Exhaust cam mod..

[VEEDUBBED 0]

Right,last saterday i installed a spare 1.8 exhaust cam and modified it to work as an inlet,all went ok,i pressed off the cog timing wheel and aligned the cams up in a spare head,welded the sproket back with the famous 6 degree difference,rock steady idle and very good top end,a bit more compared to the KR inlet cam used previosly.

The problem is that i've lost pressure from the supercharger,before it went to 0.8 using a 68mm pulley,now it's down to 0.4bar,the charger's is in exellent condition there are no boost leaks that i can hear,it only happend since swapping the cam,i wonder if the cam has too much overlap for a charged 16v engine?.

Even with only 0.4bar absolute pressure i still spanked an Audi TT effortlessly,just to make certain i red lined the engine in 4th,pressure still 0.4bar,speedo indicating 219km/h,flat out.

Anyone got a similer engine to mine who may have had the same issues?.

[flusted 0]

Stealth used to use the 2 exhaust cam trick on there 16v turbos so it should be ok?

[jezzaG60 0]

Is the car performing better now?

 

It could just be that the engine is now breathing a lot better with the exhaust cam.

The cam has a fair bit more lift so i would expect to see a drop in boost pressure in the inlet manifold. At the end of the day.... the boost in the manifold is a measure of the air thats NOT getting into the engine, if you can make your engine flow more air with a ported head or a cam then you will be getting a better cylinder fill and more power!

 

When i fitted a cam to an 8v '60 boost dropped by 3psi but we gained about 18bhp.

 

Now go stick a 65 on it and let all hell break loose :D

[VEEDUBBED 0]

I fitted a 59mm pulley this morning,re-tuned the co-pot to 390 ohms,bigger injetors etc so maybe tonight i'll try and get the car flat out in 5th and see the difference in preformance,must be carefull though,last week i nearly hit a stray cat at 130mph...