RB26 Tomei Type R Cams - Results?

[No Crust Racing]

RB26 Tomei Type R Cams - Results?

Trying to find some concrete info around the expected gains from these cams, 250 duration, 9.15mm lift. 

I've got a -9 setup car on e85 with all the usual stuff, including cam gears, dyno below,  

I'm mostly interested in response and low to mid range torque, though some more top end wouldn't be a bad thing, I just don't want it at the expense of low to mid range, it's a street car. 

Has anyone personally used these cams in a similar setup car and what was the result? I had a hard time finding anything solid in the dyno thread, as I'm interested in specific before and after from the cams themselves. 

I realise the notes around these talk about them being used on stock cat cars to minimise backpressure, I don't have a stock cat and I have full 3.5" from the merge. 

Edited October 6, 2016 by ActionDan
Changed word order to make more sense.

[GTSBoy]

No actual numbers from me, but if I were predicting.......

I would imagine that it 100% depends on how they are dialled in.  You can probably get them to improve response with a zero to small increase at the top also, or you can set them up to give a decent improvement towards the top end with a likely small negative effect on the bottom end.  Look at it this way.  You have a bit more duration than stock, but not too much, so you can arrange for that duration to provide more overlap or probably about the same overlap as stock.  You have more lift, but not a lot, so you will improve flow everywhere by a little bit, in isolation to the effects caused by the duration difference.

[No Crust Racing]

Theory is nice, but I'm keen on numbers and yes I realise how they are dialed matters also. 

I see most people just go Type A or B, but many have gone from A/B back to stock with much better response/mid range as a result, but without knowing how they were dialled intiially (for mid or top end etc) it's hard to confirm why that result was achieved. 

That said, can a Type A be dialled primarly for response/mid range, but still benefit the top end due to the increased duration? 

I'm very cautious of lowering dynamic compression and making the off boost drivability even worse than a little 2.6L in a big car already is. 

 

[owen1r]

6 minutes ago, ActionDan said:

I've got a -9 setup car on e85 with all the usual stuff, including cam gears, dyno below,  

I'm mostly interested in response and low to mid range torque.

There's your issue.

But on srs note, I think SimonR32 ran those cams and many others. Shoot him a PM.

 

[No Crust Racing]

Sorry I don't follow? I thought we'd all agreed that -9s were relatively responsive? Or is this a lead in to telling me to go single I'm in Vic, not happening. 

I'll try Simon, cheers. 

[owen1r]

Single pls, in saying that I have silly 272s in my car and off boost is still awesome and you get to sound tough at the lights.

I'm really not sure how VIC compares to WA, but surely engineering/mod plated wouldn't be too much trouble.

[No Crust Racing]

We're already heading away from my question, which is about Type R Cams, and maybe A, results in terms of response and mid range

 

[admS15]

3.2l bottom end. Torque for weeks. Lol

[No Crust Racing]

You fund it, I'll do it. 

Again, just want to talk about cams

[mr skidz]

Low to mid was what I was targeting as I knew the RB would never lack top end regardless of cam choice so Type A it was.

Wouldn't change a thing.

[No Crust Racing]

Any before and afters? 

What setup? 

[mr skidz]

I would choose std cams over type bs

[No Crust Racing]

We're not talking Type Bs here for anything, 

R or A, max. 

[mr skidz]

Any before and afters? 

What setup? 

Sorry no before after comparison's but throttle response is very snappy right off idle on a 2.738

[No Crust Racing]

More capacity too which makes it a tougher comparison, but thanks for the input. 

[mr skidz]

Peak torque moves further away as duration is increased so do the opposite [emoji6][emoji108]

[mr skidz]

Don't quote me on this I'd have to dig through my archives. you might want to just double check but pretty sure Z Tune R34 ran type A spec cams and it ran same crank spec as mine too

[No Crust Racing]

Thanks for the info, 

I know too much duration can be an issue at low RPMs, but the question is what is "too much" in an RB26. 

Is 250 going to be too much or is that small enough of a bump up to improve mid to high rpm performance without losing anything down low or is there no such thing as a gain in the low/medium/high and anything you do is just moving the band left or right and that's that. 

Who else has used Type Rs? 

[mr skidz]

More capacity too which makes it a tougher comparison, but thanks for the input. 

In terms of duration in the camshaft I'm not sure capacity makes that much of a difference you're just a shifting your peak torque closer or further away yes the stroker will have more peak torque but where it is in the RPM range is what you're after not the actual number

[KiwiRS4T]

You will be lucky to find anyone who can give you a before and after comparing type R with stock cams because usually (not always) people incorporate new cams in a new build. There's nothing wrong with sound theory - a modest increase in duration and lift should, if tuned right , give you a modest increase in power up top. Increased duration should work against response low down.

 

I would keep the stock cams and get a better single.