R34gtt And R33gtr Suspension

[Nightcrawler]

I know these 2 cars suspension is outwardly the same (eyelets at the front, forks at the rear), and I often see suspension advertised as 'to suit R33GTR/R34GTT', but does anyone really know if they are a straight swap?

Of course the loads that each model has to carry is different - but assuming you bought damper adjustable shocks for an R33GTR, would they be any good in an R34GTT (assuming you had springs to suit R34GTT already)?

Has anyone tried this - I want hard proof - not just he said/she said. Thanks.

[nuffsaid]

I think they parts are interchangeable.

But they have slightly different specs.

ie. R33GTR might have different spring rates and valving?

[Sydneykid]

I know these 2 cars suspension is outwardly the same (eyelets at the front, forks at the rear), and I often see suspension advertised as 'to suit R33GTR/R34GTT', but does anyone really know if they are a straight swap?

Of course the loads that each model has to carry is different - but assuming you bought damper adjustable shocks for an R33GTR, would they be any good in an R34GTT (assuming you had springs to suit R34GTT already)?

Has anyone tried this - I want hard proof - not just he said/she said. Thanks.

<{POST_SNAPBACK}>

In developing the Group Buy kits I spent some time trying different spec shocks in different chassis and also shock dyno'ing them. The rear R33GTR and rear R34GTT shocks (Bilstein and standard) where pretty much the same, but the fronts were dramaticaly different. I don't know how technical you want to get, but I'll give it a try........

An R33GTR weighs around 200 kgs (25%) more on the front wheels than an R34GTT.

In general the common aftermarket spring rates are quite different, the R33GTR being somewhat higher to hold up that extra weight. Hence the rebound valving rates in the front shocks will be to high for R34GTT spring rates. You MAY have enough rebound adjustment on the shocks, it depends on the window of spring rates that their valving was designed for.

The bigger problem is bump (compression) valving rates, they are markedly different. The R33GTR front shock bump rate is vey high, it needs to be, to slow down the compression of the front suspension (that extra 200 kgs at work). Take away the 200 kgs and you wil end up with an excessively harsh ride, and handling prone to wash out understeer. This is because the front tyres contact patch will be compromised by the harsher than necessary bump rates.

Some shocks (most in fact) only have adjustable rebound rates, so adjusting them will do nothing for the bump rates. If they do have common adjustment (both bump and rebound together) the ratio of change in rebound rates will not match the change in bump rates required to handle the lower springs rates and the lighter weight.

You could run lower front spring rates to offset the higher bump valving, but then the rebound valving would be even further out.

The bottom line, it depends on the valving windows and only the shock manufacturer knows them. My guess, you could do better spending your money on correctly valved shocks.

Hope that helps

cheers

Edited January 23, 2006 by Sydneykid

[Nightcrawler]

thanks Sydneykid - that is the exact explanation I was after. Thanks very much for your time!!

[jonbatz01]

So the front suspensions wont be too short?

i just bought a set of tein 33gtr/3gtt shockies

the rear is fine but the front seems to short even after extending it fully...did i get rip off buy the shop or is it suppose to be that way?

[Nightcrawler]

yep I agree. I have put R33GTR coilovers in my R34 and the rears are all the way wound down and it still isn't as low as I want, and the fronts are wound all the way up and are still not legal height (but are close). Big problem is that as the fronts are wound all the way up, the spring is so compressed and the ride is hard as hell!

[Sydneykid]

Big problem is that as the fronts are wound all the way up, the spring is so compressed and the ride is hard as hell!

That's not the problem, the spring rate is designed for a car that has 200 kgs more weight over the front wheels. Ditto the shocks. Preload does not affect the spring rate.

cheers

[jonbatz01]

ahh feel a little relieve now...

so i should turn the back all the way down and the front all the way up....

NightCrawler wat size rims are u using?

will i have problems with 18s?

is there any way to raise the front a little more?

or should i sell it and get gtt specific coilovers...or maybe just springs..

[Nightcrawler]

I am running 8" front and 9" rear 17" wheels and get minimal front scraping with about 1cm more left to raise on the fronts. In all honesty unless you like really hard suspension, I would sell them and get R34GTT specific ones (as the R33GTR ones are made for a 200kg heavier car, as someone mentioned).

[jonbatz01]

so u can raise the front a little more...yeah i was going for same 17' 8 and 9s P1 racing...

any idea with the gtt specific ones will there be alot of height to play with...or are they the same as the gtrs ones just softer?

is it possible to send me a pic of ur car, wanna see the ride height

to [email protected]

thanx a million!

[Nightcrawler]

fyi I have had enough of the R33GTR HKS Hiper-Ds and am pulling them out. I am likely to buy some of the R34GTT Bilstein/Whiteline combo group buy from Sydneykid.

Bottom line is R33GTR suspension is NOT suited to an R34GTT