Built Rb26 Turbo Selection For Drift

[Harey]

I haven't been in a Skyline with a TS GT35R *yet* but given they are a 6, the gains are only going to be at least as good as the 4cyl ones I've been in.

After reading one of discopotato's long posts twin scroll is more effective on 4 cylinder engines and less so on 6 cylinders and almost not worth it on an 8 cylinder. Sure it will be helpful on a 6 but I dont think the statement that it will be at least as good as a 4 cylinder is correct.

[Lithium]

After reading one of discopotato's long posts twin scroll is more effective on 4 cylinder engines and less so on 6 cylinders and almost not worth it on an 8 cylinder. Sure it will be helpful on a 6 but I dont think the statement that it will be at least as good as a 4 cylinder is correct.

There is probably a certain amount of theorising with both of our viewpoints, how do you decide he is more correct than I (or vice versa for that matter? I am happy to stay objective...)?

A lot of that will depend on the execution of the whole thing, for example on a V8 - where is the rationale that twin scroll would be less beneficial on a V8 than it would on a 4cyl when a V8 is essentially two 4cylinders? I wrote a big rant ages ago on GTR UK forum regarding the potential benefits of twin twinscroll turbos on a cross plane V8 to combat the effect of the unevenly spaced ignition events on each bank.

Also, I have been in Nissans running twin scroll turbos - just on a TS GT35R to compare with the exact equivalent single entry GT35R... hence restraining opinion. Given Disco doesn't sound like he can provide the same comparison, I'd consider it reckless stating a fact without confirming the theory.

[STATUS]

This is the only one i have handy (ie on this comp), full owner built car him and his old man did a great job, went on the dyno with no issues (other than bit of boost creep from the 6 boost mani)

The power graph is not really a good example as the boost curve starts at 14psi and tapers up to the 19psi point, not enough gate pressure but until the owner gets used to it we wont dial it up (the blitz gate and blitz i-color will dial it out a piece of piss).

If it was making the full 19psi by 3600-3800 like the normally do the they make around 220rwkw @ 4k and 270-280rwkw @ 5k etc... with the ramp rate i use, maybe more responsive on a roller.

[Harey]

There is probably a certain amount of theorising with both of our viewpoints, how do you decide he is more correct than I (or vice versa for that matter? I am happy to stay objective...)?

A lot of that will depend on the execution of the whole thing, for example on a V8 - where is the rationale that twin scroll would be less beneficial on a V8 than it would on a 4cyl when a V8 is essentially two 4cylinders? I wrote a big rant ages ago on GTR UK forum regarding the potential benefits of twin twinscroll turbos on a cross plane V8 to combat the effect of the unevenly spaced ignition events on each bank.

Also, I have been in Nissans running twin scroll turbos - just on a TS GT35R to compare with the exact equivalent single entry GT35R... hence restraining opinion. Given Disco doesn't sound like he can provide the same comparison, I'd consider it reckless stating a fact without confirming the theory.

Are you going up against the mighty discopotato!

Have you seen the length of his posts??

As we all know length DOES count...

[SimonR32]

This is the only one i have handy (ie on this comp), full owner built car him and his old man did a great job, went on the dyno with no issues (other than bit of boost creep from the 6 boost mani)

The power graph is not really a good example as the boost curve starts at 14psi and tapers up to the 19psi point, not enough gate pressure but until the owner gets used to it we wont dial it up (the blitz gate and blitz i-color will dial it out a piece of piss).

If it was making the full 19psi by 3600-3800 like the normally do the they make around 220rwkw @ 4k and 270-280rwkw @ 5k etc... with the ramp rate i use, maybe more responsive on a roller.

That is fairly impressive considering the boost issue!

Is that a T3 10cm flanged turbo or a 8cm Mitsubishi flange?!?

Also how much do you think a standard manifold would strangle through mid range and top end?!?

[Lithium]

After years of discovering most people read key words and assume they know what you were saying and having to reiterate or explain things, I am quite a lot lazier about what I say now If someone decides I might possibly have something worth sharing or elaborating on and ask, I will.

[XRATED]

This is the only one i have handy (ie on this comp), full owner built car him and his old man did a great job, went on the dyno with no issues (other than bit of boost creep from the 6 boost mani)

The power graph is not really a good example as the boost curve starts at 14psi and tapers up to the 19psi point, not enough gate pressure but until the owner gets used to it we wont dial it up (the blitz gate and blitz i-color will dial it out a piece of piss).

