Scrapyard Tuning For A 306xsi?

[macaroni 17 1 Cars]

Assuming I get my free 306xsi through it's MOT, I was wondering if any intake bits from an S16 or GTI-6 would fit to give a power increase?

 

For example, is the throttle body any bigger?

 

Any help gratefully received.

 

Cheers,

 

Antony

[smighall 1]

Is it an 8v or 16v XSI?

 

16v i believe the exhaust and inlet manifolds can be used from a GTI6

 

8v i think you can get good gains by using 8v 205 manifolds.

[macaroni 17 1 Cars]

Tnanks for the reply, it is an 8v. Is the exhaust manifold different for the 205 gti?

[Richie-Van-GTi 71 2 Cars]

same exhasut mani, swap all the intake over off a 205

[huckleberry 0]

The entire engine from a S16 or GTI6 would probably fit

[smighall 1]

doesn't the 205gti cam works well in the 306 lump too?

[macaroni 17 1 Cars]

Ha, yes thanks for that huckleberry. That wasn't quite what I was thinking of.

 

Cool, so what is different/better about the 205 intake system?

[Richie-Van-GTi 71 2 Cars]

just flows a lot better, could always copy me and stick a 205 head on complete with cam, means increase in CR and better cam

[Anthony 1,003]

just flows a lot better, could always copy me and stick a 205 head on complete with cam, means increase in CR and better cam

Seems like a bit of a retrograde step swapping to a worse flowing head with smaller valves...

[Richie-Van-GTi 71 2 Cars]

valves are same size and my thinking is flow is provbably around the same as a 2.0 head with a 205 inlet on as you either got problems with port shape or change florate to same as 205 when you reshape the ports.

[Anthony 1,003]

valves are same size and my thinking is flow is provbably around the same as a 2.0 head with a 205 inlet on as you either got problems with port shape or change florate to same as 205 when you reshape the ports.

I've got the flow graphs for a standard XU9, standard XU10, and QEP fettled XU10 that's had the ports reshaped and blended in. The XU10 head flows *alot* more, which is partly why there was the phase of people doing XU10 head conversions onto XU5/XU9 bottom ends. I'm sure I've posted the graph in the past...

 

The inlet valves are 1mm bigger on the XU10J2 head compared to the XU5/XU9JA

[Anthony 1,003]

Indeed I did post the flow graphs for the XU9 vs XU10 vs QEP fettled XU10 heads here

[Richie-Van-GTi 71 2 Cars]

Thanks, makes for some veryinteresting reading, shame the questions about the route Ive opted for have been answered as thorughly. TBH I think for what I have available to me Im going the best route as the increased CR, gti cam and bike carbs should see me a nice healthy gain. I do have the 2.0 head but for that to work properly would mean different cam as the gti cam seems to be slack inside one of the end caps on the 2.0 head and it would also mean standard CR and reshaping of ports, plus it has a restrictive exhaust port.

[macaroni 17 1 Cars]

Some fantastic info there. That will serve me right for spending too long in the TU forum, I missed all that.

 

So, on a XU10 engine, the XU10 head is best (preferably with worked exhaust ports and XU9 spray bar), maybe with a 205gti cam and induction system?

 

The worked head is beyond my current means, but I'm very interested in the induction set up.

 

Just gotta get it through the MOT first...

[macaroni 17 1 Cars]

Would a backbox from a GTI-6 fit a phase 1 xsi?