Sigma-galant.com

Hi guys
Im new to the forum and i own 2x Sigma turbos one is a peter werrett special with a vr4 engine
it was featured in issue 141 of hot 4s and the other is number 81 of 500 a genuine sigma turbo.
I have a slight problem with this car i recently put a 2.6l engine in with the combustion filled up with
weld on the heads to give it higher compression. originally this motor was not intended for a turbo but
i put it in regardless. now the car goes well but when under boost its starts to breakdown and ping.
Anyone no what i should do? Would a larger cam fix this problem? Also i need a heavy duty clutch to suit this car
anyone with info would be greatly appreciated.
Cheers
Steven

hey mate welcome to the site. nice pair of siggys u have. i would suggest getting another cylinder head for a astron 1 engine, or running water/meth injection and turning the boost down. pics?

and put up some pics. . . . lots of pics

welcome to the site

Agreed - pics would be great!

Are you using a turbo Dizzy? I know there has been a few topics regarding the vaccum advance canister and how that is diiferent to the non-turbo ones. Maybe one of the Turbo gurus on the site can confirm whether this will cause your symptons.......

sounds like your comp is to high and its detonating bad
the only way to fix this is go down with the comp ratio or stick in heaps
of water/meth ,but that a temp solution
drop the comp ratio and it will be all good
cheers stealth

the setup in the car is stock except for the 2.6l. When the motor was rebuilt it had flat top pistons put in it which of course
gives it more compression. What is the best head to use? Can you get the big port head to fit the inlet manifold of a turbo sigma? I want to try and keep the car as close to original as possible so i want to stay clear of fuel injection. look forward to
your advice. Thanks for the comments will post pics soon.
Cheers
Steven