Screechy turbo after 5SPI? No shaft play by hand.

[TERRA Operative]

It's got a T2860RS on it now, and it runs a bit better. It needs a tune etc before we really push it. It did make a bit of a strange noise close to 10PSI, so we are just going to throw it at a workshop.

I made lots of assumptions, probably incorrect as I am more experienced with superchargers, and know practically nothing about sizing turbos.

[the_random_hero]

Heh, better work than a certain 'performance' shop who wanted my old work to build him a manifold to put a GT35 onto a 2.8L diesel Hilux...

Will the turbo boost -over- 5psi? If it's leaking somewhere, I would expect it to be visible mapping out rpm vs. boost.

[TERRA Operative]

Yeah, it reaches about 10PSI before the noise starts. Everything is fine until then, might have to make some end caps and pressure test the system.

[JP]

the noise isn't coming from the booster?

[TERRA Operative]

That's one Idea I thought of too, although the booster is attached to a vac pump on the back of the alternator that discharges into the crankcase, so no direct connection to boost.
I mentioned it to my mate so we plan to disconnect it for a test this weekend (as well as map boost to RPM as mentioned above)

[TERRA Operative]

Ok, the problem has been fixed today.

The cause? Ebay manifolds.....

It turned out the flange was warped as usual for ebay manifolds (I told my mate to get it machined, but it didn't happen first time round) and a few of the bolt holes were too big, so they overlapped the ports on the head.
My mate took the manifold to Craig at Extreme Custom and got the holes welded almost closed and the flange machined. A bit of time with the die grinder to make the holes fit perfectly on the studs and we are now at 15PSI with no strange noises (just the nice turbo diesel whistle )

Next step is to wind it up a bit to 20PSI, get the fuel adjusted then stick it on the dyno to see how far we've come.

[mattysshop]

you would not beleive how many manifolds he has to surface or face..

all these young kids come in with 'oh nah it's not an ebay one... it s Gktech manifold...everyone usess them' put a straight edge on it... yep needs to be surfaced...

good to see your mate got it sorted! hopefully the desiel cracks into triple figures jokes...

[TERRA Operative]

Yea, it's pretty much par fpr the course for ebay manifolds. Means they are still cheap, but not as cheap as they seem.
Future plans are to get Craig to build a properly port matched manifold, but that's later once the body work and other stuff is sorted.

We've got triple figures in torque, but power is another matter. Might try screwing the boost up to 40PSI and see what happens.

[mattysshop]

yeh i saw the port matching... anything would be an improvement on that!