N/A exhaust cam work in Turbo car?

[hubz91talontsi]

Ok so i have some n/a cams out of a parts car...I`ve done some research and the grind is 256...stock is 248. Just wondering if it would work. Not sure if intake or exhaust maybe someone else can help me there. I hope its exhaust =P

USDM 4G63 (Eclipse Non Turbo) Stock 256°/248° 208°/204° .365"/.349" 9.27/8.86

 

[90laserRSfwd]

I'm sort of confused as to what your asking here? From what I think your asking... Would a non turbo cam from a 1g non turbo 4g63 work in a turbo 4g63 motor? If that's your question then yes it will work. Can you please elaborate a little more. As for knowing if it's the intake or exhaust cam. If it's the intake cam: they will be a notch cut into the cam on the opposite side of the cam gear. That notch turns the CAS. If there is no notch then it's the exhaust cam. You could always post a picture too...

 

[hubz91talontsi]

this is a dsm forum...no i wan't to know if my dads v8 vega cams will work in my car...=P

Thanks for the fast response and advice im gonna look right now

 

[hubz91talontsi]

Ok so i found my intake cam...how do i know which one is the 256*

 

[JusMX141]

It is my understanding that the turbo cam is designed and degreed from the factory with the intent that a turbocharger bolted to the exhaust manifold is going to create more backpressure than a non-turbo engine with just an open manifold. The opposite would be true for the non-turbo engine which would need more backpressure to make torque in the lower RPM range....it would require an exhaust cam that allows more backpressure or the car would feel slow as balls until 5k.

By using a non-turbo exhaust cam on a turbo engine, you would theoretically be adding more backpressure....and I have no idea why you'd want to do that in terms of performance. It may pull hard into boost, but after that you'd run out of power quickly.

It may be possible to degree the cam a bit to add overlap and reduce backpressure using an adjustable cam gear, but while you're in that deep you might as well buy a set of cams.



Lots of good cam info from Wisemen and others in this thread:

http://www.dsmtuners.com/forums/cyl...cams-camshafts-camshaft-degreeing-timing.html

 

[hubz91talontsi]

But Justin the grind is bigger..It would be a 256/248.
Ok then answer this Justin because i know your a smart guy you`ve helped me in the past..Which is cam is better 4g63 cams or 4g63b cams on the stock evo's? I know both are the same(248) but evo has a higher lift...Lift better for top end?

Both sets of cams.. Turbo and non turbo which is better
Adv. Dur. Dur @ .050 Lift (in) Lift (mm)
USDM 4G63 (Eclipse/Talon Turbo) Stock 248°/248° 200°/200° .349"/.350" 8.86/8.89
USDM 4G63 (Eclipse Non Turbo) Stock 256°/248° 208°/204° .365"/.349" 9.27/8.86

 

[hubz91talontsi]

Ok well steve said

Intake NT opens 26 BTDC close 46 ABDC lobe height 35.493 (34.993 limit)
Intake MT opens 21 BTDC close 51 ABDC lobe height 35.493 (34.993 limit)
Intake AT opens 21 BTDC close 51 ABDC lobe height 35.200 (34.700 limit)

Exhaust NT opens 55 BBDC close ATDC 9 lobe height 35.200 (34.700 limit)
Exhaust AT opens 55 BBDC close ATDC 9 lobe height 35.200 (34.700 limit)
Exhaust MT opens 55 BBDC close ATDC 9 lobe height 35.493 (34.993 limit)

From this I come up with the NT intake cam being 252 duration, the turbo intake at 257 and a duration of 244 for the exhaust. NT has 35 degrees overlap (26BTDC + 9ATDC) and turbos have 30 (21+9). These are seat timings. From the point where the valve first starts to move.

Is my math correct?

Its a 256 and 248...but what he said about the intake cam..Does that means its better? hah

 

[90laserRSfwd]

turbo cams are designed for a turbo motor, they have more over lap, longer duration, etc. (there's alot more that goes into camshaft selection then just advertised duration and lift). What is done to the motor this is going into?

 

[hubz91talontsi]

SBR stage 1 with big 16g at 21psi stock side mount

Edit: Obviously if its not worth it..it won't be seeing the motor

 

[SnowBird]

I just went through a nightmare of having N/A cams in my TURBO. Dont do it, its just a pain in the ass, you can pick up used turbo cams for $20 a set, put the right cam in it.

 

[JusMX141]

Which is cam is better 4g63 cams or 4g63b cams on the stock evo's? I know both are the same(248) but evo has a higher lift...Lift better for top end?

I honestly don't feel lift does as much to effect power output in a forced induction application as, say, duration or overlap. While lift merely effects how far the valve opens, duration and overlap both effect how quickly exhaust is removed and how effectively the clean air charge is brought into the cylinder. Your cams could have crazy amounts of lift, and you're not really going to gain any power unless something is done to modify when the valves actually open.

Perhaps someone with more cam experience could add to this.