Performance Camshafts

[timucin]

i know some of you are using hi degree/lift aftermarket camshafts.here are some questions for you

-what degree/lift do you use for fast road use?
-what brand?
-where to get?www?
-is only camshaft enough does audi valve spring tolerate hi lifts?up to?
-is there any company have these parts as kit like cam-lifters-springs-locls ?
-gains?hp?torque?
-rpm range?
-disadvantages ? comsumption?idling?
-prices
-is it hard to install?


thnx for your help

[dan_b]

Another question to add to the mix

If you install different cams, do you then need an ECU re-map as well?

[Stick Insect]

If you make any change to the operation of an engine you will need to make changes to the operation. With carburettors you needed to change the settings of the engine when you were high up in the mountains.

Changing the camshafts will make a big difference to the engine. I can't guide Timucin but I have heard that the exhaust camshaft from the 7A engine ( 5 cylinder 20V non turbo ) is a good one to go for.

Pisobiker, Paul, Minhea or the others will be the best people to help.

David

[Mihnea]

As I already told Timucin, bigger cams are only necessary after 450+ HP on an RS2, so the upgrade is pointless. On stock S2s, the exhaust cam off an RS2 brings a bit more HP at the top end but that's all.

HTH,


Mihnea

[timucin]

Mihnea;
yep i remember you told me about camshafts but if we add camshafts to a 420 hp car wouldnt it be 440-450?

just curious

thnx

[Pisobiker]

Timucin, supposing changing to higher lift-timing cams could provide +20-30 hp on a 420 hp layout, you cannot avoid taking into account the other factors:

there is a close relation between cam lift-timing and volumetric efficiency. This affects almost proportionally output, but also automatically changes turbocharger working point.
If you increase VE and leave boost the same ECU and boost gauge will "see" same boost as before but you have filled the cylinders with a greater amount of charge thus forcing the turbo to flow more air (increasing the output). If this is among small differences your fuelling and your turbocharger won't be affected (but performance increase as well), otherwise mechanical and electronical upgrade is required.

Try to imagine you're at 420 Hp with your setup, and cold side of your turbocharger is working at about max flow capabilityes (choke line): if you increase 5% VE you will need (at same manifold boost) about the same increase on flow, which cold side is not able to provide. If you don't lower boost or change to bigger cold side you will induce the turbocharger to overspin. Then, supposing the turbocharger will be able to provide enaugh flow increase, since at WOT ECU controles mixtures by it's internal map, you'll need to enrich fuelling not to run lean.

If you go to a higher lift-timing camshaft and a freer intake + exhaust on a stock turbocharged engine, you could gain even 10-15% hp without any other modification, because turbocharger is working safely under it's max capabilityes and fueling is probably in the "rich side". But playing with tuned engines, where working parameters are already setted close to the limit, attention must be put over all of the aspects.


Marco