R33 Rb30 Conversion

[FORZA-MOTORSPORT]

Ok thanks SydneyKid ill try that if they do end up floatin . Any one know what the diff ratio and gearbox ratio are for a GTS4?? Is it the same as Gtr?

[FORZA-MOTORSPORT]

By the way anyone is SA who wants to come have a look while she is still in the air is welcome just drop me a pm, im in my final steps just bolted dump/front pipe with flex in, turbo and adaptor plate is on, just hooking up oil/water lines and putting wastgate on

[gtst25]

VL's have a 3.45 diff (V8's 3.08)

Wheel size doesn't have anything to do with diff ratio does it???

Wheel size directly affects your engine rpm so it has the same affect as changing diff ratios. The larger the wheel diameter the less rpm you will use for the same speed.

[platinum]

although, larger 'rims' doesn't mean a larger overall diameter of the mag/tyre - so it's generally okay with low profile tyres - ends up being about the same overall diameter (or very very close to it).

[gtst25]

Yeah got to agree there. In my commo days I went from 14's to 17's and the overall diameter once low profile tyres were on was just about the same.

[VHR32]

Wheel size directly affects your engine rpm so it has the same affect as changing diff ratios. The larger the wheel diameter the less rpm you will use for the same speed.

Yeah know that, I just wasnt sure what Sydneykid mean in his post.

I got a price for RB25DET valve springs from Performance Springs in Qld. $290 set delivered.

[Cubes]

Ash I've been thinking about your 223rwkw on 15psi (GT35) with 80-85% duty out of those injectors.. Either Shaun's dyno is reading a tad low or that gtr fuel pump your running is tired.

Was the pump second hand when you bought it?

[Bl4cK32]

arnt all gtr pumps second hand when people buy them

[mr_rbman]

Hey Ash,

If you wish email the larger pics of the dyno sheets so we can read them?

I'm curious how much louder its made the car? So overall... honestly. would you recommend the xr6 turbo on an rb30det?

Now that i've driven the car probably 100kms i have a good feel for it and am very impressed with it, i was expecting lag but with the good compression and torque of this motor u honestly don't feel the lag! The turbo builds boost nicely and doesn't just all of a sudden hit you!

But in answering your question i think the ultimate for this motor would be the .82/.86 or whatever it is like Andrew's (Sky30) but considering i couldn't get that with internal gate this was the best option and i'm more than happy with it!

I'll email you the graphs when i get a chance! (it holds 15psi really nicely with one of them actuators i bought from ATS so i don't even need a boost controller which is a bonus!)

The car is a little louder but sounds awesome, not sure if its due to the fact that i've put a straight through pipe through my cat though!

I think i'm still going to get new diff gears though, i'm 99% certain i'll get 3:9's

Edited May 20, 2006 by mr_rbman

[mr_rbman]

the pump was second hand! been on the dyno 3 times though with it in and haven't had a problem yet. I'm not too sure why the pump would be holding back the power though? Is it because if it isn't working how it should the injectors need to work harder to make up for it?

I'm not too sure what to upgrade to in terms of the fuel pump? I want something that i can just install as an intank pump (as i use my boot quite a bit so i don't want a surge tank or anything like that) but i've heard too many problems about installing the 044 intank if you let the the tank get below 1/4! But if i was to get the 040 i think that won't be good enough to cope with my power levels????

[Bl4cK32]

shaun put an 044 in mine no probs. Ive run it almost dry too without problem.

[mr_rbman]

shaun put an 044 in mine no probs. Ive run it almost dry too without problem.

really? thats good to know, i might go for one of them then cause there good for an easy 300rwkw's

Where did you end up getting your diff gears from?

Did you put your 2-way in yourself? if so was it pretty easy?

[Cubes]

Yes shaun does wonders with those 044's in tank, Bl4ck32's is so so quiet.

I gave Darren a had with his 2 way, was easy as.

[Bl4cK32]

yer i bought my diff as a whole pumpkin complete swap over.

Havent got a ratio set yet. People seem to want to sell the diff complete, so may end up going to a local wrecker.

If you are just changing the centres, i think they recommend changing the sideshaft bearings at the same time. If you can, take your diff out, then try a 4wd shop to do the centre swap as they can setup backlash etc...

[mr_rbman]

yer i bought my diff as a whole pumpkin complete swap over.

Havent got a ratio set yet. People seem to want to sell the diff complete, so may end up going to a local wrecker.

If you are just changing the centres, i think they recommend changing the sideshaft bearings at the same time. If you can, take your diff out, then try a 4wd shop to do the centre swap as they can setup backlash etc...

I see, not as straight forward as in and out with a diff oil change then?

Any idea what cars comes with 3:9's? might see if i can get some brand new!

[Bl4cK32]

3.9 is s13/180sx manual

[sky30]

Ash,

Good to see you got your car running, not a bad result for 15psi.

[mr_rbman]

Ash,

Good to see you got your car running, not a bad result for 15psi.

i was pretty happy to start with but as Joel (cubes) has said, my duty cycle is up around the 85% mark which doesn't seem right (should be up around the 250rwkw mark with that duty cycle) so i'm going to do a direct voltage feed to the fuel pump first and the grab myself an 044.

Now hurry up and get yours on the road, hehe!

[Sydneykid]

Yeah know that, I just wasnt sure what Sydneykid mean in his post.

185/60/14 = 905 revolutions per mile

245/45/17 = 808 revolutions per mile

That's an 11% difference, which means a 4.363 diff ratio with 245/45/17's is the same as a 3.9 diff ratio with 185/60/14's.

At 7,500 rpm with a 3.9 diff and 245/45/17's it's gunna do 305 kph. Do you really need that sort of top speed. If you don't, then all that effort/cost making the diff ratio taller will simply result in slower acceleration.

cheers

Edited May 22, 2006 by Sydneykid

[Bl4cK32]

yes, but its 2k for rims and tyres when a diff change will cost $500 odd...

(ontop of 10k+ spent on other mods )

Edited May 21, 2006 by Bl4cK32