Are Cams A Worthy Investment On A Rb20?

[quincy777]

Hi all, I am wandering whether this is a good move or waste of money. I already have 220 RWKW from my RB20? Should I just get a RB25 for further upgrade or do cams make a good difference at this level for dollars spent?

Cheers

[Jago]

depends on what you already have done and what else you are planning on doing. But i'd sure as hell do it But that's just me

With the right cams you'd expect to pick up better power delivery throughout the rev range and a bit more top end. So it's worth it in my opinion. Im definately camming mine up

[barnoon]

Im wondering the same thing myself thinking of doing cams or even just cam gears on my RB20 see if I can get her spooling up a bit earlier (currently hits full boost around 5500rpm)

[Jago]

Im wondering the same thing myself thinking of doing cams or even just cam gears on my RB20 see if I can get her spooling up a bit earlier (currently hits full boost around 5500rpm)

Well, in regards to JUST cam gears, i haven't heard great things about it on 20's. Infact i've heard that Roy tried it, and said he gained basically nothing. I think it was somewhere in the top RB20 thread.

If you have the money, and want to see best gains, just go cams and cam gears, and go get the setup tuned.

[rev210]

always.

[Roy]

I think the guys that first tuned my car struggled to get anything out of cam gears. The guy that later tuned the car got more power everywhere out of the setup at the same boost with a smaller exhaust housing. So you would expect it to be more responsive with the smaller housing...but it even makes more power up top so the tune is on the money ... and the cam gears have been tweaked.

I have some cams that i may try in the RB20, i keep changing my mind as i want to run it at the drags without the cams but with a good diff . The tune needs a tweak for the 23psi i will be running (may as well get it tuned for the Shell 100) and want to see if i can get a decent time out of a std RB20 engien and gearbox

Cams may come later if the engine is still alive and has good compression. I just dont want to run the risk of hurting the motor with cam journals etc seizing again like they did on my last engine. Too much agro and im on a tighter then ever budget Id rather then cams jsut sit idle in my room for the tiem being.

LOL..how close can an RB20 get to an 11.99999 1/4 mile

[Jago]

I think the guys that first tuned my car struggled to get anything out of cam gears. The guy that later tuned the car got more power everywhere out of the setup at the same boost with a smaller exhaust housing. So you would expect it to be more responsive with the smaller housing...but it even makes more power up top so the tune is on the money ... and the cam gears have been tweaked.

So you DID end up gaining something? I remember you saying in the top RB20 thread that you were on the "normal/standard" settings, well, found they were "best"

[Roy]

Yeh thats what the first tuner told me/experienced. A more recent tuner seems to have set them to get more out of it. I seem to have little more top end (doesnt taper off so quickly) compated to other stock cam'd RB20s???

I dunno, give it a try. Just make sure your tuner is good and it seems you will get results. Quincy...i suggest you talk to the guy that tuned it and get his feedback on whether there is any point

[RedDrifter]

If you go just the stage 1 pon cams I wouldn't bother getting cam gears as Tomei set the cam timeing on those for all best round performance.

Though it depends on your setup I suppose.

I'm saveing my cash for a set atm.

[rev210]

If you go just the stage 1 pon cams I wouldn't bother getting cam gears as Tomei set the cam timeing on those for all best round performance.

Though it depends on your setup I suppose.

I'm saveing my cash for a set atm.

Tomei don't say that and it's not true either.

Plenty of people with the poncams testify to that not being the case. Including myself.

[RedDrifter]

Tomei don't say that and it's not true either.

Plenty of people with the poncams testify to that not being the case. Including myself.

Yes they do. Please read.

This is the first paragraph from the pon cams section on he Tomei site.

Valve timing is opening and closing timing of intake and exhaust valve that are linking to the piston movement,　and it is expressed with the crankshaft angle from TDC or BDC of the piston. When installing new camshaft, idle stability or low-mid range torque are dramatically charged by 1°degree of valve timing adjustment that controls overlap or valve closing timing. Valve timing is usually adjusted by engine-tuner who is working on with the test driver. So as PONCAM, the best duration timing and the valve lifts are decided from torque characteristic and acceleration data that is based on huge numbers of tests both on the bench actual running. Accordingly, dowel pin is shifted to the proper position at the same time.

You'll get the best valve timing without any adjustment but just a replacement of the factory camshaft with PONCAM.

Poncam

You will need to select the poncam tab once the page is loaded.

