Gt35r ej207 tuning HELP

[cashrolling]

Hi guys. Need ur input on this. Just got my 2013 JDM spec C, it has a full setup to support the gt35r, but internals are stock. Car was tuned for safety. The tuner kept tourque at 352, and hp at 456. He explained to me he tuned it with low torque to keep the rods safe, therefore he played with the boost graph, meaning that he gets 20psi by 4800rpm, and slowly increasing boost to 26psi at 7500rpm, redline 8300( car has meth injection). Ha claims this is the safest way to tune it. I'm hearing different opinions on this. Would it be better have higher boost earlier and taper it down to the redline? Thanks for ur input.....

[Crispy 1]

Not if you want that motor to last any amount of time. He's keeping you from breaking a rod!

The way he tuned it is to keep cylinder pressures low (as low as possible with a 35r and 26psi) which will makes your rods much happier.

He is doing it right and keeping your stock bottom end together but with that much power it won't last for long no matter how it's tuned!

Good luck it sounds fun!

[subaru_gc8]

how does your car feel? a gt35 is going to spool super slow on a 2.0 liter anyways. so yeah if you don't like the tune get someone else to do it. what I know about the ej207, is it doesnt like alot of torque down low anyways. you could probably do more boost but you run the risk of lifting the heads after like after 28ish on stock head studs. so choose yoru poison. if you want to keep your engine running, dont go super crazy and try to push it to see what it will do.

[cashrolling]

The ej207 specC( the one I have) supposed to have different cams and stuff, actually it's not very laggy. By 4000rpm boost starts build and fast, B4 5000 fullboost in 3rd gear, then full power to 8000rpm. It's very nice.
About the tune, as I want it to last as long as possible, I'm going to lower the boost to 24psi, and keep it same way with lower boost at lower rpm and make it increase to redline.

[Fierysun]

Your tune doesn't sound right to me and the EJ207 rods doesn't have a strength issue below 500whp/wtq. Have your tuner redo the tune and make sure there isn't any knock anywhere in the RPM band.

[cashrolling]

Originally Posted by Fierysun

Your tune doesn't sound right to me and the EJ207 rods doesn't have a strength issue below 500whp/wtq. Have your tuner redo the tune and make sure there isn't any knock anywhere in the RPM band.

Please , I search but I seems to find differents infos. Help me understand the difference of my engine compare to a regular STI 207. To be more precise my car just imported from Japan, it's a 2013 STI spec C type RA, NBR challenge edition.
Can anyone explain the properties , weaknesses and strength of this engine compare to other similar version? I appreciate the help, don't really have time to spend hours searching the net.
About the tune it's very safe, no knock whatsoever.

[subaru_gc8]

Originally Posted by cashrolling

Please , I search but I seems to find differents infos. Help me understand the difference of my engine compare to a regular STI 207. To be more precise my car just imported from Japan, it's a 2013 STI spec C type RA, NBR challenge edition.
Can anyone explain the properties , weaknesses and strength of this engine compare to other similar version? I appreciate the help, don't really have time to spend hours searching the net.
About the tune it's very safe, no knock whatsoever.

most of the complaints are from the 205 not the 207. the 205 does have rods that are a tad weaker than the 207. 207 rods are the same the usdm sti got.. if you are really worried about strength, get the manley Hbeams and rebuild the block

Originally Posted by cashrolling

The ej207 specC( the one I have) supposed to have different cams and stuff, actually it's not very laggy. By 4000rpm boost starts build and fast, B4 5000 fullboost in 3rd gear, then full power to 8000rpm. It's very nice.
About the tune, as I want it to last as long as possible, I'm going to lower the boost to 24psi, and keep it same way with lower boost at lower rpm and make it increase to redline.

you should be fine with 24. if you are happy with the tune you have... dont worry about it. I have a 2.1 with v9 heads and my powerband doenst really come on til 3700 with the avcs working. 4200 without it

[fastnoypi]

what gen GT35r are you using and what fuel?

[cashrolling]

Originally Posted by fastnoypi

what gen GT35r are you using and what fuel?

The turbo was bought brand new 6 months ago. Was the best and newest available at that time,most expensive as well. We use 91 octane with water-meth injection

[motorbykemike]

Originally Posted by cashrolling

The turbo was bought brand new 6 months ago. Was the best and newest available at that time,most expensive as well. We use 91 octane with water-meth injection

how about a part number for that turbo ?

the box or the tag on the center section has it on it

[motorbykemike]

judging by the numbers (and meth) in the first post I'm guessing pump gas ?


2013 v10 sti ej207 should have very thick cyl walls , weak link would be pistons , then rods


sounds like his tuner is not a brotuner idiot

[subaru_gc8]

Originally Posted by motorbykemike

judging by the numbers (and meth) in the first post I'm guessing pump gas ?


2013 v10 sti ej207 should have very thick cyl walls , weak link would be pistons , then rods


sounds like his tuner is not a brotuner idiot

gt not gtx remember.. true ti doees have thick walls, but the 2-7 dont really make alot of power down low anyways

[motorbykemike]

Originally Posted by subaru_gc8

gt not gtx remember.. true ti doees have thick walls, but the 2-7 dont really make alot of power down low anyways

huh - eng rish pleas e - ?

[subaru_gc8]

Originally Posted by motorbykemike

huh - eng rish pleas e - ?

wow sorry for the spelling errors dang but if you cant figure it out here we go again he said it was a gt not a gtx so the spool will be slow. the 207 does have thick walls but it still a 2.0 and will spool that turbo super slow anyways....better??

