402TT

I´m running 2 pc PT5830 on me 402 cid. So far I manage to run 9,75@148mph 1,6 60” on 3650 lb car ( full street trim pump gas with dual 70 meth and DR tire). This is at 15-16 psi. I have 15psi at 3500 RPM. This is internal westgate. I have issue building psi a bow spring at +5000 rpm but if I start from 3-4000 rpm I get more psi and more power. So what I have been thinking about is ether changing the turbo setup to new external westgate setup using either PT6262 or 6265. Or change me psi control system to AMS1000 or MSD with CO2 to fight me spring pressure. Question is will I lose me quick spool and get lag with 6262,6265? And or will I be able to control internal westgate with CO2 system?

Thanks.

boostin01

why not convert ur current turbo rear housings to external gated setups and give that a go?

402TT

I have is T25 APS manifold so I can not do that.

Professor_speed

iTrader: (8)

Ok first off internal waste gates get a bad rap some times. Does your current waste gate actuators have one port or two? If it is single port then installing a better boost controller will not allow you to build more boost. I would switch to two port actuator before buying new turbos. They will allow your positive manifold pressure help your wastegate actuator stay closed when needed and thus build boost faster. It sounds like exhaust back pressure is pushing the gate open early.

402TT

I have single port. So you think with dual port activator I will be able to reach 20 psi which is as far as want to go?

Professor_speed

iTrader: (8)

For the money I would give it a shot. An external waste gate will have two ports (one port uses boost to hold the gate closed the other pushes it open like normal) that's part of the reason they control boost better.(larger size and better priority are the others) the question is weather you compressors are maxed out or if the wastegate is being pushed open. To me it sounds like your gate is getting pushed open early due to back pressure.

If that is the case I would try a dual port wastegate actuator before I changed turbos and went through the trouble of adding external gates. Changing the actuators is cheap and easy. Will your 58mm internal turbos make the power of 62mm external turbos? NO, but they might hit your goals and with alot less head ache.

Is your car able to hold your 15-16 psi to redline? if so the compressors probably are not maxed. If boost is dropping then more turbo is probably the only fix.

402TT

Thos turbo are max 600 hp each so I should still have 2-300 hp left in the system. According to HP tuner logs I have peak INJ Duty at 5400-5500 rpm and it is about the same to 6500 rpm which is as high as I go. I hold psi up to 6500 rpm.

Professor_speed

iTrader: (8)

Well sounds like a perfect scenario for dual port actuators, It will cost lest than $100 so why not. Makes sure you report back on how it works out.

402TT

I will change to dual port activators to start with and I will port back in the spring after testing.

Thanks.

402TT

Ok finally I can report some result. I have changed to dual port activator and 4 port relay instead of 3 port. First I did mod 3 psi spring but that did not work at all do to it could not hold on higher psi ( 14-15) and with 3 psi spring I had 6 psi at 3500 rpm and then psi did build up with rpm and at + 5300 rpm I had 15 psi ( internal west gate hole to small). Then I did go back to the 9 psi spring and with that spring I can easily reach 20psi. So it seems like this will work fine for me.

Professor_speed

iTrader: (8)

Great to Hear I was wondering if you would report back, Also let us know when you get back to the track