rutz964C4

Has anyone modified the cams? What is your experience? Is it worth? price, etc...


Once I heard that you can get the same performance as a 3.8L upgrade for less price, is it true does the car end with more torque?



ALEX

warmfuzzies

Highly unlikey to end up with a 3.8 comparrison, though it mught be possible it would probably be a peaky as hell...........
Cam regrinds are a cheap way of obtaing different lift and slightly different timing (open/closing) but me personally, I'd would opt for a known reputable way of upgrading the power, there's many a thread round here about power upgrades........

Kevin

Christer

Alex

There is a Rennlister called Gavin who rebuilt his engine with different cams and got a good power increase, but I don't know that they made all the difference on their own. I would suggest cams would be part of a larger project rather than installing them on their own without further work.

The comparison with a 3.8 conversion is fair. If you just installed 3.8 p&c's without doing any other work then the gains would be limited - but then no one would do that.....

warmfuzzies

Christer,

Gavin had a tad more than just a cam grind done:-
RS LWF & Clutch
De-cat
Cup pipe
Injector overhaul
Machine Heads (to raise compression ratio)
New Valve springs and Titanium retainers
Sport Cams
Cup Airbox
K & N filter
Re-chip
Plastic inlet manifold and large throttle body

As you can see from the list, he had sport cams fitted, not a cam grind (modifying the cams) which would give slightly different results, unless the cam is metal sprayed, then reground to a different profile. Plain regrinds normally, I say normally just grind back the heel of the cam, thereby giving extra lift. This is ok providing the cam followers/springs are up to the job, then you have to make sure that the spring pressure isn't excessive, otherwise premature cam wear will naturally occur.

I have some limited motorbike experience in this area.

Keep us advised though on your experiences, must be only 4 weeks to go now? God how do you manage for so long.......




Kevin.

Christer

Kevin

I read 'modifying the cams' as changing them, not grinding.

My main point was that you certainly would not just stick some new or modified cams in there without doing alot of other work with it (as Gavin has done). Apologies for my lack of clarification. The same also stands for the 3.8 conversion though. On its own its only an increase in volume of around 4% displacement (3600 to 3746cc) and wouldn't be a worthwhile conversion, but as I say no one would do that.....or cams on their own. Would they?

I believe my car went to the dyno for base figures last night, so yes I would think a good 4 weeks to go. And I can't stand it.

Gavin

Hello guys,

The cams I believe were worth about 8 - 10 bhp tops ( These were Genuine Porsche cams). They are good fun, in that they define the power range more clearly, ie you can really feel point at which the 'extra power' begins to build. But they do not adversely affect low speed torque. The idle is slightly rocky, but quite acceptable(this is made worse due the LWF.)

You could get more power from a more aggressive cam upgrade, but the trade off would be low speed torque issues and very ragged idle.

I think like alot of the gains are made from the combination of changes that are made to an engine and trying to ensure that they compliment each other.

If you work out the specific output per litre and just increase it accordingly to cater for the 3.8 conversion (based on 250bhp for 3.6 litres) you get about 260bhp or a 10 bhp gain. A pretty expensive mod for the power. However as Christer said, not many people would do this in isolation.

This is backed up by figures for a 3.8 engine to the same spec my 3.6 engine 304bhp vs 293bhp. The gains in torque are higher, about 15ft lbs

Looking forward to hearing how you get on Christer.

Hope this is of help.

warmfuzzies

Hi Christer,

Yep can see what you mean. I wouldn't install them in isolation either. Makes interesting reading though all the changes people are making, makes me what to go for it sometimes, then reality bites........ho hum.

Be good to see what your car does on the dyno, I should imagine some tremendous grunt from low down the revs........

Thanks also Gavin for chipping in, it's interesting to hear what the cams were worth in isolation.

Regards
Kevin

rutz964C4

Thanks for the responses

What I am looking in the car is for a consistent 290-300 HP specially looking in increase of low power more than peak power, my car actually has installed:

- Ruf Chip
- KN Filter
- Cup pipe

Not installed:
- EVO Cone Filter
- Bigger Throttle body (could not installed my car has the metal manifold and needs the plastic one)
- Custom Chip

I suppose that to get to that power there are many options ones may need to open the engine like a 3,8l conversion which is a bit expensive, hot wire film....


Any ideas which is the best way to go..





ALEX

ian c - u.k

do you want to buy plastic intake system ?
or do you want to sell the bigger throttle ?

i can help you with either !!!

Anatol

Gavin,
You have a PM regarding your camshafts.