[cashrolling]

Originally Posted by subaru_gc8

wow sorry for the spelling errors dang but if you cant figure it out here we go again he said it was a gt not a gtx so the spool will be slow. the 207 does have thick walls but it still a 2.0 and will spool that turbo super slow anyways....better??

Honestly it's not that slow. It's a ar63, and from 4200 it starts spool and fast. Actually I was surprised myself. Then I have progressive power all the way to 8000rpm..
But back to the topic, am I playing with fire here? Should I lower boost to 21psi to be safer? What u think of the way he tuned it, 20psi at full spool slowly increasing to 26psi to redline?

[cashrolling]

So, am I safe to keep boost the way it is? As now it spools fast at 21psi by 5000rpm, then slowly increase to 26psi at 7800. Should I lower the top boost to 23 or 24?
Yes. Pump 91 plus meth

[motorbykemike]

really depends on what version of the 35r you are using

it could flow from 54 to 87 lbs/min

that makes a difference because 20lbs of boost on one turbo is not the same as 20lbs on another

it's more about the air mass being moved

part number ?

it's usually the lower set of numbers on the tag on the center section on a garrett

[cashrolling]

Originally Posted by motorbykemike

really depends on what version of the 35r you are using

it could flow from 54 to 87 lbs/min

that makes a difference because 20lbs of boost on one turbo is not the same as 20lbs on another

it's more about the air mass being moved

part number ?

it's usually the lower set of numbers on the tag on the center section on a garrett

The turbo number is
706451-5008
Ljm026920

[86Dreams]

https://www.garrettmotion.com/racing...turbo/gt3582r/

look at the compressor map for yourself. compare boost vs airflow.

Tapering boost controls the speed of the compressor wheel.
Tapering becomes necessary when the compressor is at its limits.
However, consider the vertical line at 55lbs/min, if youre starting at like 20 psi and 30lbs/min at and run out to 55lbs then tapering and maintaining a constant compressor speed will push the turbo into a region that is less efficient than if it climbed up to about 26psi and 55lbs instead.

Efficiency is heat, so at 76% efficiency the air coming out of the turbo is cooler than at 66% efficiency.

[cashrolling]

Originally Posted by 86Dreams

https://www.garrettmotion.com/racing...turbo/gt3582r/

look at the compressor map for yourself. compare boost vs airflow.

Tapering boost controls the speed of the compressor wheel.
Tapering becomes necessary when the compressor is at its limits.
However, consider the vertical line at 55lbs/min, if youre starting at like 20 psi and 30lbs/min at and run out to 55lbs then tapering and maintaining a constant compressor speed will push the turbo into a region that is less efficient than if it climbed up to about 26psi and 55lbs instead.

Efficiency is heat, so at 76% efficiency the air coming out of the turbo is cooler than at 66% efficiency.

I'm not a big turbo expert, could u explain in a slightly easier way? This means that u agree with the tune?

About the rods, I thought ej207 had that weakness as well.....my bad, glad to hear it's stronger....

[86Dreams]

Originally Posted by cashrolling

I'm not a big turbo expert, could u explain in a slightly easier way? This means that u agree with the tune?

Did you look at the compressor map I linked? here is the compressor map anotated with axis lines and paths.
https://i.imgur.com/L7t85is.jpg

[cashrolling]

Originally Posted by 86Dreams

Did you look at the compressor map I linked? here is the compressor map anotated with axis lines and paths.
https://i.imgur.com/L7t85is.jpg

Thanks for the link. So to my understanding the tune I have is not that bad after all, I have limited torque at high load, to preserve the stock internals, and slowly increasing the boost for progressive power withing the turbo capabilities....

[subaru_gc8]

the 207 rods are the same as the 257, so not real weak but they arent h beams or i beams. you know even though you have a the engine you have, it is still a stock engine and it is a 2.0l and a 35r is a pretty sizable turbo. To me that it sounds about right as far as a 35r on a 2.0l. what ar turbine housing are you using? I ahve a 2.1 with V9 heads and with my gtx3067 I spool at 3700ish with a tial ,82 but i have power all the way to 8000 too. so yeah, I mean any way you look at it, its a 2.0 not a 2.5 or a 3.0 v6.
I do have a question, what gas are you using?

[cashrolling]

Originally Posted by subaru_gc8

the 207 rods are the same as the 257, so not real weak but they arent h beams or i beams. you know even though you have a the engine you have, it is still a stock engine and it is a 2.0l and a 35r is a pretty sizable turbo. To me that it sounds about right as far as a 35r on a 2.0l. what ar turbine housing are you using? I ahve a 2.1 with V9 heads and with my gtx3067 I spool at 3700ish with a tial ,82 but i have power all the way to 8000 too. so yeah, I mean any way you look at it, its a 2.0 not a 2.5 or a 3.0 v6.
I do have a question, what gas are you using?

I was looking into that same turbo. What's ur numbers like with it? I wouldn't mind an earlier spool as long as the power doesn't drop off at higher RPM...

[subaru_gc8]

Originally Posted by cashrolling

I was looking into that same turbo. What's ur numbers like with it? I wouldn't mind an earlier spool as long as the power doesn't drop off at higher RPM...

im tuned to 22 psi and 380 is what I have, it doesnt fall, on the top end, but the way it was explained to me is, if your turbo falls off you need a bigger hotside, basically it chokes the turbine housing so you need a bigger ar, but you suffer a little on the other end. mine seems to spool around 3700ish and goes all the way to 8000 but I do have a 2.1 so yeah might spool a little faster than a 2.0 not really sure. but really what i wanted was a fat power band and Im pretty happy with it. I mean its not the fastest but I can beat mustang and camaros all day long