turbo and NA cams

[ah789454]

whats the difference between turbo and NA cams??

[wynode]

whats the difference between turbo and NA cams??Duration mainly

[TODA AU]

Nothing physically...
Where you set them can differ from time to time...
Regarding turbos...
If you've got a serious set up...
Big cams work great...
If you've got a wee wee playing set up...
The thing will fall on its nose...

Both long & short duration cams work in both normally aspirated applications & turbocharged applications..
The combination is what counts with regard to the end result..
Get it right & it's all good...
The reverse also applies...

[wynode]

So short duration cams don't suit a turbo setup over longer duration cams?

[Weq]

Ive always heard N/A specific cams hinder turbo performance moreso then a stock cam.

[Kit]

as wynode said, its all about duration.

high performance NA cams have a larger overlap (that is the time when both exhaust and intake valves are open) so that at ridiculously high rpm :) the exhaust gases exiting the cylinder aid in the intake of the unburnt mixture. If there was no overlap, at high rpm, the valves are opened and shut so fast that its not really long enough for enough unburnt mixture to enter the cylinder.

as the fuel mixture of a turbo car is being forced in at a pressure greater than atmospheric (1 bar). Long overlap is bad as it can mean the unburnt mixture can shoot straight out the other end through the exhaust valve.

hope that makes a bit of sense

Weq, btw, did you buy your civic turbo'd or did you do it yourself?

Chris

[bigpitty1]

With some after market NA cams there is a point where the intake and exhaust are open at the same time so the cylinders will will up completely.
You don't want this with a turbo because you won't fill the cylinders up with boost, boost will just run back out the exhaust.
There is also the timing and the duration

[Kit]

With some after market NA cams there is a point where the intake and exhaust are open at the same time so the cylinders will will up completely.
You don't want this with a turbo because you won't fill the cylinders up with boost, boost will just run back out the exhaust.
There is also the timing and the duration

ummm, bigpitty... what are you trying to say there?
:?:

[Kit]

Ive always heard N/A specific cams hinder turbo performance moreso then a stock cam.

Hey Weq,
Its not just the CAMs but the engine in general.

In a really brief nutshell:

The things that makes a high performance NA engine, directly contrast those things that make a high performance turbo engine.

a very broad statement is Power = Torque x Revs.
so *IF* all things remained equal, the higher you rev an NA engine the more power you make (in reality this isnt the case of course).

so, high revving NA engines are typically high compression, short stroke, and of course have a fair bit of valve overlap at high rpm (and about a million other things) :)

*trying not to be long winded here*

With forced induction, just the high compression (causes detonation) and valve overlap alone will already compromise running higher levels of boost.

an interesting setup is those typically run in low boost turbo applications in euro cars like the Audis. They have a small turbo running low boost. so it spools up real quick, but they engines also have a relatively high compression ratio (around 9~ish) so that when its off boost its still really responsive. These cars were never made to make high power (around 110kw out of the 1.8T) but had huge amounts of mid range torque.

So... if you're gonna turbo your Honda with stock internals, the best application is a low boost setup I reckon.

;)

Chris

[Weq]

Kit: i did the conversion myself. EVERYONE asks me if i bought this from some guy in Sydney (northern suburbs i think) :) He must of advertised that thing everywhere, cause its the first thign ppl ask !

[Kit]

Kit: i did the conversion myself. EVERYONE asks me if i bought this from some guy in Sydney (northern suburbs i think) :) He must of advertised that thing everywhere, cause its the first thign ppl ask !

oh ic.
cos my friend had a VTi civic sedan, burgandy too, and he did a turbo conversion. and he just sold it not long ago. he is from the western suburbs tho, just wondering if you were the one that bought his car.

Obviously not :)

Chris

[BLKCRX]

Turbo plus Toda cam's = hmm LOTS of power !!!

Cam's make more power simple ;-) even more with a turbo !!


Regards James

[wynode]

Turbo plus Toda cam's = hmm LOTS of power !!!

Cam's make more power simple ;-) even more with a turbo !!


Regards James

Any more info re turbos and short vs long(er) duration cams?

[Chi]

Kit: i did the conversion myself. EVERYONE asks me if i bought this from some guy in Sydney (northern suburbs i think) :) He must of advertised that thing everywhere, cause its the first thign ppl ask !

I was going to ask you taht very same question , Cause a guy had the same model same colour and a turbo setup for sale a while back.

And the outside was stock like yours.

[Kit]

Kit: i did the conversion myself. EVERYONE asks me if i bought this from some guy in Sydney (northern suburbs i think) :) He must of advertised that thing everywhere, cause its the first thign ppl ask !

I was going to ask you taht very same question , Cause a guy had the same model same colour and a turbo setup for sale a while back.

And the outside was stock like yours.

yeah, that guy that was selling it was a guy i used to work with. it was really torquey, i think he was running 7psi. I drove it once and it felt great, mid range was awesome.
he did a fair bit more to the car after i drove it and i'm not sure what configuration he ended up selling it for.

Chris

[VTi-RT]

Extreme turbo cars now go for N/A similar cams and rely on the turbo to keep boost up. Some also remove the VTEC lobes so you loose the vtec.

If Street turbo cams, it's higher duration and low overlap.

N/A cars it's High everything.