20vt upgraded cam questions

[andy_dea]

was looking through a performance vw the other day and see that more companys are starting to produce diff cams for the 20vt engine,

anyone with a big turbo upgraded theres?

just dont seam to hear much about cams on these engines

 

[bigjode]

When I had a NA car, cams were one of the few ways to increase power considerably, aside from adding a turbo. The downside of them was that they made the idle lumpy, and made lower rev range driving difficult (eg around a busy town centre, in traffic etc.)

The reason I wouldn't do it to a turbo engine is that there are many ways to get big power increases that won't have such a negative effect on normal driving. Maybe thats why so few people do it.

 

[andy_dea]

i just curious as all the forge internals have valve cut outs for hi lift cams

also stock cams in my car are prob to make peak power at about 5.5k-6k

so with bigger turbo the top end power is well over 5.5k and by this time the valves are prob not fully open, and not taking full potental of the power been produced

just thinking out loud really but be good to have some info on it

as m next step will be engine rebuild all internals, hopefully large port head if can find one, and be doing the valves, so would make sence if cams going to help fit them at that stage

idle is more down to mapping, injector size and spray ect, which can be kept sensible if mapped correctly on the turbo engines

 

[bigjode]

idle is more down to mapping, injector size and spray ect, which can be kept sensible if mapped correctly on the turbo engines

If thats the case then I don't see a problem with them. I just remember when I looked into it on my Focus, the consensus was that town driving turns pretty shitty.

 

[Saul]

you're both right to a point.

when talking about idle, the ECU requests certain parameters from the engine to be met to keep as good an idle as possible, however the cams physically limit these parameters depending on the angle they are cut at as this is what sets the level of valve opening.

i think the reason cams arent changed on the 20vt is that so much more power is released with bigger turbos/heads/downpipes

 

[t18con]

ive a set of cat cam ones sitting, £605 all in. these are to suit standard valve/follower setup, think the mechanical setup adds £800 to the price for the solid follower and shim, but rev limit is 10k ! mine are similar to this setup only the cheaper range.

http://www.seatcupra.net/forums/showthread.php?t=74808

 

[ryan_s3]

I think above 400bhp or the turbo that requires 400+ cams are a good idea anything less,standard ones are fine.