Whoop Ass Wednesday - NOW ON 22 FEB '06

[CrUZida]

4.1 will be slower than a 3.7 on your car.

[Stomps]

i dont really deal with that sort of stuff, can you please explain..

cheers

Stomps

[JustCallMeOrlando]

Nope, I've gotta reattach the thermostat housing. Should be good to go Saturday morning.

Reasoning being the 3.7 will put more load on the turbo and get it boosting faster. Also means you get a usable first gear because it's not laden so much with wheelspin.

[Stomps]

ahh, cheers, didnt think of it like that... i might have to try before i buy...

cheers

Stomps

[WA_TRD_83]

time to shut this one down..

new thread started for new drag night..

cheers
Damo
TRD 83

[Wildsupra]

Reasoning being the 3.7 will put more load on the turbo and get it boosting faster. Also means you get a usable first gear because it's not laden so much with wheelspin.

im gunna have to pipe up here about this and disagree (no offence nathan or andrew)

in my opinion (which could be completly wrong) i believe stomps car will be quicker with the 4.1 diff, i can see what your saying nathan about the 3.7 giving it longer to make boost...... but the simple fact is stomps car is pretty laggy compared to the rest of us, then comes on strong later in the revs. It makes great power, but only high in the revs, i think he needs to get those revs up as quick as possible and keep em up, he has more trouble with it bogging donw rather than spinning off the line (especially when he gets an LSD) if the engine doesnt make power low down in the revs (like it showed on his dyno chart) then you dont want the car to labour low down because it cant make the power until later.

The way i would explain what nathan is saying is, if i put my supra in 3rd at 30k's it would probably hit full boost pretty quick (maybe 2000 revs) but it wont make stuff all power and hence will still be going slow. If stomps had 300 horsies from earlier in the revs then sure change the diff ratio closer to 3.7

Wow wot a bloody novel. Hope some of it made sense.

Cheers
Matty

[CrUZida]

If stomps has more trouble bogging down off the line then his launching technique needs work, its nothing to do with the diff.

On most NA cars and positive displacement chargers a shorter diff ratio works well, but on a turbo motor you need a tall diff ratio.

The taller the ratio, the higher the load, the quicker it will come on boost, and the LONGER it will stay in the power band.
Sure, it will take longer to reach redline in first gear, but for the rest of time after that you will benefit.

[EldarO]

i sense that they're all giving you the wrong advise, simply because they're trying to make the p00 motor go slower

Matty has a point, but then again, so do Andrew and Nathan.

Stomps, you know what to do, Matty fire up that MIG and see if it'll make a difference

Eldar.O.

[Wildsupra]

If stomps has more trouble bogging down off the line then his launching technique needs work, its nothing to do with the diff.

On most NA cars and positive displacement chargers a shorter diff ratio works well, but on a turbo motor you need a tall diff ratio.

The taller the ratio, the higher the load, the quicker it will come on boost, and the LONGER it will stay in the power band.
Sure, it will take longer to reach redline in first gear, but for the rest of time after that you will benefit.

hmmm i see your point also, another factor will be what gear he is when he crosses the line. How close to redline is he? i would assume this might help him better choose the right ratio also.

Personally i was running 4.3's when i used to run consistent 13.1
then changed to 4.1 and ran 13.3 - 13.6's both with the same hp.
Then more hp showed better trap speeds bringing it down to 12.80 with the 4.1 because the 4.3 diff was putting me on limiter very close to the line.
surely if i dropped a 3.7 in mine id run slower because i dont have the hp to pull the heavy car quicker. Which is where i get the same idea for stomps, i wouldnt say he has tonnes more power although he does have a bit, but i wouldnt have thought enough to need the 3.7.
The only other factor may be gearbox ratio's being different also, is stomps using the 58 or the 154? as that would make the diff ratio's less comparable between our cars.

Matty

[Alien]

holy information overload :S but still im learning

[CrUZida]

R154 vs W58 the ratios are very close and comparable.

[EldarO]

stomps is using an r154 anyway...

Eldar.O.

[CrUZida]

Go Matty and Pimp!

http://video.google.com/videoplay?do...soarer&pl=true

[JZA70 R]

you cant blame stomps for his 60 footers, its not the driver in this case, its his powerband and the way the car is setup. There is not one thing going in his favour (nor mine) with the way the car is setup.

trying to launch our cars off the line with consistantly low sixty footers is like trying to beat the computer on super hard level. it happens once in a blue moon.

...lol wtf am i talking about?

[chris davey]

re gear ratios: as quite a few of you would know, I have very short ratios in my car and it really wasn't working. I had a 4.875:1 and now have 4.625:1. I am going to very tall tyres to offset this.

Wildsupra: I understand what you are saying but I think the difference is that your setup will have minimal lag anyway so if you can get it to load up a bit more as well as being able to leave it in a gear rather than change at the end of the 1/4 the time should increase.

If bogging down is the problem, give it some more revs first and see if it goes into crazy wheelspin or not. A lot of people with street turbo cars use the 3.7-3.9 ratios with a lot of success although most I know are auto.

4.1's are generally excepted by the v8 crowd to be a good medium with gearing but the low down torque of these cars helps them get off the line easily.