Disco Potato (GT28RS) Spool Up

yes sir,no cats here.

Just the resonator that came with the corksport exhaust with, a magnaflow muffler instead of the corksport fart can...
 
Bump...I see full boost at like 3400. I'm only on 6 PSi though. I am catless with a CS exhaust and 2.14 DP. How does the tuning work for helping the turbo spool faster? Lean it out before boost I assume. Any thoughts to help in my setup.
 
LinuxRacr said:
Yeah, Alfredo, that's about where I see 5-6 PSI as well.

AAHHH NOOO...that's scuks wish I could make it spool faster though. I LOVE the speed of those T25. Would it be beneficial to get the RS wheel in a T25 housing. I guess that's the "Nick" upgrade.

Pat answer your phone pimp....(poke)

arlsmazdaspeed said:
Whats the max psi you can see with your set-up? tuned or untuned...

I run a Tial external wastegate and it has a 5.8 lb spring. So the max I see is 5.8 pounds. Just enough to get me 196whp and 194 wtq.:) (tuned)
 
avarela86 said:
AAHHH NOOO...that's scuks wish I could make it spool faster though. I LOVE the speed of those T25. Would it be beneficial to get the RS wheel in a T25 housing. I guess that's the "Nick" upgrade.

I'll attempt to word this to avoid all the nay-sayers....

to answer your question, yes and no. It really depends on what you want. In general, people assume that "bigger is better", when that is not always the case. The gt28rs is a great turbo, but at 6psi, your not doing it any justice. What are your plans for the car? Are you happy with its performance now? Do you plan on going forged soon? Is this a fun, daily driver, or a track car? Whats more important, peak power or responsiveness?

You do have a few options, but it really depends on what your plans for the car are. If you don't plan on going all out, then a different turbo may work better for you.

Personally, I would suggest looking for a .64 AR turbine (exhaust) housing. This will allow for quicker spool-up, and you'll reach full boost much sooner. It will also shift your powerband to lower-middle rpm range, rather than middle-upper as it is now. It will give you the quicker, peppy, no lag feeling you are looking for. Since the GT28rs has a bigger exhaust/turbine wheel, it wont be quite as fast spooling as the t25, but it will be noticably faster than what you have now.

If you do plan on going all out and doing a build-up, then you can always place the .86AR exhaust/turbine housing on then. The smaller turbine housing will limit your top-end power when you go all out and turn up the boost. I'll explain that later if you really want.

As for the modified "Nick" turbo upgrade... That is really up to you. You would have to purchase a MSP turbo, and then have Nick do the modification for $500. Not exactly cheap, but if you sell the 28rs, it should cover the cost. If you plan on going all out later down the road, you'll most likely find yourself buying the 28rs again. It will take more PSI on the Nick t25, to match the current power on the 28rs, but it should be a quicker car as peak power is hit sooner in the powerband. Its really your call though.

I say: start calling certified garrett dealers, or search ebay for the 28rs .64 AR housing. I have seen them on ebay a few rare times.

hope that helps a bit.
 
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Very well said Yashart. I have done the same research, and have found that this is probably what most want as far as turbo response. I loved the response from my GT28-R. Don't get me wrong, the 28-RS is great for the highway, but for everyday traffic, not as good as the GT28-R. The .64 turbine housings for the GT28-RS are around $200 on ATP Turbo last time I checked.

Note: The .64 turbine housing on the GT28-R is NOT interchangable with the GT28-RS.
 
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yashart_mp3 said:

Thanks Yashart for the info. I didn't know about being able to do that change in housing. I never even botherd to check which size housing I have. I plan
to build it but not shoot for BIG numbers. I will go to the Garret website and start looking at charts to see what the power range is.

LinuxRacr said:
Don't get me wrong, the 28-RS is great for the highway, but for everyday traffic, not as good as the GT28-R. The .64 turbine housings for the GT28-RS are around $200 on ATP Turbo last time I checked.

I checked and couldn't find just the .64 housing. I will keep it in mind like I mentioned to Yashart. I may stick to this turbo and do some head work and a larger exhaust to see if it helps with spool. It may be easier to make my desired power this way and plus I do MOSTLY highway driving.


Thanks for the input guys.
 
avarela86 said:
Thanks Yashart for the info. I didn't know about being able to do that change in housing. I never even botherd to check which size housing I have. I plan
to build it but not shoot for BIG numbers. I will go to the Garret website and start looking at charts to see what the power range is.



I checked and couldn't find just the .64 housing. I will keep it in mind like I mentioned to Yashart. I may stick to this turbo and do some head work and a larger exhaust to see if it helps with spool. It may be easier to make my desired power this way and plus I do MOSTLY highway driving.


Thanks for the input guys.

You have to call ATP for the price.
 
Last night I was hitting 10 PSI at 3500 RPM's instead of right before 4,000 due to a retune by JDM Sam, and myself. Full boost is 15 PSI.
 
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get some adjustable cam gears and dial out some of the valve over lap. that should help with spool up alot....you'd be surpised what only 2* valve overlap will do for you versus our stock 4* valve over lap.

One question, I have the stock msp turbo, and i was wondering if any of the internals were upgradeable...At the moment i'm looking for something like say a bigger compressor wheel that i can just drop in with out having to make any modifications like housings and such.

End thread jack.
 
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