Thread: Suitability of this turbo?

Depends on how Mich boost you want to run, without getting too far into it I'd say it'll run out of puff at arouse nd 15 psi at around 3000rpm on the Suzie.

No missing the waste gate won't hurt you on that engine with that turbo.sizing you'll need to adjust the pump to suit tho.

Originally Posted by Blknight.aus

Depends on how Mich boost you want to run, without getting too far into it I'd say it'll run out of puff at arouse nd 15 psi at around 3000rpm on the Suzie.

No missing the waste gate won't hurt you on that engine with that turbo.sizing you'll need to adjust the pump to suit tho.

By 'adjust the pump to suit', do you mean wind out the fuel screw?

15 psi at 3000 rpm would do me - no plans to intercool. I'm trying to keep things simple and the lack of wastegate appeals on these lines. Dump pipe would be an easy job to match up to the triangular flange also.

Seems to have the same turbine a/r (0.49) as the 19T but a smaller compressor and possibly one less blade on the compresser also, if that makes a diference. So without doing the calculations (because I cant), would I be right in guessing it would spool up a bit earlier than the 19T, but make less overall boost, becoming restrictive over around 3000 rpm?

Is it going to be better than one of the factory turbos, as the consensus seems to be that they're not that great?

The price on these is roughly comparable to a second hand T25 + a DIY rebuild kit - so looks like good value.

You want a wastegate. Without it'll turn into an exhaust brake by supplying too much boost.

Originally Posted by Dougal

You want a wastegate. Without it'll turn into an exhaust brake by supplying too much boost.

So help me understand this. How is wiring a wastegate shut different from not having a wastegate?

Originally Posted by mark2

So help me understand this. How is wiring a wastegate shut different from not having a wastegate?

It's not. Both are silly.

Without a functioning wastegate you need a much bigger exhaust housing and performance starts to bring the suck.

Originally Posted by Dougal

It's not. Both are silly.

Without a functioning wastegate you need a much bigger exhaust housing and performance starts to bring the suck.

I still dont get it. I thought there were quite a few on here who had wired their wastegates shut, to allow the turbo to develop the boost it is capable of. If this turbo for example can only make say 15 psi with a n/a pump, why is a wastegate necessary? Does a wastegate do more than just keep boost pressure within safe limits?

I know I'm probably overlooking some obvious fundamental of turbo theory.....

the wastegate allows more exhaust flow and lower exhaust pressure once enough boost has been developed. Letting the engine rev more readily and produce more power.

With a shut wastegate unless you have the fuel to match the boost keeps climbing, the exhaust pressure keeps climbing and power is lost to pumping loss.

With no intercooler my egt is the same at 20 and 24psi boost. But with the wastegate shut for 24psi the engine hits a power wall around 2500rpm.

run with whats dougals saying for the application your looking at setting up, it will be better than a NA 4bd1 at the bottom half but will hit a wall Im gussing around 3K RPM@~15psi.

having had a slightly better look at the numbers (and it wasnt that good) I dont think that exhaust back pressure is whats going to kill you in your intended application I suspect it will be compressor slip first and then you'll choke up on the the turbine..

very very vaguely

if you're going to run without a wastegate you want to run some higher pressure and flow rates on the compressor side (really really simply you want a bigger/better compressor wheel than the turbine) you also want a very fast free flowing exhaust with a larger apature on the turbine housing exhaust.

A wastegateless system should never be permitted to hit compressor slip as once that occurs the turbo can "run-away" as theres less load on the compressor wheel once it starts to slip. what follows after that is s quick death of the bearings/shaft and in extreme repeated cases shearing off of either the wheel as a whole or blades