cams turbo. - Saxperience

adzvtr · 15th September 2009, 22:12

canu run catcam 708s
when turboed
16v vts,

Ryan^p · 15th September 2009, 22:15

it can be done, is it the best idea for your set up.

Probably not in most cases.

adzvtr · 15th September 2009, 22:18

its for a m8, he is looking at the cituning set up,
i got 708s in mine but i going itbs,
he wants the same cams, but i nt sure if they will work

Ryan^p · 15th September 2009, 22:23

why does he want the same cams?

does he know that in most cases you dont want wild cams with boost?

adzvtr · 15th September 2009, 22:31

he hasnt a clue, hence why im asking lol
i not that clued up on turbo setups myself
why isit not gd to run wild cams

Ste · 15th September 2009, 22:46

You'll get blow through with them at high rpm so ive been told, with the normal timing. Catcam do a set specific for turbo engines.

adzvtr · 15th September 2009, 22:51

normal timing as in standard timing, or cam specific timing

Ste · 15th September 2009, 22:55

Quote:

Originally Posted by adzvtr

normal timing as in standard timing, or cam specific timing

At the cams specified timing, you could retard them but then its just pointless fitting them.

The turbo cams make the AFR easy to dial in/keep safe too. Standard or Turbo cams would be the only choice.

Andy_K · 15th September 2009, 22:58

708 should work ok as long as he isn't running mega boost. Seen several 'low boost' conversions running piper 285 cams which are similar profile to 708's.

For higher boost the Cat cam turbo spec cams are the best bet though as the duration is staggered to prevent blow through

adzvtr · 15th September 2009, 22:58

cool, think he only planning on keeping it about 6 psi, if he wants more later will need internals and bits anyways,

Ste · 15th September 2009, 23:03

With 6-7psi go with standard, sell the 708s and put towards dropping the compression.

Andy_K · 15th September 2009, 23:04

If he's thinking of upgrading later, might as well just get the right cams 1st time round. Be cheaper in the long run. Just get the turbo cams straight off and dont bother with 708's etc as you will lose money when you come to sell them.

Or do as Ste says above

adzvtr · 15th September 2009, 23:09

on a whim, what if he uprated the springs lifters followers ect. to compensate for blow through

Andy_K · 15th September 2009, 23:13

dont think that would make any difference tbh, as its the cam that is also starting to open the valves, rather than just the boost pushing them open. Its the duration of the cam that is the problem, not just the boost pressure (that my understanding of it anyway). The turbo cams have a shorter duration on the exhaust side to prevent this

Andy_K · 15th September 2009, 23:14

Also uprated valve springs can cost a fair few ££'s, again adding cost

Ste · 15th September 2009, 23:20

For the £500 it would cost for the springs and lifters you could have bought a set of low comp wossners with the standard cams and knock the boost upto 14psi. And for the £300 saved from not buying the turbo cams you could get a high quality intercooler and oil cooler.

If its not being done on a budget then id avoid the N/A spec cams, the turbo lag would be emphasized, the AFR would be harder to keep safe, the revs will need to be high to keep it on boost and you don't want that with a turbo setup you want to keep the power under 7k so you don't wear everything out in a week.

You want the turbo to spool upto full boost low down in the RPMS and because the N/A cams steal low down torque to put up at the top of the range then you lengthen the time it takes to spool the turbo.

adzvtr · 15th September 2009, 23:21

ye, will all cost money in the end, just getting ideas for him so can run all options by him, and if i know him he will want to try lol

adzvtr · 15th September 2009, 23:23

but i think i am starting to understand now.
big cams good for n/a as ur trying to allow more air in.
not so gd for forced as thats pushing more air in.

Ste · 15th September 2009, 23:24

The money is best spent on a high quality turbo thats spec'd right on the money for the power he wants. And then on dropping the compression so you can get above the 200bhp mark and then on the cooling water/oil and boost so you can enjoy it for a long time.

Andy_K · 15th September 2009, 23:26

Quote:

Originally Posted by Ste

For the £500 it would cost for the springs and lifters you could have bought a set of low comp wossners with the standard cams and knock the boost upto 14psi. And for the £300 saved from not buying the turbo cams you could get a high quality intercooler and oil cooler.

If its not being done on a budget then id avoid the N/A spec cams, the turbo lag would be emphasized, the AFR would be harder to keep safe, the revs will need to be high to keep it on boost and you don't want that with a turbo setup you want to keep the power under 7k so you don't wear everything out in a week.

You want the turbo to spool upto full boost low down in the RPMS and because the N/A cams steal low down torque to put up at the top of the range then you lengthen the time it takes to spool the turbo.

completely agree with this tbh

Basically, there's little point in throwing loads of money at lairy cams, as if peak power increase is the ultimate goal, there are much higher gains to be had by running higher boost than can ever be got with any cams. Just that otehr things will need uprating to cope with the higher boost levels (oil cooler, intercooler low comp pistons etc).