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Small Single Options? (Rb26)

Idon28
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Idon28 Contributor

Idon28

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Hello,

I am looking to do a single turbo swap for my RB26, but Im not really chasing big power, even stock power or little over stock is okay, Im mainly concerend with responce and having a broad power band. and also the simplicity of a single turbo and accesability appeals to me. (working on the GTR is painfull compared to the GTST)

I was wondering how would the RB26 respond to a small single turbo, enough that it will spool very early and not choke out at the redline. Is something like a single GT28 turbo feasable? or even borgwarner's EFR series? (6758 or 7064).

Or am I wrong for thinking that a small single setup would be much more responsive then a small twin? (2530s for example).

We will asume that the motor is going have a stock head and stock bottom end.

Thank you for your time and knowledge.

Edited by Idon28
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C4a0s Proficient

C4a0s

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erm... from my limited knowledge on the RB26... the stock twin piping is fairly simple compared to say a Supra's or a RX7's and u can replace the turbos with silghtly bigger ones which will give u damn good response and power..

most ppl go for single setup because of the huge power and big single turbo that cant fit in the existing space. so IMO going for single but yet small turbo...wouldnt really make much sense rite? remember.. for single turbo, u are feeding 6 cylinders...and not 3 now. =)

Idon28 Contributor

Idon28

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remember.. for single turbo, u are feeding 6 cylinders...and not 3 now. =)

Thats what I'm getting at. With 3 cylinders per turbo, that makes for 1.3L displacement per turbine.

Wont driving a turbine with 2.6L worth of exhaust flow (The whole engine) result in faster spool up on a properly sized turbine as opposed to two small turbos driven by 1.3L each?

Imagine twice the exhaust flow for single turbo instead of having to split it up for two.

The larger compressor can probably be matched to compensate for the airflow the twins did.

Edited by Idon28
C4a0s Proficient

C4a0s

Posted
Posted

yes u are right in mentioning abt exhaust flow feeding the turbine. however there are some real life physical limitations to consider....

exhaust flow and ability to compress air is not infinite nor are they linearly proportional throughout. there is an optimal amount of exhaust flow for every turbo such that once u exceed it, even if u give the turbo more exhaust, it can only spin that fast and compress that much air.

thus ppl go experimenting with hybrid turbos... switching and swapping compressors and turbines.

hope u find that sweet spot with the compressor and turbine for your purpose :)

MrStabby Grand Master

MrStabby

Posted
Posted

Thats what I'm getting at. With 3 cylinders per turbo, that makes for 1.3L displacement per turbine.

Wont driving a turbine with 2.6L worth of exhaust flow (The whole engine) result in faster spool up on a properly sized turbine as opposed to two small turbos driven by 1.3L each?

Imagine twice the exhaust flow for single turbo instead of having to split it up for two.

The larger compressor can probably be matched to compensate for the airflow the twins did.

If you put on a small single the engine will spool very quickly buy make very little power (much less than stock). There is no free lunch, whether single or twins you trade off spool for power. If you wanted max spool out of an RB26 you would get the stock turbos rebuild with steel wheels and get about 280kw.

34GeeTeeTee Grand Master

34GeeTeeTee

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Posted

I would suggest going with the likes of a FP HTA 3076 or 3582 as they are known to spool pretty early but still produce big power........ Inb4 Lithium :P

Lithium Grand Master

Lithium

Posted
Posted

Lol you can't send me to this thread and then say that :P

Seems like quite a bit of work to go to, but the likes of an EFR7064 on a twin scroll manifold would be immensely impressive on an RB26 in terms of spool and response - and should be capable of respectable power too, more power than the stock turbos but not much and in no way comparable with GT2530s in power.

I personally wouldn't go with anything smaller than a EFR7670 (or a FP3076HTA like what R34Geeteetee suggested) on an RB26 - the spool of those units would still be at worst comparable with the stock turbos, or much better than GT2530s but still give a good power improvement... just not as much as much as GT2530s, probably half way between the stockers and GT2530s.

If you want to compare flow wise with GT2530s then you really need to be looking at things like an EFR8374 or FP3582HTA which will spool a lot closer to the GT2530 (still more responsive).

  • 2 months later...
Idon28 Contributor

Idon28

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Sorry to revive this thread, but I had a further question. I've decided on the gameplan, the RB26 unit won't be going into an R chasis, but into something much lighter, so high horse is no longer a requirement. So with the power goal of 300HP (220KW). which turbo would give me that goal with the earliest fastest spool? the 6258 or 6758? those have the same exhaust housing, just different compressors (the 67 is bigger, and I think that will be needed to achive that power level with a single). Or will that 64 AR housing be way too restrictive, and should I go with the slightly bigger 7064 turbo? (either .83ar or 92ar housing, would they be about the same? with the 92 bieng twin scroll and the 83 bieng single entry?)

I would almost think an N/A RB30/26 would be the way to go, but I would like to have some upgradabity and low expense, so I think a turbo is the more logical choice.

Thank you.

Edited by Idon28

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