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Eventually, after I get my Limited slip; I want to upgrade my turbo. The key part to this however, I don't want to lose the feel of the stock turbo. I love the instant punch it delivers, I just want a little more oomph.

This is my daily driver, however I also want to increase the the fun factor on my toy while keeping the stock fuel system. The gtx2867r is what most people here go, but I feel that the increase in turbo lag and pushing the stock fuel system to it's limits will make me regret the new turbo.
 

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I have the same goals and I think I'll go with gtx2860r gen 2
 

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Get the GTX2860r
 

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GTX2860 Gen II, .86 housing free float (no wastegate flapper)
Tial MVS External Wastage kit with "Screamer Pipe"

*Assuming you are already at FBO/Stage 3

There some attention to detail stuff I won't mention but this will spool quite nicely but not cut-off power up top like a .64 housing will. The external gate is to hold 28-30 psi to redline/fuel cut.

This is a max effort GTX28xx, add a few more pieces and it will embarrass 95% of the cars on the road.
 

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What would be the difference in spool RPM between .64 and .86?
 

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What would be the difference in spool RPM between .64 and .86?
100-150 rpm. It spools quick enough, no need to run the tight housing on it. It will make better power up top with the larger housing and tiny loss of spool.
 

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Actually the free float V band housing is .72 A/R Flow will still be better at higher RPM than with the wastegated .64

I haven't tried it or know anybody who has so take it with a grain of salt, not sure if your stock style downpipes will work so you might have to stick with the wastegated housings, but there's a solution for that anyway.
 

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GTX2860 Gen II, .86 housing free float (no wastegate flapper)
Tial MVS External Wastage kit with "Screamer Pipe"

*Assuming you are already at FBO/Stage 3

There some attention to detail stuff I won't mention but this will spool quite nicely but not cut-off power up top like a .64 housing will. The external gate is to hold 28-30 psi to redline/fuel cut.

This is a max effort GTX28xx, add a few more pieces and it will embarrass 95% of the cars on the road.
The vast majority of this went over my head. Down time at work is good for learning about non work related things.

Sent from my SM-G930V using Tapatalk
 

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It's easy to understand...

If you look at the turbine map of a GTX28xx turbo you'll see the .64 wastegated turbine housing is the most restrictive. At higher rpm it will cause too much backpressure in the turbo system leading to reduced power, unable to hold boost to redline/fuel cut, etc.

The .86 A/R housing is the least restrictive.

With a less restrictive housing an internal wastegate .86 A/R might hold to 7000 rpm, since most tunes set the limiter to 7200. The stock cams will start to level off around 6000.

FBO = Full Bolt-Ons

Max effort means -

Attention to details...
 

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It's easy to understand...

If you look at the turbine map of a GTX28xx turbo you'll see the .64 wastegated turbine housing is the most restrictive. At higher rpm it will cause too much backpressure in the turbo system leading to reduced power, unable to hold boost to redline/fuel cut, etc.

The .86 A/R housing is the least restrictive.

With a less restrictive housing an internal wastegate .86 A/R might hold to 7000 rpm, since most tunes set the limiter to 7200. The stock cams will start to level off around 6000.

FBO = Full Bolt-Ons

Max effort means -

Attention to details...
Don't want to clog this thread. I might PM you.

Sent from my SM-G930V using Tapatalk
 

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Why would it clog the thread?

If all you want is a little more power why is nitrous oxide being ignored?

Why is the next statement I like the stock turbo but want more power?

Both Little and More are undefined.

More than what? 1hp is more than what your car is currently making...

Is a little 10 more hp or 15 more?

Nitrous is the cheapest 70 hp out there. A nitrous powered stock turbo car is still the highest output stock turbo car (315 hp) and he did that on 91 octane. It would have made more on better fuel since the car limited ignition timing as he was running the Cobb Stage 3 OTS map. If you don't live your life "A 1/4 mile at a time" a 10 lbs bottle will last you quite awhile.

There was a national shortage in 2015 that carried over into 2016 but I haven't heard anything lately. Last time I filled up it cost me $65. You'll learn to be more judicious with it as time goes on.

That is a real option that is not being considered, why?

Next is the Pumaspeed X37 I think it's called. It's an upgrade based around the stock turbo. If you really like the stock turbo then this might be the route to go.

Max output of the Pumaspeed is about 370 hp, so let's do the math = $17.14 per 1 hp (70 hp gain) *Not including shipping from the UK

Careful shopping will net you a ATP GTX2860 Gen II for $1995 but then you need a BOV ($180) and a stainless steel flange ($20) for a total of $2195 not including paying somebody to weld the flange on, which cost me $50 locally ($2245). You can easily get 400hp out of that on the stock fuel system = $22.45 per 1 hp (100 hp gain).

I'd say max power is around 420-430 hp @28-29 psi = $17.26 per hp (130 hp gain)

After that you then must -

  • Prevent as much as possible the center of gravity shifting rearward at launch
  • Prevent the clutch from dragging rpm down at full engagement
  • Tune for low traction senarios IE street driving
  • Have some fun = (Wanna Go Fast, Street Car Takeover, Import Face-off, Racewaz, etc)

I am working on a traction solution and I want to test it first before I spill the beans.
 

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N2O is a blast especially on a DD car. And if your spraying 70hp worth your prob adding over 100ft/lbs of torque.
 

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N2O is a blast especially on a DD car. And if your spraying 70hp worth your prob adding over 100ft/lbs of torque.
35 hp shot with the stock turbo is the easiest and cheapest 70 hp gain. 70 hp shot on the stock turbo? If you turn it down to maybe 18 psi.

Since my preload isn't right I only get 18 psi max out of my GTX3071, so I can run 75 hp shot if I want. The problem is the stock clutch won't take it.
 

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35 hp shot with the stock turbo is the easiest and cheapest 70 hp gain. 70 hp shot on the stock turbo? If you turn it down to maybe 18 psi.

Since my preload isn't right I only get 18 psi max out of my GTX3071, so I can run 75 hp shot if I want. The problem is the stock clutch won't take it.
I was just trying to say that the torque gains with nitrous are even more impressive than the HP gains. I’m just guessing that spraying 70 HP worth of nitrous would prob get you an increase of 100ft/lbs of torque too. I’ve never used it on a boosted car though so idk how it differs from an N/a motor.
 

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I was just trying to say that the torque gains with nitrous are even more impressive than the HP gains. I’m just guessing that spraying 70 HP worth of nitrous would prob get you an increase of 100ft/lbs of torque too. I’ve never used it on a boosted car though so idk how it differs from an N/a motor.
Torque gains are impressive as well.


A friend of mine's AWD automatic DSM

Runs 100 hp shot to get the car on the converter but leaves it on the entire way

 
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