Now the thing is this is probably more true for a stock turbo etc. When you upgrade the turbo you whole power band changes depending on the turbo characteristics and then you will need to adjust the cam timing to suit the new power band etc. Tomei state similar down the page.

I wasn't misleading people I was just restating what Tomei claim.

I know I won't be bothered getting the adjustable cam pullies as for a few extra kw's I couldn't be f!@#k'd.

I just want the better/larger power band.

Cheers!

Edited February 8, 2007 by RedDrifter

[R31 POWER]

Roy sell me your cams

[sinistaGTR]

Im wondering the same thing myself thinking of doing cams or even just cam gears on my RB20 see if I can get her spooling up a bit earlier (currently hits full boost around 5500rpm)

What you only get 200rwkw and hit boost at 5500rpm sounds like a nice car to drive......

[quincy777]

For those that don't know my car, the 220rwkw is with basically everything already upgraded - nothing else left to do (even run spit fire coils). I have had a larger turbo and got 257rwkw but street driving was crap compared to GT28RS turbo setup I have now.

SO I want to know If i buy the pon cams or similar is anything going to change? how soon it comes on? higher RWKW figure and better drivability. A monent full boost before 4rpm and holds to 7750 RPM.

From responses so far sounds like waste of time and money for no significant improvement.

[rev210]

This is the first paragraph from the pon cams section on he Tomei site.

So as PONCAM, the best duration timing and the valve lifts are decided from torque characteristic and acceleration data that is based on huge numbers of tests both on the bench actual running. Accordingly, dowel pin is shifted to the proper position at the same time.

What I know about camshaft timing agrees with the quoted parragraph Tomei has at the begining which I think you didn't understand properly.

The last sentence is 'not' an instruction for timing the cams perfectly on any RB engine they make a cam for. The preceeding parragraph says more about that. Although I can see how it mislead you.

It's a Jap --- english translation and as usual not as clear as it could be.

Now as for small gains.. .I've seen more than 100+rwhp on one occassion from moving the Tomei 260 9mm poncams from the 0 to something more suitable. My old GTR picked up power everywhere both with factory turbos and Group A's over and above the 0 setting.

Slapping cams in without making adjustments is a 'bolt on boy' approach I have seen go wrong for people even back when I was runnning about with pushrod V8's. I always invested in adjustable timing gears then just like now. You won't see a big dollar RB motor without them if the engine builder is serious. The best cam timing is something for your engine setup and application (both count).

So it's not a silly thing to get cam gears afterall. You aren't wasting money. You are getting full value out of the cams.

Just trying to help with what little 'real' experience I have as opposed to opinion.

If it doesn't make sense ask your engine builder what he thinks.

[Jago]

For those that don't know my car, the 220rwkw is with basically everything already upgraded - nothing else left to do (even run spit fire coils). I have had a larger turbo and got 257rwkw but street driving was crap compared to GT28RS turbo setup I have now.

SO I want to know If i buy the pon cams or similar is anything going to change? how soon it comes on? higher RWKW figure and better drivability. A monent full boost before 4rpm and holds to 7750 RPM.

From responses so far sounds like waste of time and money for no significant improvement.

christ, my 20DETT don't even have anywhere near that much lag

[barnoon]

sinistagtst Posted Yesterday, 06:43 PM

What you only get 200rwkw and hit boost at 5500rpm sounds like a nice car to drive......

Its very fun to drive, thats in 2nd gear im not sure where it hits in the higher gears

Edited February 8, 2007 by Dave69001

[ellie]

If it is of any use, that performnace handbook with the WRX on the cover has a dynoed test that shows an RB20 with standard cams had its exhaust cam retarded 6 degrees (don't quote me, check it out yourself) and inlet advanced 2 degrees using cam gears which gave a little less on take off but a 20% power gain higher in the rev range.

Again - can't remember exactly. Maybe someone on here has that book!

[RB GUN]

quincy777- mate ill tell you this. i have had an RB20DET in my GTRST b4 and the mods i had was:

Custom Zorst Manifold

GT3040R with .63 housing

Sard 550cc

EMS stinger

bosch 910 fuel pump

forrged pistons (Arias)

Custom FMIC

Now, i was running 1.5 bar of boost and she made 230rwkw. I ordered Tomei 256 with 9.5 lift cams that was for an RB25DET engine and my mechanic fitted them. then car was tuned at 1.2 bar boost and made a 261rwkw.

The point is that i invested $1500 that was NOT a waste.

Cheers

Babak

[fr0st]

MRPREZ, are you hitting 1.2bar at the same amount of revs or did the cams help it spool a bit better?