Greddy Twin-Turbo In Development

LiquidZ

I know for me, I want something with really quick spool time if I were to go turbo. I want an awesome low end for street driving, and an occaisional track day.

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Mitsuyager9

keep in mind if you have a manual trans then you can manipulate your powerband with the clutch to not have any lag if you are comfortable with your car (to a certain extent)

LiquidZ

I probably wouldn't be able to do that. I have never owned a turbo car.

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Brazilbro

having high compression will spool the 20g faster then if you where at 9.1 ish range. so i think that 16g would be really fast, probably hitting full boost at 3200rpm with the 20g at around 3600. You could always put the turbos that come stock on the 3000GT and have full boost at 2400rpm... would probably crap out though after 6k

Scribe

There is a lot of debate about whether the higher compression ratio significantly affects spool time. The short answer is, not really. The long answer is, higher compression will give you better off boost performance until you hit boost. Also the extra heat from compression causing additional pressure in the exhaust manifold to spool the turbo has to be significantly higher from a pressure ratio standpoint to make a significant difference, but that doesn't happen to that extent.

westpak

I agree there are a lot of technical mumbo jumbo that can be thrown around, but from personal experience going from the stock 10.3 CR on my 350Z to 8.8 CR on the built engine my butt did not notice any change in efficiency, boost kicks in hard and early breaking tires lose in 1st through 3rd gear and still scary in 4th

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Sharif@Forged

20G's are used all the time on the 350Z. We've run even larger turbos on the VQ37 VVEL, and I promise you spool up and powerband isn't going to be an issue. Keep in mind, all of these turbos kits are using very small T25'ish sized flanges, so exhaust gas velocity isn't much of an issue.

I would much rather take the larger 20G over the more restrictive 18G. Compressor charts only tell you so much, but power output and spool vary drastically based on the application you are putting the turbocharger on.

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Sharif@Forgedperformance.com
General Manager/Certified Tuner/NASA-PCA-BMWCAA Instructor
JRZ RS1's Available NOW...PM me
Cobb ProTuner, Uprev ECU Flash, FCON Vpro, Haltech, Motec Certified

LiquidZ

How do the more turbo savy people here feel about the 20G and its journal bearings? I'm no expert, but people have convinced be that ball bearings are always better for turbos.

Thoughts?

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Mitsuyager9

ball bearing is always going to be faster on spool up but is more expensive than journal bearing...it all comes down to how much more do u want to spend for minimal performance gains..ball bearing will give you more of a crisp spool

Sharif@Forged

The spooling benifets of BB vs. journal are vastly overstated, IMHO. It's the size and structure of the turbo, and the displacement of the engine that has a much greater impact on turbocharger spoolup characteristics.

We just had a BB turbocharger on XKR's car take a dump after 3000 miles. Garret could not determine the cause of the failure. With Greddy, I have had modified turbos go bad, but haven't had any factory Greddy turbos go bad.

I am not suggesting that journal is more reliable than BB, but I am stating my experience to show that textbook discussions, can vary wildely from practical experience and application.

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Sharif@Forgedperformance.com
General Manager/Certified Tuner/NASA-PCA-BMWCAA Instructor
JRZ RS1's Available NOW...PM me
Cobb ProTuner, Uprev ECU Flash, FCON Vpro, Haltech, Motec Certified

LiquidZ

Thank you for that reply!

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fstrnldr

Sharif if people want a SC set up why argue? just build them one!



i agree i would personally rather have a turbo set up, but nothing wrong w/ a good supercharger.

Shunya

anymore news or updates on these?

CCCLXXZ

just finished initial dyno tuning of the twin TD06-20G Tuner Turbo kit. 450hp 370! The test drive feels good too!!!

about 3 hours ago from web (Greddy Twitter)

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Mods - Maxim Works Exhaust Manifold, FI HFC, Mines Y-Pipe, Saclam Silencer

LiquidZ

Good find.

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