My Sr20 Build (part 2) Twin Scroll

[juggernaut1]

My previous setup copped the following upgrades:

3076 52 trim (replaced the 3071 56 trim);

Extrude honed exhaust housing;

3.5 inch C-Red custom dump and custom CES exhaust (replaced 3 inch ex)

Tial MVR wastegates smaller (replaced Tial 44 wastegates)

100 cpi cat with 5 inch body 3.5 inch in and out;

Gate dump merged back into exhaust just before the cat (previously merged just before it went under the car);

BP98 retune by Sean at Allstargarage.

Unfortunately I don't have back to back dyno's on the same dyno as the retune was done by a different tuner.

Will post up the boost graph when received.

Initial driving impressions - this feels more responsive than the previous 3071 setup. Peak hp is achieved at around 6350 rpm.

I suspect the boost control is a little wonky judging by the torque and hp graphs.

links to other threads:

Dyno's

http://www.skylinesaustralia.com/forums/Sr...l=my+sr20+build

Build Pics etc

http://www.skylinesaustralia.com/forums/Sr...l=my+sr20+build

Edited September 15, 2010 by juggernaut1

[R31Nismoid]

Nice results indeed.

Very interesting that the larger turbo is more responsive - when compared to the old graphs you can see it's clearly more responsive, no question! It's making an extra 40rwkw @ 3200rpm!!

Looks like the larger exhaust & new gate plumbing helped substancially.

What were the old parts removed? (just for info's sake, like what CAT was there etc?)

Any other boost controller alterations? (hard to tell if its more responsive without the graph yet hehe)

[STATUS]

Nice.

[Dale FZ1]

Looking good. I'd like to see the boost and AFR overlays.

What sort of muffler setup did you have fitted? And how is the noise level?

Just had a 3.5 inch system fitted to my R33, not droney or anti social so pretty good for every day use. Hurricane mufflers.

[juggernaut1]

  R31Nismoid said:

Nice results indeed.

Very interesting that the larger turbo is more responsive - when compared to the old graphs you can see it's clearly more responsive, no question! It's making an extra 40rwkw @ 3200rpm!!

Looks like the larger exhaust & new gate plumbing helped substancially.

What were the old parts removed? (just for info's sake, like what CAT was there etc?)

Any other boost controller alterations? (hard to tell if its more responsive without the graph yet hehe)

The old cat was a Metal Cat 4inch body with 3inch in and out. The old exhaust was a CES 3 inch exhaust from the cat back. The previous dump was a full-race motorsports dump with custom lower pipe.

No boost controller alterations

Yes I believe the larger 3.5 inch dump straight off the back of the turbo and introducing the gate pipes back into the exhaust just before the cat are can be attributable for the extra responsiveness. Josh at C-Red did an awesome job of the fabrication work - fitting a 3.5 inch dump and twin 44mm gate tubes in an SR engine bay is no mean feat. The 3.5 inch CES exhaust is also pure quality. In fact I would also suggest its no louder than their 3 inch system even with the 100cpi cat. The mufflers are 2 x large custom made in house at CES.

Edited September 15, 2010 by juggernaut1

[R31Nismoid]

It's made quite a massive difference, goes to show you can make the power with a tight exhaust, but changing it can still reap big benefits.

Be interesting to see the boost graph when its done - it looks like it's coming on at LEAST 500rpm sooner.

And for going to a larger turbo, gettting boost earlier - thats just fken win win win!

[juggernaut1]

  Dale FZ1 said:

Looking good. I'd like to see the boost and AFR overlays.

I was told it made 1.6 bar (23psi) at 3600rpm....which sounds plausable judging by the torque curve....which is awesome for a 3076 on a stock stroke SR

I'd like to see the boost graph though.

Edited September 15, 2010 by juggernaut1

[JonnoHR31]

that is awesome. out of curiosity which turbine housing are you using?

[juggernaut1]

  JonnoHR31 said:

that is awesome. out of curiosity which turbine housing are you using?

.78 ex hsg

[bradsm87]

Next step - 10:1 compression and E85 LOL. Imagine how responsive it'd be then! That's a good figure for 98RON. What cams? (I'm too lazy to search or look at old threads)

Edited September 16, 2010 by bradsm87

[juggernaut1]

Tomei 260/260 hydro cams....still using variable cam timing.

[Harey]

How can you come to the conclusion of what made the difference when a few things were changed?

Note the trim size, is a 3076 52 trim turbo bigger than a 3071 56 trim turbo?

[juggernaut1]

  Harey said:

How can you come to the conclusion of what made the difference when a few things were changed?

Note the trim size, is a 3076 52 trim turbo bigger than a 3071 56 trim turbo?

Yes, a 3076 52 trim turbo is slightly bigger than the 3071 56 trim.

Your right though, I can't conclusively say what did what....I don't even know what boost it was running on the dyno yet apart from that I was told it made 1.6 bar at 3600rpm.

All I do know is that I'm running a slightly bigger turbo and the car is definately more responsive throughout with the changes and the tune.

Perhaps this turbo is just more efficient at whatever boost it is running compared to the 3071?

Edited September 16, 2010 by juggernaut1

[R31Nismoid]

It's more than just a bit more efficient though, 40rwkw extra in some places has gotta be more than just a turbo change as the profiles from 52/56 are not "that" much different.

[Harey]

Yup but what if its running an extra 6psi in the midrange? I suppose even the speed that it can boost at is a big improvement.

Not trying to diss the results at all, I think they are great. I just think more investigation is required before understanding what caused the improvement.

[R31Nismoid]

You can tell whats caused it.

It's coming onto boost that much earlier though that it wont just be turbo - you don't get 40rwkw @ the same RPM (3200) as this is where boost is just ramping up if you look @ the old graphs and simple compare the torque/power curve. You don't need to see a boost plot to have a fair idea of whats going on.

Peak power/boost, I'm not really worried about here, its the huge improvement in response that is awesome.

It's all happening much much sooner that is more than just a turbo change that's for sure.

[discopotato03]

My guess is that a GT3037 52T turbo if it has the port shrouded comp housing should be a far better thing than a real GT3071R . Nismoid the only map I've ever seen of the GT37 52T compressor looks good , better in fact that the GT37 56T maps . Admittedly the 52T one I have is not a genuine Garrett map but the islands are vaguely similar to the 56T ones but moved 4-5 lbs further left .

The major change is the center island of highest efficiency - 78% and its wider that the 56Ts one .

Trim wise the 3071R and GT3037 52T are different - 56T and 52T . If you mean inducer diameter then its ~ 55mm for the 52T GT37 and 53.1mm for the 56T GT35 wheel (GT3071R) .

Don't be confused by my use of the the GT35 and GT37 compressor wheel families , they stem from the fact that those compressor wheels originally came from plain bearing GT diesel turbos and their turbines were GT35 and GT37 sized ones ie GT3571 and GT3776 .

A .

[R31Nismoid]

Do you think its worth 40rwkw @ 3200rpm though? Just as boost is ramping?

I know the centre is where the bigger difference is, but thats not whats more notable about this setup (not saying is less important etc)

[StealthX]

It's amazing what one can do with money...

[snozzle]

nice work dude, im much happier now that the 3071r is now gone haha