I've been reading the threads and from what I understand is,

1. Stock turbo should not really being using 272's or bigger since it would br too big for the turbo.

2. bigger turbos such as gt3037, gt35r, etc... can utilize the 272's or bigger so it's ok to put bigger cams.

3. Bigger the cams the rougher the idle.

Then here's my question,

If I wanted smoother idle would I go with a 264/272? Or how about if I wanted better spool up, would I want 272's? I currently have a GT35R on the Evo and can't decide which cams to choose.

Any advice would be appreciated..

 

It will depend on your tuner, you can get most of these big cams to idle like stock.
I have aem ems and 272/272 stock turbo, my car idles like a stock car.
Pick the cams you like to run with for your desired power. Obviously you will tune the car,
Idle is up to the tuner.( IF they know their stuff, they know how to get perfect idle)

 

either 272s or 280s, i think if you have an EMS, the 280s would benefit you the most for the GT35r

 

I would go for 280's with your gt35r. I have seen 30-50 more whp over the 272's with a 35r

 

I don't have any opposition with 272's or 280's just worried about idle and spool up. I'm getting AEM EMS next week. So the with the EMS, idle shouldn't be a problem as long as the tuning is correct? How about spool up? will the 272's or 280's increase or decrease lag?

 

I don't have any opposition with 272's or 280's just worried about idle and spool up. I'm getting AEM EMS next week. So the with the EMS, idle shouldn't be a problem as long as the tuning is correct? How about spool up? will the 272's or 280's increase or decrease lag?

 

read above

 

arn't the 272's the way to go if you want to a mix between strip and street

 

maybe with the stock turbo, but this guy's got a gt35, he's already beyond the "normal street" setup

 

Here's a list of what I have.

ATP's GT35R turbo kit
750CC injectors
255 LPH pump
Greddy profec B II
SAFC II
3" Turbo back exhaust no cat

My car with these mods gets full boost @ around 4800rpm or under. What I like to achieve is full spool @ 4000 rpm. Now what I'm upgrading is

AEM EMS
Tubular headers
Cams

I know the 280's will give me the most top end power, but what cams or cam combination will give me best spool up.

 

I would strongly disagree with that statement. I ran HKS 272s on my stock turbo ('03) for over a year and I was very happy with the performance. I had absolutely no camshaft related idle issues or driveability issues.

Agreed, a better flowing turbo will be able to fully utilize a more aggressive cam.

Not necessarily true. My HKS 272 setup, set to -4/-1, idled almost exactly like stock. Much better, for example than other Evos that I've seen with both 264 and 272 cams (but different cam gear settings). However, my current HKS 280 setup, set to +2/0, has a very lopey idle (sounds like a motorcycle).

Generally speaking the less aggressive cams (i.e. 264s) will spoolup earlier than the more aggressive cams (i.e. 272s), which in turn will spoolup earlier than the most aggressive cams (i.e. 280s). However, some of that can be dialed in/out using adjustable cam gears. Ted B, BadazzCR, and myself have posted some comparisons for cam gear timing results.

For a big turbo like the 35r, assuming a stock block (i.e. stock redline), I'd probably go with 264s if you want good spoolup, or 272s if you're willing to give up 100-200rpms of spool for better topend. However the 272s may be trickier to dial in, if you want to minimize the amount of spool you're willing to lose. The setting I ran with my 272s (-4/-1) sacrifices some additional spool for better idle and good topend. Of course, you could just be like "f**k it!", I'm going ***** out ... in which case HKS 280s at +2/0 would be the choice.

l8r)

 

well with the gt35, you're never going to have "great" spool up, and I think that the cams that would give you the "best" would be the lower #s, but then that also is working against the purpose of the big turbo, which is higher end power. I think... Someone else probably knows much better...

 

I will be very impressed if you ever get full spool by 4000rpms on a stock head and block, running a stock intake manifold. Don't get me wrong, it may be doable, but I think it's going to take more than adding the headers, AEM, and cams. The way I see it (these are just guesses here):
- AEM ... +200 rpm spool
- Tubular header ... + 200 rpm spool
- cams ... +0 to -200 rpm spool

Are you running a pump gas or racegas tune?

l8r)

 

Dont believe everything you read. Half the things you read on here are people who dont know what they're talking about and usually dont even have the parts they are giving you info on.

280s indeed add power to the STOCK TURBO. David Buschur has proven so, need I say more? Ill be adding 280s with cam gears soon.

 

Are you running a pump gas or racegas tune?



I have a 91 pump and race maps on the SAFC II