[Mattszook]

Hey guys I have a serria with the gti swift motor in it both 1.3l she is fine first 2nd 3rd but 4th and 5th is so slow I'm running 37s Muddys I've been told these will so it down but not shore It has hilux diffs 4.8 ratio also been told that will slow it up but it's a pretty expensive mod to change to 4.3 when there is nothing wrong with them, second problem my rear tail sharft is eating its self I hav a spring over convershion wats the fix everyone's been doin to fix that angle?
Cheers guys Matt also if anyone has hilux diffs and want to swap I will

[atari4x4]

let me get this straight, you have 37" tyres & you expect it to be a rocket ship powered by a 1.3?

changing to 4.3:1 will make it worse off road... it's 6 of one 1/2 a dozen of the other, you can't rob peter to pay paul.

double cardan joint & a track bar should help out the tail shaft.

[shep]

I put your setup into a gearing calculator and it says your crawl ratio is worse then a stock Sierra and you will be doing 3342rpm at 100kph. Mate you need To be doing at least 4000rpm at 100kph to have any chance at it being drivable.

My Sierra is 4.57 diffs and 6.5 trans gears and that is just for 33s

[Aaron]

My guess is with the tailshaft is that you don't have an offset pumpkin on your rear diff so the tailshaft will run on an angle. also could be pinion angle if it is a dodgy spring over.

[Red89]

What TC gears do you have ? Ive got 5.14 TC and 5.29 in the diffs on 38's and I can get it up to 60/70 odd without too many dramas but I run out of gears then.

What driveshaft do you have, Sierra, Lux DC or Lux uni ?

[Gwagensteve]

Wow... (and what all of them ^^^ said)

Did you buy this car like this or have you built it, because it sounds a bit like it was either built by someone with little idea of what they were doing, or you've bought something that someone has taken all the good bits out of before passing on.

The only thing that will "slow down" a sierra with those tyres/diffs is their added weight, so long as the gearing is right, which it's not.

I ran my calculator and got 2838rpm @ 100km/h (?) based on what you've told us about the setup. That's terrible. Really terrible.

If my calc is right, third gear would be about right for 100km/h.

Mattszook, if you want your car to be drivable, you need at least 4.88 diff gears and 6.4 transfer case gears. This will give 3800 rpm @100km/h, which might still not be ideal. 5.29's in the diffs will take you to 4100rpm @ 100km/h with 6.4 transfer gears which would be sweet for a heavy car and a GTi motor.

The rear driveshaft it chewing out primarily because you have an offset transfer case and a centred rear diff. That's why a bundera rear housing is much better suited to a sierra. I also imagine you have lots of lift height and you might be wrapping the springs pretty badly trying to pull away with tall gearing.

Sounds like you need to invest some $$$ in your car. These problems have all been solved before by others, it just takes time and money. There's no shortcuts.

Couldn't post a pic could you?

Steve.

[shep]

What calculator do you use Steve?

I use this one http://www.grimmjeeper.com/metric_gears.html and got 3300@100kph. If you to something different then I am hoping I didn't stuff up the numbers for my build

[Gwagensteve]

I just ran that and got 2751rpm?

Steve.

[shep]

What do you get for 4 speed vitara auto, 6.5s, 4.57 and 33" tyres? I am sure when I first worked it out I was getting 3800 ish @100kph now I seem to get 3600@100kph

[joeblow]

This should sort your problem out but you WILL have to upgrade the brakes I'm told.

http://www.ebay.com.au/itm/BAC-TSR2-RAF ... 1e66d4b369

[Gwagensteve]

I get a bit under 3700, which rings true - when I crunch my setup I get 3735@100, which matches what my GPS tells me.

AW-4, 6.4TT, 5.12, 35.


Steve.

