High Flowed -7s Vs -9s

[No Crust Racing]

Hoping to wind up with around 330 or so rwkw in a 34, have been looking at turbos.

I've come across the turbo setup from the Motive DVD R32, they are apparently -7 housings machined to fit -5 ball bearing internals.

I can see from the clips that they ended up making 380 plus on e85, but the steps they did the mods in didn't give me a good idea of they'd make on pump as they did the fuel system when the pump maxed out around 300rwkw.

With stock cams and adjustable gears, car also has PowerFC L-Jet, which would be better in terms of response, which would be better in terms of max power?

I realise there's a lot of guess work but I was hoping someone else has high flowed -7s before but I can't seem to find much with the search.

[gtr jet]

So I take it your planning on sticking to 98?

I'd probably go with the -9's if that's the case. You'll make your 330 with less lag than high flowed -7's.

[No Crust Racing]

Most likely as there's no e85 at the pump here so I'd have toi get it in barrels which is expensive if bought from local suppliers or a bit of work if I get it from Melbourne and bring it back.

[breaker1845]

High flowed -7's with the -5 internals would be the winner in terms of power but not response. It's a tricky combination and its rarely done due to costs, so if you bought second hand getting them inspected would be a good check.

If you didn't want to go with those, off the shelf -9's or HKS GT-SS would be your next best option. They are very responsive turbos and will deliver the power you want (330 ish), however the -7/-5 combination would only just out perform them in power.

My suggestion would be to get the -9's for the 330kw range power and better response. If you wanted to go e85 at some stage, they can push more at higher boost levels.

I don't know how well the -7/-5 combination works on pump 98 though, so might want to shoot Andrew Hawkins a pm or something about that.

-9's are great turbos, and with stock cams and adjustable gears, you'll be able to achieve the power you want with great response.

[No Crust Racing]

Cheers

Edited October 27, 2015 by ActionDan

[Hadouken]

If you really want answers then it's time to read the hundreds of pages on these turbos.

But let's be honest. -9's or go down the gtx route.....

[No Crust Racing]

I'm good I think, I had my heart set on -9s, but saw these flowed -7s and they seemed cheap as they included apexi pods, hard pipes etc.

[Anfanee]

My R with -7's made 320kw...

E85 i'm still waiting on the build. Expecting around 350kw

[No Crust Racing]

Not bad, must have been maxed?

[gtr jet]

I'm the same as Anthony on E85 but you're right about trying to get E85 in Wodonga. I wouldn't bother unless it was a track car.

[No Crust Racing]

I've thought about it as a few of the boys get it semi regularly for their track cars (contemplated putting my silvia on it).

Given I'll be driving this monthly or fortnightly at most it could be doable with a 200L drum in the shed.

Easier for me to just stick with pump though. They even dropped the premium 100 at united I had the Silvia tuned on. Thankfully I can just dial a little timing out.

[Anfanee]

Not bad, must have been maxed?

oh yeah it was completely maxed.

[Roy]

If you really want answers then it's time to read the hundreds of pages on these turbos.

But let's be honest. -9's or go down the gtx route.....

Huh? -9s are bankable bolt on responsive 330rwkws....or not bolt on GTX headache turbos that require machined comp covers or custom pipping and 22psi + to really differentiate themselves from the GT series to get their best out of which on 98 will stll be capable of making +75rwkws more all on a std engine doesnt sound the logical alternate route to take....???

Dan if you only want 330rwks then just get teh -9s or the GT-SS, slap em on , tune em up and away you go . By the time you buy a set, get them machined, balanced with the cost of the new compressors etc....its end up way more expensive and at the end of the day you sound like you are only the boost you need to make 330rwks on a std engine on 98. As for reswponse and power...well the smaller -9s will spool quicker byt make less power...no beating basic physics when they are all the same family of turbo

[Hadouken]

Relax mate. I threw the gtx in there because he was from the start talking about -7/5 hybrid. Okie dokie.

We all know what -9's are capable of. It has been documented into the abyss and back.

[No Crust Racing]

How far can -9s go?

I assume the head gasket or bottom end is the limit?

[Hadouken]

A handful have claimed 380kw @25 psi.

I think 25psi would be the absolute max for them.

[GTRPSI]

I had some unknown HKS turbos on my GTR that the previous owner told me were 2540's (very wrong)

When we removed them the wheels were -5, the front housing was -7 and only the HKS cast dumps that came with them would fit, proper GTR dumps wouldn't bolt on.

I spent 2 nights straight trying to work out what they were by measuring up everything, eventually i gave up as it was not listed in any Garrett or HKS chart.

ID plates were also removed only the HKS casting was there on the front.

Eventually they ended up on a R33 GTR that safely made 380Kw at all 4 on E85 on a safe tune........apparently there was a lot left in them but the owner didnt want to push it as he had a stock bottom end.

Very responsive too after pon cams, cam gears and a good tune......

[No Crust Racing]

A handful have claimed 380kw @25 psi.

I think 25psi would be the absolute max for them.

On e85 though?

How much can the factory headgasket and bottom end take though?

Worth putting ARP headstuds at that point, even on a stock headgasket just to keep the head down.

[gtr jet]

If you only want 330 then just slap the turbo's on and away you go. Head studs and a new gasket will always be good insurance but aren't necessary at that power and boost level.

[No Crust Racing]

When are they required though... I'm not against more power if it's available safely