What Cams For A Gti6 Turbo?

[Rob Turbo 3]

As title really, can I stick with the standard gti6 cams, possibly put the timing out on them by a tooth (or adjust the timing if they have adjustable pulleys), or would I be better off with something like 306 xsi cams, just like the 8v xsi cam is good for the 8v turbo engine.

 

I'm not shelling out for regrinds or anything, I can't afford to go that far!

[taylorspug 7]

XU7 exhaust cam with the GTI6 inlet will give you less overlap im told, so yes your thinking would appear to be along the right lines.

[Tom Fenton 1,562]

Seeing as your GTI6 head comes with two free cams in it I'd try these first, the way to go from standard is to open up the LCA which will decrease overlap, you will have to trial and error though as too far and you'll find it won't start for love nor money.

[Rob Turbo 3]

What do you mean by increase the LCA?

 

Thanks,

Rob

[Tom Fenton 1,562]

LCA is the lobe centre angle, the angle between the peak lift on the inlet and exhaust cam lobes. On a single cam engine e.g. an 8v this is fixed, however on a 16v engine with twin cams you have the advantage of being able to adjust this by altering the cam timing. If you open up the LCA you will naturally reduce the overlap, overlap is good for high revving NA engines but not so good for turbo engines, unless you want something that doesn't come onto boost until 4000rpm and will rev to 9000rpm.

Edited April 1, 2009 by Tom Fenton

[Rob Turbo 3]

Ah right, more or less what I was thinking but with technical terms, although I wasn't sure how it would effect the running of the engine.

 

Thanks,

Rob

[rapidcossie 0]

Cam choice depends on alot of things.

What size turbo you using?

 

what power you looking for and where about do you want theis power in the rev range?

[Rob Turbo 3]

I'll probably be using the t25 off the 8v engine, but with a standard t25 exhaust housing on it, because it's hardly done any miles since the rebuild and upgrade (60-1 compressor wheel and A/R 80 compressor housing), I'm after around 250 - 300 bhp

[petert 614]

The GTi6 cams are already very mild. I wouldn't down grade to anything else, you'd just be throwing away lift. Just advance the exhaust cam a tad (decrease the lift @ TDC, or increase LCA). A tooth is way too far. I'm suggesting just 4-6 degrees crank.

[Sam 4]

Yep I was going to use GTi6 cams on my build