oak well enough I'll hit my rev limiter in 4th right before I need to brake at VIR on the back straight. With 275/35/18s that is a max speed of 140.xx. I don't use 5th gear w 275s....