RB26 Tomei Type R Cams - Results?

[SimonR32]

I've gone from either 256 or 260 Greddy cams to 250 Tomei Type-R's. We matched the response but lost a few ponies top end (probably 20-30hp on moderate boost and 50-60hp at the higher end). I'm actually a little disappointed but now thinking I'll chuck in a set of Type-B 260's that I have sitting at home to see if they are better suited. It's also not a completely scientific comparison because my old head had the intake squish removed and aftermarket head gasket that would have played with compression but I would have thought that would make it laggier if anything.

[No Crust Racing]

At what power/boost are we talking? 

[SimonR32]

4 minutes ago, ActionDan said:

At what power/boost are we talking? 

1.5bar was around 600, dropped to 580 and 2bar was 740, now around 690hp

[No Crust Racing]

Twice as many wasps as me. 

They don't sound like a good fit for you if they only matched the response. 

[Trex]

This guy may have some info you're after, Dan.

 

 

[No Crust Racing]

We've chatted, in the end I think I might try and fiddle with the cam adjustment more and leave it as is given the total cost to fit and tune vs expected gains. 

[mr skidz]

What's the current setting on the cam gears

[No Crust Racing]

I can't recall off the top of my head but I think it was something like 2 deg advanced on the intake and 4 deg retard on the exhaust. 

 

 

[Darmanin10]

What size cam would you guys recommend for a stock rb26, twin scroll gtx3576r on e85

I initially planned on keeping standard cams, after reading they are the best choice for response, but while the arp head studs and cam gears are going in, may as well drop in some cams while i'm there?

 

[r32-25t]

For everyone one that wants to argue the effect a bigger set of cams will have on an engine this shows perfectly what they do

note the duration increase of 20° which is very close to the same as tomei type Bs into an rb26

 

[No Crust Racing]

Very informative, good post

My car goes in Tuesday for Cams and Springs, we'll see how it ends up. 

 

Edited April 5, 2017 by ActionDan

[jet_r31]

On 4/3/2017 at 10:13 PM, r32-25t said:

For everyone one that wants to argue the effect a bigger set of cams will have on an engine this shows perfectly what they do

note the duration increase of 20° which is very close to the same as tomei type Bs into an rb26

 

except you have a turbine housing and turbine wheel in the way of the exhaust flow which is the biggest bottleneck in making power..and revs..in a turbocharged motor

and is more often the power/rev  cap ...and not the camshaft, more duration just does nothing in that scenario apart from shorten the powerband..

[r32-25t]

I was more showing the way it reduces the bottom end and mid range, but everyone in the thread has tried to say that's not the case. 

Yes you will get no where near the improvement up top that engine did and the bottom end/ mid range torque loss will be considerably worse due to only having 2.6L instead of the 6.2 to help hide the issue 

[KiwiRS4T]

On 6/12/2016 at 10:07 PM, Darmanin10 said:

What size cam would you guys recommend for a stock rb26, twin scroll gtx3576r on e85

I initially planned on keeping standard cams, after reading they are the best choice for response, but while the arp head studs and cam gears are going in, may as well drop in some cams while i'm there?

 

No that's not a reason to drop in some cams (because you can). You need to have a reason in that you know what effect they will have and that its an effect that you want.

[Darmanin10]

On 4/10/2017 at 6:12 PM, KiwiRS4T said:

No that's not a reason to drop in some cams (because you can). You need to have a reason in that you know what effect they will have and that its an effect that you want.

Was always a toss up, whether i get cams or not. Half the people swear by standard cams, half the people say cam upgrades are must haves.

My tuner strongly recommended I upgrade to Tomei Type b's, while he was putting in the head studs, because I told him i was undecided. I wanted a responsive street package, and paired with a twin scroll gtx35 , it is just that.

[Dose Pipe Sutututu]

Get cams that provide more lift as that will produce power, duration will move the power band to the right. 

So (I know Lithium will have a different view) get cams that provide a little bit more duration so the power doesn't nose over early and find ones that provide the most lift possible with your setup (ie head constraints)

[No Crust Racing]

That's why I went the kelford, better lift and ramp rate than type B.

[djvoodoo]

On 14/04/2017 at 9:45 AM, ActionDan said:

That's why I went the kelford, better lift and ramp rate than type B.

Any update on the final results yet?

[No Crust Racing]

Car blew up on the dyno. 

Nah, Cams turned out to be for R33 CAS (neither seller nor I realised this, woops) it should  arrive at Kelford today/tomorrow for modification then be sent back. Expect results next week

 

[MJTru]

I like this thread seem like it's right up my alley. So from what I see here a cam with longer duration kills the bottom end. In short if you were to advance the cam, using a adjustable cam sprocket will help out a little bit. But how does a cam with lots of duration relate to ignition timing.

I must admit that I haven't looked over all the comments as I'm at work now. But I sure will put it on my to do list to night.
Great thread.