Small turbos and cam selection

[JOEY A]

Well ive always thought it might have been better with my evoIII if I would have gone with straight 264s instead of 272s....

I think the 264s would have matched the turbo better, and make the power band a bit wider, ive scene dynos of T28 240s with big vs little cams

Most of the time, you see the 272 is a bit peaky and the 264 makes almost the same power with a wider range

Anyone else would like to chime in on this....Ive never drivn a car with 264s so this is just a idea im throw out there....

 

[pboglio]

Well ive always thought it might have been better with my evoIII if I would have gone with straight 264s instead of 272s....

I think the 264s would have matched the turbo better, and make the power band a bit wider, ive scene dynos of T28 240s with big vs little cams

Most of the time, you see the 272 is a bit peaky and the 264 makes almost the same power with a wider range

Anyone else would like to chime in on this....Ive never drivn a car with 264s so this is just a idea im throw out there....

I run HKS 264's straight up, on a T28. I can't compain, they idle nearly like stock, pull 18-19" HG vacuum, great spool up and low end torque, and they hit hard in the midrange. My power band starts at about 3700 rpm and goes strong to 6500 rpm or so, with peak torque hitting right around 4700-5000 rpms. I'm layin down about 342 crank h.p. / 330 lb-ft torque on 21 psi (according to DSMLINK). I'm thinking of dropping in the HKS 272 exhaust cam to pick up a little more topend. Yep, 264's make for a nice daily driver.

 

[damnslowtsi]

I installed my 272s back when the car had a 16g in it. On a consecutive trip to a track I lost about 2.5-3mph. After that I went to LACR few more times over the course of a few months trying different tunes and never regained mph of stock cams. This may sound strange as I 'm sure there is a bunch of folks who ran better with 272s and similar sized turbos but that's my story. I tend to think the reason for that was that 16g develops pretty high backpressure when squeezed to the limit and it didn't mix well with longer duration/overlap of the cams.

 

[Steve93Talon]

I ran my 12.1 @ 112 on the 14b with HKS 272s, but on the dyno my power still fell off a cliff over 6k, so obviously they weren't doing anything up top with a small turbo. I would've loved to have compared them to stock or 264s. There's an old dyno comparison with 264s, 264/272s, and 272s on a 16g that indicates that the 264/272 setup would be best for a turbo that size.

 

[JOEY A]

I ran my 12.1 @ 112 on the 14b with HKS 272s, but on the dyno my power still fell off a cliff over 6k, so obviously they weren't doing anything up top with a small turbo. I would've loved to have compared them to stock or 264s. There's an old dyno comparison with 264s, 264/272s, and 272s on a 16g that indicates that the 264/272 setup would be best for a turbo that size.

Thanks for posting up the graph

 

[T9S1i]

I run the "DKS" 264/272 combo from FFWDconnection.com which are pretty much the same thing as hks 264/272 and i love em on my small 16g. I didnt feel like i lost any low end and the midrange and top end are a lot better. It really felt like it opened up from 4k up. The car pulls well to 7k im sure it will pull hard past 7k, but i doubt its really making that much more power. I have no hard dyno #'s but my good ol' butt dyno told me that its making better power now.

For track #'s...I ran a 14.0 with about 12-13psi before the cams. I added the cams and 2psi of boost (to 15psi) and went back to the track and ran a 13.5 on an old tired motor (a couple weeks before it blew). It could have been the cams that added a significant amount of power, or it could have been a better tune, im not sure but they did help.

My advice, if you are going to run a street dsm and dont want to upgrade above an Evo 3 16g (never really going to have to rev past 7k) get a 264/272 combo. If you plan to run a larger turbo than a E316g get 272's (i.e. makes good power above 7k). 264's if you live in a smog nazi state and want to get that extra umph out of your 14b setub while still being "ok" for emissions.

 

[JOEY A]

Why such low boost? Your bound to get 12s out of it with some more

 

[Strm Trpr]

I run the "DKS" 264/272 combo from FFWDconnection.com which are pretty much the same thing as hks 264/272 and i love em on my small 16g.

I see you're here in good CA.
Did you ever smog your car with this set-up?

 

[T9S1i]

Why such low boost? Your bound to get 12s out of it with some more

91 octane, and supporting mods. The motor was tired, i blew it like 2-4 weeks after that day.

On the new motor though, (specs in profile) weisco 8.3/skat rods BSEK la la la... I went 13.7 at 10psi and 12.9 at the same 15psi with 50/50 mix of 91/100 octane. I started the day running 13.4 and 8 runs later without touching the tune i drove the piss out of my car and hit the 12.9. (8 runs... 13.4, 13.3, 13.2, 13.2, 13.2, 13.008(my first 1.7 60ft), 13.2, then finally the 12.9@104!!!)

Thats where im at now, there are a few misc maintenence things i need to do and im need to fix my AFRP (i ran the 12.9 on the stocker) and bla bla bla you know usual dsm stuff. The car has a lot more in it. Im hoping to break 12.5 with 20ish psi. IF i do, i'll be happy with this turbo, call it a success, and upgrade!!!

I see you're here in good CA.
Did you ever smog your car with this set-up?

Ha.. tried to smog it but i had a CRUCIAL exhaust leak from ex mani/head gasket so my nox readings were through the roof... i had to go ahead and smog it the "old fashioned" way. So im good for 2 years now.

 

[dsm-onster]

Research ShapeGSX. The first around here to go 11s w/ the evo3 16g. He reported minimal difference betweent he 264s and 272s and also w/ combinations (264/272, 272/264). He noted not loss in power down low w/ the 272s vs. 264s. He also noted no increase in power up top w/ the 272s vs. 264s.

I've run these FP2Xs for several years w/a small 16g and a tdo5h 18g for years and the "streetability" has been consistant between the two and surprisingly positive vs. stock cams. I was very happy w/ the 272 like cams w/ both turbos. Of course, the stock cams made me FEEL like I had lots of unbridled torque, but in reality the power band was broader (though higher) for the FP2 cams w/ BOTH turbos. The 18g yielding much more but still the small 16g had more usable power for a broader rpm range.

There is a significant difference between the 18g and the small 16g, so I like to think that I got a good duration for the street AND for later growth. It has been apparently true considering my last logs w/ a much bigger turbo.

264s are surely an upgrade for stock cams. But, after a 14b, 272s are always better, there's little to no loss of drivability between the two cams and the 272s yield enough VE at high enough rpms to max out more turbo.