my na has a turbo box and will do ~40 in 1st, ~70 in 2nd over 100 in 3rd, at 120mph is around 5800rpm in 4th, never bothered checking 5th, dont have the patience

 

for the 2800/60 that means top speed is 6500/2800 x 60 ~140 MPH (theoretical), actually closer to 130...

mine (tranny number verified) runs ~72 at 2800
2nd is low, good for ~70+ MPH

 

Whatever.. I decided not to rant.

just find most any calculator and plug in

275-40-17
1.004 4th gear ratio
3.37 R&P

I shift at just over 7k in 3rd and it has no problem pulling to 7k in 4th at over 25 psi.

Add it up and show me how it doesn't compute.

 

My ROW turbo box does 90ish at redline in 3rd. FWIW

 

post a pic with 145/7k plus, here's one in 5th.

stock config is 1.03 in 4th and 3.375 r&P and i'm running 255/40/17's on the back so we're nearly twins.

87951
95sl320 dd

 

my calc shows you at, with that size tire and 7k shift point...
1st 45
2nd 77
3rd 114
4th 154
5th 192

 

BTW, somebody has created a spreadsheet to do these calculations for all 944 trannies at once (excludes 968 tranny and short 5th gear tranny).

http://www.924.org/techsection/7transaxle.htm

 

I may have been a poster in that thread, Alex.

I was hVing conflicting things with my S2. It would push almost 145 in 4th. As far as I knew, it had the stock S2 Trans. We debated for a while, and I posted all of my speeds in gear...when finally someone who had worked on my car told me it indeed had a turbo trans in it. S2 trans are considerably lower and your numbers definitely resemble a S2 trans. But hey, if you have an LSD S2 trans...I'm very jealous!!

And as far as going faster then 145 in 4th, I've done it. My 951 with a 7k rev limiter has done 149 or 150 in 4th. 285/30/18's, stock gearing with 240whp/250wtq.

 

Keep in mind that both tachs and speedos can have a lot of error. VDO's are notorious for reading 5-10% high.

Most mph/gear charts for our cars are setup for stock redline (6500) and stock tire diameter (approx 24.7" for a 245/45/16).

For instance - a 3.375 r/p (stock turbo), 1.400 (3rd) gear, at 6500 rpm w/ 245/45/16 tires will be approx 101 mph. 1.034 4th gear will be 136.8 mph. These are the common figures that you will see quoted for Turbo gearing (40 in 1st, 70 in 2nd, 100 in 3rd, 135 in 4th).

Sure, if you run 500+ rpm into redline and run 275/40/17 tires, you will be at 113.1 in 3rd, and 153.1 in 4th. But without initially saying that you need to be past redline and running taller than stock tires to do so, the numbers look high and will cause some doubt.

If you run 10000 rpm, you can break 160 in 3rd. And will break some other things too...

 

I did state that I have a 7k rev limit and my tires. I know my speedo may be off a little bit, but I can't see 10-15 mph. You would definitely notice that difference.

My car ran about 108 or 109mph in 3rd.

You must also take into account tire growth at said speeds. A 275/40/17 tire is going to grow more then a 285/30/18 will. So your calculations about gearing and tire sizes may be correct but your not accounting for tire growth. Either way...I hate getting into these debates. A stock geared 951 with a 7k rev limit will do 145 in 4th. It's almost a fact lol.

 

I see about 90-ish at the top of 3rd and about 130-ish peaking 4th. I can only explore a little bit of 5th... Pretty much stop pulling at that point.

 

Probably about right Alan, if not a little low. Seems like your car would pull some in 5th. Don't you have a few mods?

My 951 with 240whp pulled in 5th. Not hard but it would pull. To 165 in Mexico...

(I let off at 165. I had around 600rpm left and still pulling.)

 

2nd time i've asked you to post a pic of this wondrous event 145/7k+/over 25psi at 5k elevation.
i grew up in denver.

87951
95sl320 dd

 

I found roughly the same. Care to disprove the math bearone?

 

It pulls, but not very hard. The highest I've ever gotten it was 150 and I didn't feel like I should push it any harder. It just didn't seem to want much further. And as of now, I've only got an LR 3 inch exhaust.