Turbo vs N/A Cams Dyno Compare

[88YotaTurbo]

I have seen much discussions over which is better to run for performance and here are the result. no A/F readings were saved to file for some reason. video page 5

Graph 1 : Turbo cams 12psi BPU(intake ,full exhaust, bov, everything else stock)
Graph 2 : N/A cams 12 psi BPU but bosch 110... a/f reading ~10.5
Graph 3 : N/a cams 15 psi BPU.... a/f ~ 11.5-12 Block off removed, stock afm
Graph 4 : N/A cams 18 psi BPU.... a/f ~ 12 " "

 

[logan]

That's pretty neat , good job , the N/A has an early torque gain , but dies after that . I wonder which one is faster ?

BTW , Could you do a brian crower comparison too.... please

 

[BorHor]

Good info.

 

[86_sports_1jz]

looks like the turbo cams are better, but are they really?

 

[Datsrboi]

I guess if your a circuit track type person the NA cams are a better choice?

 

[Poodles]

more torque, less HP...

the only issue I see is that turbo cams tend to get worn out faster (rod knock, BHG, ect kill the lobes) so the N/A cams end up being better.

Which one will be faster? Turbo cams IMHO as it pulled hard till redline where the N/A cams fall off bad...

 

[88YotaTurbo]

N/A cams ftw < 15psi Turbo cams >15psi on the ct 26
For 15 psi I would have to say go for n/a because of the HUGE torque increase but less then 10 hp loss which you will not feel. You will definitely feel the torque.
This dyno run was with a blown turbo seal too I'll have video soon and you'll all see.

 

[88YotaTurbo]

I guess if your a circuit track type person the NA cams are a better choice?

Well I did notice a significant drop in my autocross times.

 

[TurboStreetCar]

eh, n/a cams are all down hill from 4krpm, turbo cams still make power real good till 5500rpm.

The n/a cams are very peaky, they make alot of torque at 3000rpm but its all down hill from there. the turbo cams make the same torque at 5500rpm as they do at 2750rpm and more in between, there more broad consistent and useable. Whats the point of making all your torque under 3500rpm when a decent sized turbo full spools between 3-4krpm???

You cant feel the loss of 10 hp, you cant feel horsepower at all, but you can feel the torque dropping off at 3krpm.

 

[Poodles]

area under the curve...

 

[p5150]

looks like similar results to the test that was done on SF a few years ago.

NA cams - good for smaller turbos and quick spool.
turbo cams - good for big turbos that require more rpms

 

[Poodles]

as I've said for some time, it would have been cheaper for toyota to run the same cams in both engines... it was done for a reason.

 

[86_sports_1jz]

both cams are good just depending what you want to use it for, turbo for drag and highway, n/a for auto crossing and drifting.

 

[Nick M]

So, what are the condition of these cams tested? Both new out of box, or both used with unknown wear and tear?

Otherwise, not to useful.

As already stated, it would have been cheaper to just use the same intake cam if it didn't matter.

 

[TurboStreetCar]

i doubt that normal wear and tear on a cam would drastically change the performance of the engine, there would have to be serious damage to the lobes to change them that drastically from each other......

anyone know the cam specs for lift, duration, and LSA while we re on the topic???

 

[shaeff]

wait until you start making serious power, and you'll notice that the N/A cams kill your top end. less lift FTL.

-shaeff

 

[thechori]

n/a cams for the dorifto ehhhh. me likey

 

[TurboStreetCar]

no specs i guess????

 

[88YotaTurbo]

The n/a cams were pulled from a freshly built head. The turbo cams are unknown wear. Drifting was a lot easier for me with the n/a cams. These graphs also show two things. Notice the loss in power at 18 psi compared to 15psi? The ct26 was blowing hot air after 15. It just didn't have enough air flow.
I will be changing back to the turbo cams because I like the high end. Plus I just got my first drive in a 1jz and I love the top end. I'm jealous and need to do a swap.

 

[gilberjj]

good info!