Garrett Medium Frame Gtx Turbos

[ARTZ]

No.its not. Lol. At 600hp yes. But 3" Turbo Back is enough at this power surely The cat Is highflowed to 3" too. So id assume thats ok. I have 4" intake. That's fine. What else is.there?

you have a 4 inch intake sucking through a 3 inch afm..so effectively you have a 3 inch intake..

what do you mean the cat is highflowed? if you mean its gutted then it should be ok, if you mean its a 3inch hiflow cat then it means nothing, it is way too small to flow properly, other are running 4 and 5 inch cats

it may be at low boost buts its still a big turbo trying to move a large volume of air through a small hose. So

effectively you have a huge air pump with small ducting and its not happy..

[ARTZ]

think of it this way..

2 turbos one big one small pumping the same amount of air..

the small one pumps fast and hard to move x amount of air so it can suck it through a smaller hose cause the velocity is up..

a big turbo will easily pump the same amount of air but slower..so when it goes to breathe it needs big pipes to move all that air at a lesser velocity otherwise its just choking..

add to that and it cant get the air out quick enough through a 2 1/4 inch pipe with 4 90 degree bends in it and this is why you have no power until it gets to 4000rpm and the air has some velocity behind it..at the moment the air cant get in,out or through at the required rate to make it work..

I dunno if that makes sense but i really think it could be a big part of your problem

note..

(if somone with more experience wants to tell me Im wrong go for it )

[ShiftyTys]

you have a 4 inch intake sucking through a 3 inch afm..so effectively you have a 3 inch intake..

what do you mean the cat is highflowed? if you mean its gutted then it should be ok, if you mean its a 3inch hiflow cat then it means nothing, it is way too small to flow properly, other are running 4 and 5 inch cats

it may be at low boost buts its still a big turbo trying to move a large volume of air through a small hose. So

effectively you have a huge air pump with small ducting and its not happy..

I believe the afm is like 3 1/4 " or sumthing. Plus I've gutted the afm. No 1" bar across the middle. Most people run pfc with an afm Which still has an inch of thick plastic to create turbulance etc. I duno. Look ideally Wed all have no pod filter and almost zero exhaust for altimate flow. Lol. If I can get 500rpm off with actuator fiddling etc. This will be an insane setup. 600hp full boost at 3500. That's like hard to even comprehend. Lol

[ShiftyTys]

think of it this way..

2 turbos one big one small pumping the same amount of air..

the small one pumps fast and hard to move x amount of air so it can suck it through a smaller hose cause the velocity is up..

a big turbo will easily pump the same amount of air but slower..so when it goes to breathe it needs big pipes to move all that air at a lesser velocity otherwise its just choking..

add to that and it cant get the air out quick enough through a 2 1/4 inch pipe with 4 90 degree bends in it and this is why you have no power until it gets to 4000rpm and the air has some velocity behind it..at the moment the air cant get in,out or through at the required rate to make it work..

I dunno if that makes sense but i really think it could be a big part of your problem

note..

(if somone with more experience wants to tell me Im wrong go for it )

I get what your saying. Before I go repiping etc ill see if actuator and nvcs can Get me to 3500. I think everyone agrees 3500 on this Turbo with this power potential is great.

Edited July 1, 2011 by ShiftyTys

[GTScotT]

Generally a cat with 3inch flanges will have a 4 or 5 inch body.. You will not see many cats that are simply in a pipe section, that do not flare out.

[SS8_Gohan]

we dropped the exhaust one time on my GT-T between dyno runs, made bugger all difference - a good highflow cat that retains a 3" diametre (not talking about body cat size) through the whole system should be fine

[ShiftyTys]

we dropped the exhaust one time on my GT-T between dyno runs, made bugger all difference - a good highflow cat that retains a 3" diametre (not talking about body cat size) through the whole system should be fine

Exactly. Clearly the cat diameter is the outside size of the cat pretty much. When they high flowed mine the actually just changed the in and out pipe to 3".so now I have a min of 3" through my whole system. Also my cat cell count isn't bad either. From what I've been told.

