7MGT-W58 and 3.58 diff

**cambelt** · 13-01-2009, 09:05 AM

I know Ryley has tried it , any others . Turbos seem to love taller ratios .
Motor is 2psi moddified in a 1400kg car , so basicly stock.
Cheers Dave

**big_zop** · 13-01-2009, 09:33 AM

Dont mean to sound blunt but what do yuo want to know:
- will it be faster top speed or acceleration
- if the ratio is available or how to change the diff

And when you say 2psi modified, does that mean you have increased the boost by 2psi?

On a serious note, i can work out roughly how fast (or slow) it can accelerate if you give me more information and something to compare it too (say your current diff ratio). If thats what you want then ill let you know the details i need for your car.

**CrUZida** · 13-01-2009, 10:58 AM

I can state that by the seat of your pants its a slow as fuck.

Mine was running 9.5psi and it felt slow. I never time or tested it, or even had it dyno'd, so I can't say what power output it was. All I can say is the motor ran perfectly smooth and all checks on the motor proved positive.

I did plan to remove the 3.58 and replace with 3.909 but never got around do it.

**cambelt** · 13-01-2009, 09:08 PM

I just want to try a different diff ratio as well as fitting my GT LSD centre .
Im running 3.909 atm but would like to try a bit taller . 3.909 gives me a 13.3 1/4 mile at 101 mph , I have some traction issues 1st and 2nd gear .
Maybe 3.7s like a stock 7MGT would be better.
Dave
.

**Crambo** · 13-01-2009, 10:50 PM

I'm guessing this is a live axle, otherwise I could lend you an IRS 3.7 & 3.583 to try out?

**cambelt** · 13-01-2009, 11:54 PM

I may need a 3.7 , why i seem to have 3 x 3.58,s and no 3.7,s i dont know .
Dave

**TheStitt** · 14-01-2009, 05:22 PM

I run a 13.7 in the wagon with the above combo.

car weighs 1450kg. 7MGTE 192 rwkw. W58 3.5 live diff. Gets of the line ok. i might be able to find the 60 footers.

I turn the tyres in first and grip up real well in second.

I love the ratio on the road it still revs a bit high on the free way.

**oldcorollas** · 14-01-2009, 05:26 PM

try taller tyres for the track?

**cambelt** · 14-01-2009, 05:41 PM

Thats got me stumped , how does a crown weigh only 50KG more than my MX13 mark 2 . I do have Air and Steer but then a crown is full chassis and wagon .
I run 8.8 psi on a stock motor . made 175 RWKW .
Dave

**CrUZida** · 14-01-2009, 06:17 PM

Was that weight tested at WSID Stitty ?

**TheStitt** · 14-01-2009, 07:03 PM

that was what my weigh bridge ticket says

with more fuel and stuff I think ive seen 1500 ish at WSID

I run 8.5 pound with a high flow turbo

**Norbie** · 15-01-2009, 12:18 AM

I have a 3.58:1 diff in my Supra and used to have a W58. This was a vast improvement over the old 4.1:1 diff, far less wheelspin in first and second, plus the turbos had time to spool up properly before hitting redline.

Note this is with a 2JZ, 7M has different power delivery obviously, but generally speaking turbo engines with a manual transmission love a tall diff ratio.