[Rusho]

joeblow wrote:

This should sort your problem out but you WILL have to upgrade the brakes I'm told.

http://www.ebay.com.au/itm/BAC-TSR2-RAF ... 1e66d4b369

[Aaron]

Steve said it better than I did (his wording makes sense hahaha). But with a little more info I.e. about rear diff more suggestions could be offered

[shep]

Gwagensteve wrote:

I get a bit under 3700, which rings true - when I crunch my setup I get 3735@100, which matches what my GPS tells me.

AW-4, 6.4TT, 5.12, 35.


Steve.

Thanks. Hopefully I can keep the 33s and still tow 1400kg

[Mattszook]

Hey guys thanks for the bad news lol It use to be simozook from on here the rear diff is a Bundera diff it's 4.88 And it's running the stock transfer at the moment but I have a twin stick 6:5:1 ruduction if u guys think that should go back in but would that slow it up more? I'm getting a tailsharft made up to fix the angle, wat would the best ratio for me? Should I drop the tryes size

[Zook_Fan]

It will slow the theoretical maximum speed of the vehicle but will increase the actual speed that the car will be able to get to by increasing torque from the 1.3 at the wheels. Yes definitely put that in if you already have it.

[JrZook]

shep wrote:

Gwagensteve wrote:

I get a bit under 3700, which rings true - when I crunch my setup I get 3735@100, which matches what my GPS tells me.

AW-4, 6.4TT, 5.12, 35.


Steve.

Thanks. Hopefully I can keep the 33s and still tow 1400kg

Moar gearing! You got any other options to lower the gearing further? Towing that much and maintaining 100KPH I'd be looking to run closer to max torque so somewhere around 4-4.5k

[Mattszook]

Ok sweet thanks but should I drop the wheel size to maybe 33 and and change the diff ratio? Will this make my rig better and sort all probs I don't mind paying a little to fix it
Cheers Matt

[shep]

Hay mattszook. Do you have any contact details for simozook? Would be awesome if you could pass them on to me.

[shep]

JrZook wrote:

shep wrote:

Gwagensteve wrote:

I get a bit under 3700, which rings true - when I crunch my setup I get 3735@100, which matches what my GPS tells me.

AW-4, 6.4TT, 5.12, 35.


Steve.

Thanks. Hopefully I can keep the 33s and still tow 1400kg

Moar gearing! You got any other options to lower the gearing further? Towing that much and maintaining 100KPH I'd be looking to run closer to max torque so somewhere around 4-4.5k

I mostly travel at 80-90kph anyway. How do ya kick back, relax and enjoy the scenery at a crazy fast 100kph?

It tows fine at 80 with a worn out 1.3, 6.5s and stock 5speed and wt diffs as long as I drive in 4th and seeing as I have owned quite a few landcrusers I am used to towing in 4th. should be fine with a 16v 1.6 and a squirt of gas for overtaking

[Santos]

shep wrote:

I mostly travel at 80-90kph anyway. How do ya kick back, relax and enjoy the scenery at a crazy fast 100kph?

It tows fine at 80 with a worn out 1.3, 6.5s and stock 5speed and wt diffs as long as I drive in 4th and seeing as I have owned quite a few landcrusers I am used to towing in 4th. should be fine with a 16v 1.6 and a squirt of gas for overtaking

I take it most of the places you drive in the NT is relatively flat? 300km in any direction out of sydney is mostly up and down. Personally i like being able to hold 110 with stock gearing and tyres

[Mattszook]

Don't wanna be as fast as a thousand rapped apes but I wanna do 110 to keep up with the trols

[shiv]

Did simozuk do a build thread?

[gvzookdriver]

Hijack

What is the optimal rev range at 100kph ?? My car will be doing 3400 is this ok? Or will I require more gearing.

[Gwagensteve]

3550 is pretty close to stock for a 1.3 Sierra.

[SierraDan]

Mattszook wrote:

Don't wanna be as fast as a thousand rapped apes but I wanna do 110 to keep up with the trols

If you drive it on the road often. Go back to 35's and chuck some 6.5's in it. If its mostly offroad with road driving just to the bush just chuck 6.5's in. Then think about a 1.6/auto.