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Discussion Starter · #1 ·
Not put my car on a dyno yet but it feels so much stronger at high engine speeds, 4th gear at 6K rpm and its still going strong. Before the power would have died off now it just goes and goes! :D

Rough spec:

Phase II
Reds (my boost problems were down to the plugs not the injectors)
Porting (similar to what’s described on John’s site :beer: )
Vernier’s with:

XE inlet cam retarded by 7 degrees
LET exhaust cam advanced 2 degrees

Played around with this a little and this feels like the best set up for me, have to see what happens when I get it on the rollers though.

Matt
 

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i remeber when i put one in mine it felt a bit stronger, not sure if it was more me thinking it was pulling harder, ie a cam for a tenner giving lots of bhp just doesnt soun right, but sure felt like it.

why you adjusted em to those degrees btw?
 

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0ddball said:
are you the one thats running 4.5 bar pressure AND bosch reds ?
No that was me. I'm not running EDS phase 3.5 either now. Should be running the VMax Evo 6 some time soo - I hope :(

When I did the XE inlet cam mod I deffinitely thought it pulled better at high revs - I only got 1bhp more on the rollers though where as the Courtenay high torque cams gave a lot more torque and more bhp.
 

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Discussion Starter · #5 ·
Read the stuff on John's site, asked a few questions on here & CC. Tried a few settings (retarding the inlet on its own and again with the exhaust advanced). I'm not an expert on this but this is what I think is going on:

XE cam gives more lift and duration (better filling of the cylinder).
Retarding the inlet and advancing the exhaust reduces the overlap and any reversion this causes due to the back pressure from the turbo.
Also the dynamic compression ratio is reduced as the inlet is left open slightly longer during the compression stroke, possibly allowing the ECU to run more advance?

Have a look here for more in depth info:

http://homepage.ntlworld.com/johnnya/max-boost/cylhead/cams.htm
 

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I also used the XE inlet cam and for now it is running on spot on marks.
The car is quite laggy below 3500 but goes mental just above 4000, the power is strong to the limiter so I'm quite happy with it, except its not really ideal power delivery.

John A- you told me to retard the inlet cam by 10 degrees max, what improvements would I see from adjusting the cam timing?
Should the exhaust cam timing also be adjusted or should it be left alone?
 

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jonlem said:
...John A- you told me to retard the inlet cam by 10 degrees max, what improvements would I see from adjusting the cam timing?
it will run better overall, with stronger midrange and much stronger top end. Idle will be better, too.
Should the exhaust cam timing also be adjusted or should it be left alone?
You could advance it a couple of degrees if you already have the verniers in place - but it's not that important:beer:
 

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a vernier pulley has a central piece which attaches to the camshaft and a seperate outer pulley, the relation of these two can be altered by a few degrees to allow the camshaft to be advanced or retarded.

Word vernier is a method of accurately measuring using two slightly different scales. ie: vernier caliper.
 

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so is the amount of degrees between each tooth on standard pulleys too much to be playing with the timing ?? (valve clearance for piston i suppose)
last thing you want is valve touching piston! I've heard of skipping a tooth, but doing it on puropse!!
 
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