***Topgunz ROTREX C38R Supercharger Kit***

14Q60awdSPORT

In light of COBB's recent announcement, and rumors of Ecutek to follow.

Any update on different pulley sizes?
I believe the changes may prevent the evap purge solenoid from being repurposed for controlling boost.

FrankEtier

Add a Wastegate and remove the need to control boost via the EVAP purge solenoid. I made this change and it seems to be more consistent.

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‘14 Topgunz Speedworks Rotrex Supercharged VR30 7AT 370Z Magma Red.
@liquid.magma

14Q60awdSPORT

That is a possible alternative people may have to do in the future if needing a tune/retune.


My setup has no issue holding 10psi low boost map or 11psi high boost map to redline at the moment. But good to know you aren’t getting boost creep on a wastegate.

cgr406

What wastegate are you using and where did you mount it? There's not much room in there!

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TopGunZ Rotrex SC / CJM RFS / 1300 / Ecutek / Dynosty / F.I. TP & CBE / Z1 / Swift / SPL / Whiteline / Hotchkis / Michelin SP4

FrankEtier

I don't have the specs on the wastegate with me but it is a Tial.

Attached Images

wastegate.jpg (66.1 KB, 36 views)

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‘14 Topgunz Speedworks Rotrex Supercharged VR30 7AT 370Z Magma Red.
@liquid.magma

cgr406

Thanks. I just got mine tuned @ Dynosty. I'm very happy w/ the power , but I'm definitely having the periodic power cut due to the safety factors in the tune, which Hal warned me might happen. The tune was just yesterday, so they've not yet had a chance to address it.

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TopGunZ Rotrex SC / CJM RFS / 1300 / Ecutek / Dynosty / F.I. TP & CBE / Z1 / Swift / SPL / Whiteline / Hotchkis / Michelin SP4

DrBacon

You may be better off with a fixed boost/pulley size anyways honestly. What you gain in low end torque from hitting peak boost earlier in the powerband you lose by decreased efficiency beyond that. This isn't a turbo where you are just bleeding off the excess wasted combustion anyways, you are making the engine work harder by spinning the supercharger at a certain rpm producing a specific CFM, by bleeding off the excess you are essentially wasting "work", also position of the wastegate/bypass valve matters as well, hopefully it's pre-intercooler.

14Q60awdSPORT

Yes that has always been my thought process, it does make 10lbs of boost by about 4k rpm whereas a 10psi pulley would only be making about 5.5psi at same rpm. So you’d end with same peak power but the current pulley setup will make way more power across the entire powerband.

Typically a general rule is 1psi add 6.7% more power but takes about 1.7% power away to create that psi with a supercharger. Generating 20+psi but only using 10psi isn’t very efficient but the supercharger spinning lets say 50k rpm with zero back pressure or in this case 10psi, is a lot easier than doing it against 20+ psi of back pressure so it’s not quite as inefficient as it initially seems, but still could be better optimized.

I always thought a 16psi pulley would be a good middle ground in still being able to hit about 10-11psi by 5500rpm and then flatline it only bleeding about 5psi at redline vs 13psi or so now.


I am already tuned so if I do retune it might be because of a built block and then I’ll be making max boost anyways. But who even knows timeline on if/when ecutek is following suit to COBB.

TopgunZ

Does anyone have a graph of a filtered vortech, or non filtered, on pump making 16psi and having a better power band? Bringing the boost in earlier gives you more power under the curve.

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ROTREX SUPERCHARGER TUNER KITS - $6799/ CUSTOM STILLEN AIR TO AIR KITS -$2100/ 700+ WHP!! WWW.TOPGUNSPEEDWORKS.COM

Dahawkster

I only come to this forum to check this very thread to see what this kit does on pump gas. I thought by now this thing would be over flowing with people's results.

FrankEtier

Been driving mine and fine tuning things since September last year. Going on dyno for some pulls next Saturday.

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‘14 Topgunz Speedworks Rotrex Supercharged VR30 7AT 370Z Magma Red.
@liquid.magma

VHRpurr

Where you headed for that? There’s not many VQ tuning shops in DFW unfortunately.

KarlKFI

Any word on CA legality?

Are you planning to submit for CARB exemption?

FrankEtier

A guy in Celina that has a shop. He focuses on Subaru but wrenches on pretty much anything and does general mechanic work. Not expecting any tuning from him just use of dyno for pulls. Ivan’s Performance Shop.

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‘14 Topgunz Speedworks Rotrex Supercharged VR30 7AT 370Z Magma Red.
@liquid.magma

TopgunZ

Here you go. This happened a couple days ago. 93 pump...600whp/500wtq just touching 16psi.

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ROTREX SUPERCHARGER TUNER KITS - $6799/ CUSTOM STILLEN AIR TO AIR KITS -$2100/ 700+ WHP!! WWW.TOPGUNSPEEDWORKS.COM