If it was making the full 19psi by 3600-3800 like the normally do the they make around 220rwkw @ 4k and 270-280rwkw @ 5k etc... with the ramp rate i use, maybe more responsive on a roller.

Nice power delivery... will be even better with the boost corrections as you mentioned.

thanks for putting up the chart.

Cheers

Justin

[Lithium]

+1, really good to see a dyno plot for one of those finally - had always wanted to see what they behave like.... very nice result.

[RBceffy25]

Awesome!

Thanks Trent! Thats what I wanted to see!

does that set up use the ebay turbo? Does it have cams?

How would a HKS 3037 pro S .68 rear compare to this in regard to response and top end power?

[limpus]

3037 Pro S is the same as a garrett 3076r but with hks specific housings...i'd go with the 0.87 turbine housing instead though...and like others have said...a really good match for lowish 300kws...

[RBceffy25]

Trent-

Does that owner built car have cams?

If not how much would a set of poncams affect this particular set-up in terms of response?

Its fairly identical to my what my set-up will be aside from poncams, standard/front facing plenum, Haltech. (possibility of ITB's)

Basis of the build will be a long motor from Darren Lewis, Lewis Engines.

Edited October 19, 2010 by RBceffy25

[RBceffy25]

At the end of the day I don't think any other turbo kit will come close to this sort of response and power figures for a $1000 flat, delivered to my door incl. custom lines to suit RB25 and fittings and all gaskets required for install.

Looks like its off to ebay!

Also, can anyone tell me what size wastegate would be ideal for between 17-22 psi on this turbo? (T67 10cm)

[l0WRB]

50mm

[RBceffy25]

50mm

Bit big maybe? probably better suited to running stock boost, which defeats the purpose of the whole exercise.

I think most people with similar sized turbo with similar boost levels seem to be running anything from 38mm to 44mm.

I was thinking 40mm?

[zebra]

Grab a 44mm tial, big enough but no too big, always best to err on the large side with these things imo

[RBceffy25]

Grab a 44mm tial, big enough but no too big, always best to err on the large side with these things imo

No worries.

So would you say then that the difference between 40mm-44mm, at these boost levels, would be negligible?

Cheers in advance for all the advice.

[battery]

At the end of the day I don't think any other turbo kit will come close to this sort of response and power figures for a $1000 flat, delivered to my door incl. custom lines to suit RB25 and fittings and all gaskets required for install.

Looks like its off to ebay!

Also, can anyone tell me what size wastegate would be ideal for between 17-22 psi on this turbo? (T67 10cm)

yeh i'd like to give one of these a go on my rb25 too.

but what manifold are you going to be using? you won't get it on the stock one without a spacer and its gonna be restricted up top....

a 6 boost would be nice but not at $1400!!! then at the other end you got the nasty china junk for $200 that won't last a week, is there any alternative for highmount manifolds around the $800 range?

[RBceffy25]

yeh i'd like to give one of these a go on my rb25 too.

but what manifold are you going to be using? you won't get it on the stock one without a spacer and its gonna be restricted up top....

a 6 boost would be nice but not at $1400!!! then at the other end you got the nasty china junk for $200 that won't last a week, is there any alternative for highmount manifolds around the $800 range?

I thought they were $1250 from Kyle(6boost)?

Regardless of price, I will be using 6boost low mount with 44mm external gate. same manifold in the photo from Trent. If you are not willing to fork out for a proper, high quality, tuned length

manifold then I suggest you use a second hand TRUST item with a Mitsubishi/trust style flanged turbo (you can still find full kits for RB engines w/ turbo, manifold, wastegate and dump pipe) or try to track down a HKS cast item. Your only other option would be a custom log or un-tuned high-mount manifold, which I would think would be in your price range. If your handy with a bit of welding, you could have a go at making one your self, using steam pipe bends from any gas fitting place. Anything else in your price range is simply not worth pissing on. Do it once, do it right I say. If i were you I would just save the extra and get the 6boost. The benefits far out weigh the cost.

Hope this helps!

[Mushroom]

I had a GT35r on my RB25 and found it to be really good, Fineline is another person on here that has as well.

We both made 500+hp atw out of them and mine was nice and progressive, I would have to search for a dyno sheet but.

[RBceffy25]

I had a GT35r on my RB25 and found it to be really good, Fineline is another person on here that has as well.

We both made 500+hp atw out of them and mine was nice and progressive, I would have to search for a dyno sheet but.

What size turbine housing?