[BMYHOE]

we dropped the exhaust one time on my GT-T between dyno runs, made bugger all difference - a good highflow cat that retains a 3" diametre (not talking about body cat size) through the whole system should be fine

yeah what turbo where you using?

[R31Nismoid]

A 3" CAT on 270-300rwkw setup is a restriction.

Even with 270rwkw and -9s, when i take the CAT out of my GTS-R i can feel a difference and it's either a 4 or 4.5" CATCO item.

Not so much in outright power noticeable, but just throttle etc. Stuff you dont see on a dyno

[ShiftyTys]

A 3" CAT on 270-300rwkw setup is a restriction.

Even with 270rwkw and -9s, when i take the CAT out of my GTS-R i can feel a difference and it's either a 4 or 4.5" CATCO item.

Not so much in outright power noticeable, but just throttle etc. Stuff you dont see on a dyno

So your saying 3" into knocked out cat ( say I knock it out) is still not good enough?

[ARTZ]

so you have the standard cat with modified pipes or a whole new cat?

anyway Im more concerned with your intake pipes than the cat, but if someone tells me there running big power through standard cooler piping I will let it go

[Rolls]

I really doubt the cooler piping makes a huge difference, the vac side of the turbo as it isnt under pressure I can see making a bit of diff.

Anyone changed stuff like this back to back, if so what was the difference?

[ShiftyTys]

I really doubt the cooler piping makes a huge difference, the vac side of the turbo as it isnt under pressure I can see making a bit of diff.

Anyone changed stuff like this back to back, if so what was the difference?

+1 for some back.to back.info

[Rolls]

Yeah there is always lots of theory going around but real world results win hands down, I've always been sceptical of how much difference the size of cooler and intake piping makes.

[ShiftyTys]

Yeah there is always lots of theory going around but real world results win hands down, I've always been sceptical of how much difference the size of cooler and intake piping makes.

Lee from avo had same intercooler. And I think a 1/4 inch larger piping on his r33 gtst race car. Was sitting on 370 something rwkw.

[scotty nm35]

Im pretty pleased with the tune tonight at Edge Motorworks, power wise a little less than I was aiming with the stock exhaust manifolds holding me back I would say but i'm amazed at the torque the little VQ25det's making. (more than the 470kw T88 supra they had just done apparently) We ran the GTX3071 up to 25psi falling to 21 by redline, it still felt like it had plenty left in it but a few issues came up. (cooler joiner blew off and we also hit 85 percent duty on the 1000's.)

The graph doesn't relate at all to what an RB would do with this turbo seeing mine is a V6, AWD auto but it definitely shows promise. The transient response when over 4000 revs is extremely fast, it spools in half the time the old bush core highflow did. The 1.06 rear really helps with the off boost power too, it may seem obvious to some but I wasn't expecting to gain anything down there. Also a great result considering I run the Emanage Ultimate imo. The car drive amazingly well now for a 2tonne barge.

[Rolls]

Lee from avo had same intercooler. And I think a 1/4 inch larger piping on his r33 gtst race car. Was sitting on 370 something rwkw.

Im sure but Im curious what difference changing the pipe size makes, eg a lot, or bugger all.

[GTScotT]

Good work scotty, thats a great result. The EMU is not as bad an ecu as you may think, JZ guys use them for anything sub insane.

Specifically, despite the fact your motor outflows an RB to hell and back, to see the turbo standing up (where I expect 4k to be) and making over 200kw of midrange, with a final output of roughly 300 I have to say WIN. 200kw @ 4k rpm and 300kw peak is the best of both worlds as far as RB25's go (again knowing that you dont have one), its like having a GTRS and a 3037 (3076R) all in one.

Good work champ.

[scotty nm35]

Thanks Scott. Its great knowing its all my own work too.

I just wish there was an awd manual option for me, the torque converter isn't happy at all, the lockup clutch was slipping badly hence the wavy power curve.

[Rolls]

I thought it only locked up under low load?