cam choice , stick with 266 or ph2 with the gt2056
Turbo Mini Forums

Men, considering fitting the gt2056 over winter .

The car drives , pulls well as it is , a tad laggy at 4k to boost but I don't mind too much.

Question is if I fit the gt20 should I stick with the 266 or put the phase 2 in ?

1293, forged omegas , 1.5 , 7.5:1 comp ratio

thoughts

Intercooler or not ? A good bump in compression would certainly help off boost too

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

What turbo are you running now ? Agree with Stevie, thats a super low compression ratio. How much boost are you planning to run ?

Phil.

WWW.TURBO-MINI.COM

Yes got a nice big intercooler.

Running 11psi at the moment at 138 bhp flywheel

Need to keep it reliable to thrash on track , i was thinking 16-17 psi , i no with the compression i could possible go more . Its ok off boost , and not so fussed about off boost power .

A rebuilt t3 phil .

Oh running mega jolt as well .

Im not after crazy power figures either. I could quite easyly up the boost as it is and leave it im just thinking it might make a bit more power and more efficient with the new turbo etc

Edited by cossierick on 22nd Oct, 2016.

If you're not after huge power, I'd up the compression, and run the GT20 at 1bar or so. You'll see a decent hike in power without going daft.

Phil.

WWW.TURBO-MINI.COM

Phil, whats my easyest way of upping it ?

Stick with the 266 then or swap it.

With such a low compression ratio, what about a cam with a wider Lobe Separation Angle such as the MD274 injection cam.

A wise man once said "shut the barn doors to prevent the horses bolting"

before we get too far are you sure on the 7.5:1?

if so I'm assuming, 18cc pistons, and 28cc in the head? or are the pistions runing down the bire a bit... if they are I would look at getting the block decked to get them up near the top, I generally build to 5 thou down, to give room for a skim if its ever needed.

thats assuing that as your talking about swapping cams the engines coming out anyway.

other options eould be to swap to 15cc pistions, or skim the head, although I would avoid that as it messes with the resale value, and the rocker geometry.

Email from med !

Dear Richard

engine was a 1293 turbo engine with 020 x 15cc dish pistons , 266 cam and steel flywheel assembly, fitted with our FIS head and 1.5 rockers comp ratio 7.5:1

Kind regards,

Steve Whitton

I dont want to get too involved with stripping the engine, im removing it from the car to alter the drop gears and swap for the gt20.
I need to replace the timing cover gasket as its leaking so wandered about cam swap !

Colin, im not bothered about a lumpy bottom end lol but i have a ph2 allready !

Edited by cossierick on 23rd Oct, 2016.

fair enough,

ok FIS head is apparent 28cc, so pistons must be circa 30 thou down the block,

phase 2 would be a better cam IMO, remember that you'll want to change the followers though... so if you dont want to split the tranny leave it as is.

with a CR that low I'm conrtadicting myself but I think I would look at a head skim, if you skimmed it down to 25cc that would be a good balance, that would get you to 8:1, and if you ever flushed the pistons 8.5:1.

another easy try is swapping the rockers, pop a set of standards on there and see how it feels,

the other alternative is stuff a load of boost up it to make use of the low CR, with the GT20 it should take 25psi no probs, (RR setup dependant obviously) so say 20 psi, and look at some boost regulation to bring the boost in progressively through the rev range?

So to be fair its going to be swap the turbo and just up the boost .

cant argue with that,

to be fair it really a track car ro not to much point getting over woried about low down boost ect, also theres the change ione thing at a time aspect :)

Thanks joe

My only thought was say I run 20psi now as I am , if I upped the comp and only ran a bar I would probably see the same power , the lower end drivability isn't an issue, but !!!!!
less boost on a slightly higher compression should be a safer option should it rather than running loads of boost ?

to be honest, I think it would be safer running the lower CR, at 7.5 you'll be hard pushed to run into det problems even at 30 psi.

Thanks joe