Thread: Think I went with too big of a turbo...

It is not safe to rev a VE to 8k on stock cams and springs. With springs it's ok. You will get valve float.

Yeah, the ramp angles on the stock cams seem to provoke float pretty early. 7500rpm is the most I would take it and be wary of bouncing the rev limiter really hard. You have a soft limiter and that will help. I revved my VVL on stock cams NA to 8k daily with no rev limiter. So that is about 7700rpm or so. It worked just fine, but I have heard of valve float happening sooner.

On Sunday I was playing around with the cam switchers again, making sure they were being switched and all and forgot to plug up the yellow wire (cam ground) to the MSD8969.

Drove the car two days beating on it, dataloging it, didn't even notice the power difference. Today I was reving it to around 4k just for kicks and didn't hear the cams switch on for some reason. Well I just noticed that they were unplugged.

Does the higher lobe overlap so badly that I can live without it?

I would say if you don't feel it, don't bother switching it. I ran my car to redline daily for a while because i didn't see the point in having the cams switch. It seemed pointless because i didn't notice any power increase. Sure, it got louder. But you didn't feel a thing. Sometimes when the ex kicked in, you would feel a power LOSS.

when we were using the log manifold we thought was wrong vvl activation points also, tried 4500 then 5000 , damn that car was so lazy with the log its a shame. Changed to Tubular and .86A/R , 15psi with tubular and big housing felt like 22psi with log setup, when we went to 21 psi all hell broke loose , when the VVL activated , it had you pinned to the seat.

Imagine 4WD + 21 PSI @ 8300 RPMS+ 225 Toyo Proxes RA1's in the front, then in a race we tried 120 shot but it Roasted 1st and kinda 2nd , threw out a shim from beating limiter (mayb valve float?) and 3rd gear never went in

wanna see ? go here video removed
wish that 3rd gear went in

No kidding. I'll play around with the VVL switch points, before the low cams wouldn't even hit redline and I would feel a rev limiter like face against the windshield effect.

Now doing two days of runs I was wondering on why it wasn't knocking and on why my TP got to 100 no problem (105ish is 11.5 psi).

Coheed I finally fully read and understood your first post in this thread. My stupid brain always skims and misses the key points.






Yeah definitely know that log is a bit issue here. Ben and I have been talking about possible replacements and it's just either costing too much or would require a complete rebuild in piping. I'm getting to the point of just welding my own manifold together.

Sorry the video violated the no street racing policy and I had to remove it.

Something I just looked at Vadim, I uploaded my AEM tune that I was running and looked at the knock sensor settings and knock input as far as affect on timing. The AEM keeps it really simple. For one I didnt even have the knock input enabled meaning the AEM was doing nothing when it saw knock previously. So for one I enabled it and two the AEM's base setting for it even to start taking away timing is to see 2.7 volts from the knock sensor or more. Anything else is just harmless. Right now i have it set to take away 4.7 deg of timing when it sees above 2.7 volts. It has a refresh rate for timing when it sees no knock of 200 revolutions of the crank before it will add back that 4.7 to wherever in the map its currently at. Great feature that I was not using and that probably could have saved the head the first time around. Second time around there wasnt anything I could do as it would have knocked no matter the timing just for the fact it went really really lean. Like in the 15:1 range lean, when the fuel pressure dropped to 25psi.

Just something to think about when it comes to knock and what is actually detonation and whats not.

Coheed gave me these links in a PM, but I feel like they are important to share to explain why VE's suck with logs and not so good with boost.

The SR20VET Cams




DE cams have 16* of overlap, VE cams have 48* of overlap, and VET cams have 13* of overlap. S4's, which are considered to be great boost cams, have 28* of overlap.

Now for some reason I was thinking 20V cams where the same as VET cams. Because of that I was thinking VET cams where high lift/duration. In reality VET low lobe cam is smaller lift then even the VE cams. Which means it should be a good gas mileage cam for me, which is the reason I went VE in the first place .

OE SR20VE cams
Low lobe INTAKE - .331" LIFT /220º DUR - Low lobe EXHAUST -.260" LIFT / 244º DUR
High lobe INTAKE - .421" LIFT /264º DUR - High lobe EXHAUST -.407" LIFT / 268º DUR
OE SR20VET:
Low lobe INTAKE - .315" LIFT / 212º DUR - Low lobe EXHAUST -.445" LIFT / 244º DUR
High lobe INTAKE - .433" LIFT / 248º DUR - High lobe EXHAUST -.445" LIFT / ---º DUR
Source

Now with 48* of overlap that tells me you better have a good flowing long runner manifold to avoid reversion. Otherwise you are better off with the VET cams. Which is what I'm starting to look for as of right now.

Actual testing of the VET cams by that guy:
Mods III - Slapping in the SR20VET cams

Big thanks to Coheed for explaining the benefits of the VET cams. Another big thanks to BenFenner and Ashton for helping out with random here and there things

VET cams are the way to go if you want to keep your log manifold. Cheaper than redoing most of your setup and you can get to the power goals you want. You will be able to up the boost without having reversion issues causing the pistons to heat up quickly and cause detonation. Cant go wrong. Im telling you Coheed has been there done that. Learn from his example.