09-04-2018, 08:09 PM
(09-04-2018, 04:07 PM)Chris71 Wrote: [quote pid='621352' dateline='1523280179']
Out of interest, how different is that engine to the GTI-6/Rallye unit, is there anything to be gained by simple bolt-on mods?
[/quote]
They're quite different Chris. The main ones are:
>Cylinder head (valve sizes not the same between the two)
>Cam (higher lift in GTi)
>Double valve springs in GTi
>Pistons (no dish = higher compression ratio in GTi)
>Inlet & exhaust manifolds
>Fuel injectors
>Engine Management
>The GTi revs to 7.5k. (The XSi revs to 6.5k max. There isn't in fact that much difference in torque between the two engines but the XSi develops it's torque at lower revs & starts to run out of puff at about 5.5k).
>6-speed gearbox
There aren't really any 'simple' bolt-on to gain power on the 16v XSi - the Bosch MP5.2 ECU fitted won't handle many changes beyond standard. Some say fitting the inlet & exhaust manifolds from the GTi make the car feel better but the exhaust manifold is a pig to fit with the engine still in place and I think you then have to use a GTi cat too.
The cheapest performance upgrade you can make to the XSi is probably to put it on a diet!