Rb20det With Garett Gt2871r To Laggy?

[Dale FZ1]

Any graph to view? The outright power figure is very impressive for the boost you've run.

How are you finding the 56T / VG30 combination in terms of streetability and response with the 2.4 litre capacity?

[kwazza11]

i will get a graph once i get the tune checked over, i havent got one printed since the headgasket was changed. but had a quick look at the run he did and it had 12psi by ~100kph in 4th.

actually it feels really good, mind you i havent really tested it properly as i'm abit unsure how healthy the tune is, but the rb25 housing felt better in regards to response but had surging and boost spiking issues.

[RNS-11Z]

on my sr20 with 2871r 56t, im making 18psi in 4th @ 3500rpm .64 rear

[salad]

but SR20s spool turbos better than rb20s due to their longer stroke

what is the compressor and turbine A/R on the hks GTRS?

currently im really keen on the GT2871R highflow cos it all bolts up, and from what i hear, the exhaust A/R is 0.63

[Dale FZ1]

HKS unit has comp .60A/R, turbine .63A/R.

A carefully thought out high flow can work very well, but the apparent aims of factory engineering needs to be factored in when using factory-spec housings.

In some respects I'm not massively surprised that kwazza11 had troubles with surge with the 56T comp and 2.4 litre capacity. My calcs for the RB25 suggested it would be borderline, depending on the power target. Using the VG30 turbine housing is a way of masking a technical mismatch and still getting a satisfactory overall performance characteristic. If the compressor is not excited as easily due to the higher flowing turbine, then it will not be pumping as much air at the middling engine revs, giving a marginally lazier transient response but eliminating surge - and also giving excellent high end power. I actually think it was a clever and practical way of making the turbo mate well - just not how I would have/did do it.

If you are insistent on doing a Garrett GT2871R cartridge type high flow into RB20, depending on your exact objective then go either 48 or 52T comp, and use the RB20/25 turbine housing. If you can get some piping mods sorted, use the Garrett 0.60 A/R comp housing and have something close to a GT-RS. Just remember the more fabricating you have to do, then the financial advantages of going with this decision start to diminish.

cheers

Edited September 9, 2006 by Dale FZ1

[Rolls]

Not really on topic but dale fz1 you sound like you know a fair bit about turbos, can you recommend any good reading, books articles etc for learning about flow maps, how to match compressors to a/rs to motors etc?

[Cubes]

Corky Bell's Maximum boost is a good starting point.

http://www.themotorbookstore.com/maximum-boost.html

[kwazza11]

i agree dale, the 56t matched to the rb20/25 housing is definately on the edge. would be even worse on the stock bottom end, i actually order the 52t 2871r in the first place but the workshop i purchased it from sold me a 56t telling me it was the 52t, when i questioned him about it he said he hadnt realised and offered to chase up the proper comp but called me back 2 days later saying it would take him 2-3 weeks to get the wheel in. was sick of his BS by then so i ended up just keeping the 56t.

the turbo works really well, just make sure you have the wastegate bored out as much as possible if using any of the nissan housings.

[RNS11Z]

here is my dynp graph that i ran a 13.2 @ 113mph with. I think there is 115mph in it actually. Feels strong

[kwazza11]

looks good, nice and responsive. is that using a internal gated housing or ext? boost spikes quite a bit after 6500rpm.

[RNS11Z]

its internal gated

have always had boost issues, previously, boost always dropped off, now spikes. Changed controllers no diff.

Its all good though, car doesnt ping and knock levels do not go over 20

h.

[Dale FZ1]

Not really on topic but can you recommend any good reading, books articles etc for learning about flow maps, how to match compressors to a/rs to motors etc?

We'll stick on-topic here, but try

www.turbobygarrett.com and read their tutorials; they are very, very good and easy to follow

Turbochargers by Hugh MacInnes (if you can find a copy, will be in specialist bookshops).

I have another text that was published early 90s and still on loan to my mate.

cheers

[Dale FZ1]

its internal gated

have always had boost issues, previously, boost always dropped off, now spikes. Changed controllers no diff.

