For you on a 2.4L I think the GTX3076R with a .63 will work pretty well... 71 will be a bit small and you have the displacement to make the 76 resposive...

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car is now over 400whp.. still upping boost tho. my goal is 500 with this car, no idea if we will reach it or not. only running 93oct for now. actually tuning it right now.

 

I thought I would provide an update although the car has not been boost tuned since installing the base map. All tuning is using 93octane and please keep in mind this is a bone stock motor with stock intake/tb as well as stock cams. Obviously the whole exhaust was modified as well as everything pre TB.

We started by dialing in the new 1000cc injectors for idle/cruise, which was accomplished after several logs. We then proceeded by setting the intial boost level. I have finally reached the desired boost level of 30-31psi on pump gas and the car runs very smooth. I am having zero knock, but the fuel is conservative. When I return from business travel we can begin the actual tuning process.

At this point it would make no sense to post graphs until Tom has worked his magic, but as the car sits the turbo generates 27psi@5Krpm in 3rd gear. I will let you draw your own conclusion, but the 0.63a/r is likely a better choice for my setup. I hope to post some Virtual Dyno graphs within the coming days.

 

stupid question but what was it like in 1st and 2nd?

 

^
Are you referring to boost response? If so I have not logged, but I can say in 5th gear it sees 27psi@4200rpm.

 

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yes i was referring to the boost and power.

if you could do me a favor, the next time you tune it, log and/or take note of the response in 1st, 2nd, and 3rd gear i would really appreciate it

 

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I will gladly provide those logs, but I think it makes more sense to do so following the tune.

 

Nice work mate.
Friend of mine just had his stock SR20 setup with mild cams tuned with a tubular manifold and 0.63 rear GTX3076. It hits ~24psi by 4100-4200 on 92 pump.

 

Beautiful work!!!

 

Thank you. I think I should provide an update for the project. I started the initial tune with Tom, but quickly realized I might have issues so we stopped. The car hit a wall and increasing boost only improved mid range torque/hp, but not top end power.

My first suspicion was the wastegate dump tube being recirculated might be robbing power. However, I tested the theory on my current setup and found the open dump had little/no affect on hp/torque. See pics below.




My next test will be to removed the 3" exhaust that uses an aftermarket CAT and place a down tube directly at the end of the downpipe. If the hp/torque increase then I know the CAT is the issue. The test is quick and dirty and I hope to test this tomorrow night.

In the interim, I have received the new 0.63 a/r housing because 0.82 a/r housing is too laggy in my opinion getting 27psi@~5Krpm in 3rd gear. I think on a motor with a good head/cams and more displacement the larger housing would work out well. I hope to swap the a/r this weekend so I will have good comparative data for spool vs. a/r for this setup.

While the new a/r is being changed I will mockup my new strategy for the T4 twinscroll, which will be a short runner design. The initial runners are being mocked up at different spacings off the flange so I can first determine the necessary position so this thing will fit. However, the intent is indeed to have the runners short. I don't think it will be an optimal race design, but I do think the short runner TS would work well for a DD or street/strip applications. I plan to utilize slip joints when connecting the remaining two runners to minimize the potential for cracking.

 

I hope it's not the revhard mani causing you trouble. I'm trying to finish up my build with one of these mani's too. The big difference is the progress you make in days, is my progress done over months. My cars been down for a year now Keep up the good work

 

I don't suspect the manifold is the cause in my case and at my power levels as I have seen others making good power with this manifold. Below is an example.

https://www.evolutionm.net/forums/ve...bo-review.html

 

I think this might just work out well. Spacing is great and almost lines up with the existing RevHard setup. This is a 1.06 T4 TS turbine housing and there is plenty of room for a 3" downpipe.

 

Here are the results of swapping from the 0.82a/r to the 0.63a/r turbine housings. No other changes were made except swapping housings.



I will remove the CAT later today to see if this is the cause of my restriction. I gained about 400rpm of spool with the smaller housing.

 

Wow, this is interesting. I removed the exhaust after the downpipe and installed a turndown so it is a 3" open exhaust. So what were the results...

Only +9hp/+4ft/lbs