donny

I am currently running 850's in both primary and secondary's, is this enough fuel to support a TO4s or GT35/40? Or, should I upgade my secondary's?

Thanks, Don

Also, whats the difference between the GT35/40 and the GT40R everyone keeps talking about?

Sponge Bob Square Pants

At how much boost? Streetported?
They will be enough if you are running very very low boost.

donny

the engine is street ported/3mm seals (2k on new motor) Would like to see 400rwhp.

manatecu

iTrader: (6)

I needed 1600's and 850's for my T04s - so no 4 850's wont work - get a secondary rail and 1600's.

BoostedRex

Then no, I would recommend 850cc primaries and 1600cc secondaries. That way you can SAFELY make that power. Injector duty cycle is something to keep in mind. You probably could get away with the 4X850cc setup, but if you could it would be maxing out the injector cycle. It's just safer and will save you money later on to do the bigger injectors now. I've never met anyone who didn't want more power after a little while. It's just human nature. If you do the big injectors up front then you can bump up the boost when you decide that 400rwhp isn't enough. Just my .02.

Zach

donny

Thanks guys.

Whats the difference between the 35/40 kit and the long awaited 40r kit from A-Spec?

BoostedRex

The 40R has a T04 hotside and a bigger compressor as well. It's capable of much more HP than the 35/40. Any info you might want to know about it you can get from ZeroR here on the forum. He is the owner of A-Spec Tuning. That's the company that is doing all of the 40R kits. Sean is a great guy and has TONS of knowledge.

Zach

CYM TKT

iTrader: (4)

yeah im on stock twins with 4x 850 and at 15 psi they are already at 85% duty cycle with a 3mm streetport

BoostedRex

Case in point right there. Thanx CYM TKT. I was hoping to get some solid numbers to back up what I said. Laterz.

Zach

Jesuscookies

iTrader: (1)

Yes you can.

I am currently running a single turbo and 4 850's all around. This set up is good for 400RWHP. Check out max coopers web site. He has a fuel calculater that will help with you decision.

GoodfellaFD3S

iTrader: (213)

Maybe at 100% duty cycle it is. To safely make that power long term, I would upgrade your secondaries (and your fuel pump if you havent already).

I have been running 400rwhp at 17 psi on the streets (when she runs, lol) with 850s/1300s and a Nippondenso pump. Also, keep in mind that if you go the upgraded sec rail route you will also need an aftermarket fuel pressure regulator and a handful of AN fittings and fuel line.

donny

I have a Nippendenso upgraded pump.

rynberg

I don't see why 550/1300cc wouldn't work. That would allow you to maintain the stock secondary fuel rail (and regulator, etc). If you are still running too high of duty cycles at your desired power level, THEN upgrade to 850s in the primaries.

twokrx7

iTrader: (1)

Much depends on how you tune the car. If you run a 10.5 AFR vs 11.5 AFR that a 10% difference in inj duty cycle. Throw WI or the new butt plugs (lol) on the car and tune it to 12 AFR and save some fuel.

Probably need a solid fuel pump and power supply to keep the pressure up as well. Sometimes drop-in pumps cannot keep up without some electrical power supply mods.