Its all good though, car doesnt ping and knock levels do not go over 20

h.

That you have knock apparently well controlled is a good thing.

I wouldn't be at all happy with the boost skyrocketing at the top end of the rpm range - recipe for a hand grenade under the right (read: wrong) conditions.

So your 2871R is fitted to an SR20, uses a .63 A/R turbine housing? It's a stock, off-the-shelf Garrett unit fitted to a fairly stock engine and manifolds?

What was changed that you went from boost falling away to boost running away?

Main point of interest is if there are any lessons to learn in fitting a similar spec unit to an RB20.

cheers

[RNS-11Z]

Hi boost at top end is not an issue, as i dont take it past 7000rpm. As you can see from the dyno. Hi boost is an issue down low, as thats when rods can break. Up top you'l only damage rings (so i have been told).

There 2 things that we are assuming which is the problem to why boost sky rockets

1. I have re-ground exh cam with ajd cam gear - that may need adjusting. Have set it to 0 and just fitted cam. If i play with the timing it may stop the boost spike and give me a fatter mid range.

2. Wastegate hole needs to be machined

I wont be doing anything for now as im happy.

[RS500]

If you are insistent on doing a Garrett GT2871R cartridge type high flow into RB20, depending on your exact objective then go either 48 or 52T comp, and use the RB20/25 turbine housing. If you can get some piping mods sorted, use the Garrett 0.60 A/R comp housing and have something close to a GT-RS. Just remember the more fabricating you have to do, then the financial advantages of going with this decision start to diminish.

cheers

i agree with Dale in that the ideal combo for a RB20DET would be a 48T GT2871R with a RB25 exhaust housing. this would allow the turbo to easily mate with the standard manifold and dump pipe if required.

the 56T comp wheel is just too big for the 76T turbine where it is able to flow enough air for ~475hp, whereas the 76T's efficient limit seems to be ~400hp. Also, i believe the 52T is probably as big as you'd like to go on the GT2871R although be it with an A/R .86 exhuast housing for ease of flow and increased efficiency.

if you look at the garrett website (www.turbobygarrett.com), you will see that the efficiency of the 76T turbine actually decreases as you go bigger in compressor wheel.

anyway, just my 2c, feel free to put me in my place if you feel you need to

[Roy]

would be interesting to see how your set up goes on this dyno...there should be a dyno day at DrDrifts in a few months time......time for a few myths to be busted

When your ready ball bearing boy

[Interloper]

i'm free almost anytime.....except 8am-6pm weekdays -> i have got a job since we last talked about this.

you have pm.

[SoFly]

planning to hit one of these babies in my rb20 also..

just wondering what housing would be good for it?

thanks

[grippy]

I have just purchased a HKS GT2530 upgrade kit from nengun Japan for my R32-RB20DET as my stock turbo shredded all the turbine blades like potato chips last week. I have been doing tons of research into which is the best and most practical turbo upgrade for the RB20 with T3 flange and I have decided to go with the 2530.

I have a long way to go and alot of mods to complete the project. I will keep you updated on how the installation goes and on final dyno results.

There are so many paths to take when upgrading the RB20 turbo. I hope my experience will help some of you to make the choice that is right for you.

Rgds, Grippy

[RedDrifter]

I have just purchased a HKS GT2530 upgrade kit from nengun Japan for my R32-RB20DET as my stock turbo shredded all the turbine blades like potato chips last week. I have been doing tons of research into which is the best and most practical turbo upgrade for the RB20 with T3 flange and I have decided to go with the 2530.

I have a long way to go and alot of mods to complete the project. I will keep you updated on how the installation goes and on final dyno results.

There are so many paths to take when upgrading the RB20 turbo. I hope my experience will help some of you to make the choice that is right for you.

Rgds, Grippy

Yeah well I'm in the same boat too but I ordered the HKS GTRS. It should be here sometime this week from nengun. Could be a few weeks yet till I can install it but it should be a well worth the wait.