How much you can get with 7A cams?

[vcosmin]

@ a little offtopic high lift cams, but almost flat torque till redline, only 65mm inducer@ 23psi

[Jamo]

really? what cams are those?

[vcosmin]

Custom / Cat Cams + hand ported head !

[Rocco]

@ a little offtopic high lift cams, but almost flat torque till redline, only 65mm inducer@ 23psi

11 lift?

[prj]

Seeing these flat torque figures, part of me always thinks "not enough boost"
Unless it's knock limited of course.

[Rocco]

Seeing these flat torque figures, part of me always thinks "not enough boost"
Unless it's knock limited of course.

It's similar dyno draw like the one that Vadim had boosting 1.7 bar and 608 hp and 660 nm...and just max power where the rev limiter 7500 rpm

[Billman]

Not to nitpick, but dad's car is making about 30 more lb/ft and 20 more hp at 4krpm. And rst is also running another ~5-6psi of boost. A boost line would be nice on rst's graph to really see how they are spooling differently. But yeah interesting nonetheless how close they are with pretty different setups. I was reading quite a bit about compression ratios and as far as I could tell, a lower CR doesn't affect spool much but will drop HP once boost has built (dad running 8.5:1)


But regardless, my point was simply to say taht 600hp is easily achievable with 7A cams

No offence....It was just a tip to compare. Your build is very nice and I am following it on Motorgeek for quite some time now

[vcosmin]

Seeing these flat torque figures, part of me always thinks "not enough boost"
Unless it's knock limited of course.

Boost was limited of course to 1.6 bar , this map was on 0.68 AR ! With 0.81 AR and 67mm billet compresor, it did 680@1.5 bar@7500rpm. Cams are more than 11mm lift/solid lifters. Trap speed 231kmh@1300kg / this year i bet i will do 9s with this power.

What i wanted to say is that with a worked head, and good cams, you can have a quite good powerband, and very eficient engine (in the designed powerband)

I bet that a 72/74mm inducer will still work very good in my setup.
But money wise, for a mild setup 7a cams are best buy

[prj]

Boost was limited of course to 1.6 bar , this map was on 0.68 AR ! With 0.81 AR and 67mm billet compresor, it did 680@1.5 bar@7500rpm. Cams are more than 11mm lift/solid lifters. Trap speed 231kmh@1300kg / this year i bet i will do 9s with this power.

What i wanted to say is that with a worked head, and good cams, you can have a quite good powerband, and very eficient engine (in the designed powerband)

I bet that a 72/74mm inducer will still work very good in my setup.
But money wise, for a mild setup 7a cams are best buy

What I mean basically is, that your turbo could do a lot more than what you are doing now. Both from compressor as well as from hotside at lower revs.
If you look at how for example most cars from factory are tuned, their torque delivery is very flat also, because not all available potential is used.

It's like peak torque vs horsepower. Maybe you will not gain any horsepower, but you can probably gain torque.
One way to visualize this is to plot your engine on the turbo's compressor map.

This is not taking in account any other torque limits though. There are many good reasons to limit torque.
I hope you understand what I mean and don't take this the wrong way.

[vcosmin]

Of course i get the idea, dont worry. Torque is good, but to much makes problem - see the sheet . (central torsen)

Right now, we are limited by ignition (missfire at 1.8 - peak torque), and backpressure, on the other hand the engine was very reliable with the medium boost setup, no problems for a whole season

[prj]

Which coils are you using that you have misfire and which plugs?

[chaloux]

No offense taken at all! I actually didn't even really want to bring it up as it's almost negligible. What compression ratio are you using rst?

[vcosmin]

ik27 Denso / coils , close in specification tu 034 HO , i spoked with the sparktech guy to try his evo setup in I5 :-)

[prj]

Ok, because it is weird that you are getting this problem at 550nm.
Both brand new original coils, as well as 2.0TFSI coils can easily handle much more than this.

Have you tried increasing dwell time? Maybe it's too low? Or maybe you have a big voltage drop?
Also, 2.0 TFSI coils at 3ms dwell should not misfire even at 750nm. I have not tested more personally.

I hope you get it sorted. 550nm is just not the torque to get misfire issues on this engine, unless something is wrong with ignition system.

[vcosmin]

Ok, because it is weird that you are getting this problem at 550nm.
Both brand new original coils, as well as 2.0TFSI coils can easily handle much more than this.

Have you tried increasing dwell time? Maybe it's too low? Or maybe you have a big voltage drop?
Also, 2.0 TFSI coils at 3ms dwell should not misfire even at 750nm. I have not tested more personally.

I hope you get it sorted. 550nm is just not the torque to get misfire issues on this engine, unless something is wrong with ignition system.

No, i get this problem with the last setup 750nm, and 1.8bar boost @ 5200rpm. Also i use e85, which is much more taxing in ignition system.Dwell was adjusted.

http://www.youtube.com/watch?v=oN6BPOGxZCc - missfires.