[Mk2] [Turbo] Garrett Turbo Recomendations required befor purchase

[asbestos]

Hi all, i have finally finished my forged rebuild with all the usual bits ACL ARP, 1.8mm head gasket, 800sard injectors and fuel regulator, Apexi FC, boot mount large 4inch core skyline intercooler, bespoke top mount manifold, what would be a good choice of Garrett turbocharger, i seem to have narrowed it down to a GT3076r, GT3082r, GT35r is that to big? or the GTX models of those turbos,
I would like a few recommedations from people who have these turbos on their cars who have lived with them drove them ect so that i can make an informed purchase between performance lag and driveability as its a lot of money to spend on somthing your not happy with, im not tracking the car but would like it to be as quick as possible with what i have done to it, your honest opinions would really help, i have only ever drove large yank V8s before including a VXR Monaro so turbos are new to me,
Everything i have done is down to research on this fourm and i have really enjoyed it ( i have only ever drove the car 6 miles before stripping it down) so this is the last peice of the jigsaw
Thanks all.

[Mike N]

If you are used to large torqey V8 engines maybe a smaller turbo like a GT28 would suit your style more.

I had a Turbo technics stage two (T38 size) on my Rev2 forged, 9.0 cr, bored, big valved and cammed up lump incl 800cc inj and standalone ecu, it is very laggy which spoils every day driving around town as it lacked response at low revs, but when its up at 4krpm the power is very hard thru to 8k.

A ct20b that I had on the same engine as an interim unit had the power in at around 2.7k but was so much easier to drive on a daily basis and had plenty of low and mid range torque. It seemed to peak at around 7000rpm.

This may not have been the exact answer you were looking for but I hope it helps.

[sjm1984]

Depends on your power goals

I've got a GT3076 with external wastegate and its out round town and on the motorway

Full boost by 4000rpm and sounds awesome and really does kick you back in your seat

[RyanRs]

Tbh you cant really just have a few 'tasty' spec turbos and pick the best, you need to set your BHP goal, on which fuel and boost and put your data onto a few turbo compressor maps! Alternatively look on MR2oc.com as there is plenty of projects on there where many different setup's have been used. GT35 is a turbo capable of getting an mr2 into the 10 sec 1/4s with the right set-up, it can produce 500whp up to 700whp depending on what fuel you use! but you will encounter many little issues on the way and it will be a pig to drive on the road.

GT3071 Is a good street turbo, responsive yet makes good power and the 3076 is that little bit better, just with the slight added lag. If your considering GT35 then GT28 will prob disappoint you, its a great turbo but wont make anywhere near as much power as the 3076 ~ 35r.

Perhaps look at the HTA 3076r.. Billet compressor wheel means it can make almost as much as a gt35r yet spools quicker than a stock 3076!
http://store.forcedperformance.net/merc ... e=Turbo-FP

1.8mm HG is quite thick btw.. stock is only 0.8 (or 1mm? cant remember). how come so thick?

[asbestos]

Thanks for the replys, i used a thicker head gasket due to having the head skimed + my understanding from the forums was to lessen the compretion ratio a little for higher boost aplications,
that FP HTA GT3076R Ball Bearing Turbocharger looks interesting never heard of them before,

[mark239]

I've a GT3582r with the 0.82A/R exhaust housing and a ported compressor housing (The single best bit of it as I get no annoying surge any more) running at 2 bar and it's great fun tbh.

All home made and tuned.

Couple of pics from a recent car show

[RyanRs]

Mark, how much BHP & TQ have you made so far? do you have a dyno plot? and are you using pump fuel?

Might be having mine tuned on tuesday if all goes well!

[mark239]

no idea on power, it's nippy is all I know. rying to find somewhere local to hire a dyno to finish the ignition timing off.

I run a mix of 80% super to 20% methanol - much cheaper than race fuel.

A 1 ton cube of reagent grade methanol is only £280 at my local chemical suppliers.

I should add it's not a daily driver, it's weekend only. So the mixing of the fuel doesnt present much of an inconvenience.

[RyanRs]

Ohh thats interesting!! i have been considering a fuel blend for some time now as my mr2 is only a weekend / summer fun car.. only did 400 miles last year lol! Iirc i was looking into toluene / v-power iirc? Problem was that i could never find quite enough info to do it.

I guess that every time you get petrol, you have to count your litres then calculate how much meth to add, then just pour some in? Can you give me an idea of how much meth you would need to add to a full tank of petrol?

I would prob like to do this too, but obv if for a tank of fuel i need 20 litres of meth then i cant be carrying 3~4 jerry cans of meth everywhere in fear i might run out!! lol..

[T.F.S.]

there is info on home brews somewhere on www.max-boost.co.uk and a LOT of info on toulene on GTR.co.uk by a guy called toby/Kismet Captain

[sjm1984]

GT3076r