Keep IPS 272 cams in with my setup or use stock?

[Andr3w]

A while back I picked up some ported heads with high rev springs and IPS 272 cams in them and am not sure if I should use them or use the stock cams. What do you guys think? The turbos I have are the Billet DR650s and will be using E85 which will be controlled by a Pro EFI 128 ECU.

Andrew

[J. Fast]

For a turbo that small you don't need a cam. Unless you're going to boost 30psi or more keep the stock cam. You need at least 9:1 static compression or need more displacement. E85 is your best bet and put the stock cams on those heads.

[Fakepower]

Virtually nothing is known about most aftermarket cam setups out there ... by that I mean actual real world performance. There are no dynos or many hands on experience with them. However that said, I would encourage you to give them a try. The 272's on paper could have a ton of potential.

Also a turbo doesn't change what type of cam you want, desired power band does.

[J. Fast]

Explain to me why delaying torque on a 2" diameter exhaust wheel is beneficial when the max boost before knock is under 30psi ? With a hotside that small the backpressure is ridiculous. The last thing you want is overlap. The turbo he's selected will max out before there's any major gains to be had with that grind. Tiny TD04's typically don't develop much power at 8500rpm at 25psi (they love to taper early because their backpressure is so dam high). In the range that grind is spec'd what you stand to gain is detonation and pushing coolant if you try to crank the boost up or rev it out.

[fullracegt]

Stock cams for td04 cars!

[Fakepower]

Explain to me why delaying torque on a 2" diameter exhaust wheel is beneficial when the max boost before knock is under 30psi ? With a hotside that small the backpressure is ridiculous. The last thing you want is overlap. The turbo he's selected will max out before there's any major gains to be had with that grind. Tiny TD04's typically don't develop much power at 8500rpm at 25psi (they love to taper early because their backpressure is so dam high). In the range that grind is spec'd what you stand to gain is detonation and pushing coolant if you try to crank the boost up or rev it out.

Proof that the power band is that constrained to the extreme upper RPM band? I'm a believer in dyno's. Mathematical calculators from websites are not accepted.

[donniekak]

Explain to me why delaying torque on a 2" diameter exhaust wheel is beneficial when the max boost before knock is under 30psi ? With a hotside that small the backpressure is ridiculous. The last thing you want is overlap. The turbo he's selected will max out before there's any major gains to be had with that grind. Tiny TD04's typically don't develop much power at 8500rpm at 25psi (they love to taper early because their backpressure is so dam high). In the range that grind is spec'd what you stand to gain is detonation and pushing coolant if you try to crank the boost up or rev it out.

The best cams for small turbos are high lift 264's. You are right about overlap being bad in a high back pressure setup. But, you can increase the time the valves are effectively open without overlap events. A fast ramp rate, and high lift give you more flow, without the longer duration that brings overlap, and higher exhaust manifold pressure into play with excessive reversion. Adjustable cam gears also let you set the lsa so that you don't have inert 1300* exhaust gas blowing back into the cylinder, and creating pressure for the intake charge to fight against.

[J. Fast]

hpw

Proof that the power band is that constrained to the extreme upper RPM band? I'm a believer in dyno's. Mathematical calculators from websites are not accepted.

Ian at FSR can speak to my point of view...

08-28-2012, 05:47 PMHey guys i finally got my car back from fsr. Ok so heres the news. I have dr650 with aem ems. The block is all forged internals.I have bc 272/272 cams in the valve train that does not match the turbos. The cams make a ton of low end torque but cant breath enough with such a small turbo i willl definitely be going back to stock cams soon and the bc 272 will b up for sale for about 600ish obo. If u want the 272 pm me and we will set something up but please anyone with tdo4 these r not the cams for u. This cam is for biiiggg turbos only. So says ian at fsr a tuner masterOk back to my car. Ian was super cool the hole time really helped me out with the build and i would go back there any time and would recommend them to anyone whos looking for the best performance out of there car. Im runing 19psi with 650 injectors. Ian said with the torque im producting i should easily make well over 400 with a fmic. Im running stock nd there was some heat soak amd knock over 19. But i was overall extremely happy with what got done and how i was treated. If u guys have any questions id love to asnwer them. Im so juiced thay i have my baby back again. Got the car back Friday and i have already put 700 miles on it

my cars back from fsr finally with dyno sheet [Archive] - NorCal3S.com Northern California 3000GT/Stealth Owners Club

I own a 272 cam'd car and have tuned several. Most power I developed was 450whp uncorrected.

What results do you have to share Fakepower?

[J. Fast]

You want results Fakepower? Here's what my uncorrected results looked like in 2009 on a 272 cam with DR650's at 19psi at 6000ft above sea level. See how late the tq and hp peak? See how quick the tq and horsepower crash? That right there is called boost taper. It's the result of increased overlap. 272 is a terrible cam choice for a TD-04 framed turbocharger with an old school turbine wheel. If you want to know what this graph looks like at see level multiply it by 1.19. That was the correction factor that day. I don't really care about SAE numbers tho. I like real time numbers.

[familyMAN]

. If you want to know what this graph looks like at see level multiply it by 1.19. That was the correction factor that day. I don't really care about SAE numbers tho. I like real time numbers.

Can you post your 700hp billet td05 dyno? I have asked a couple times now in various threads.