VVT tuning with compcams limiter
TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
At 3000rpm(+5) that 20ft/lb gain of torque is quite abit over a cam that was say installed +2 all the way. From your tables it looks like VVT is worthwhile. Once you get it all figured out the final results should be interesting. It would be interesting to know the difference at say 2000rpm which would be around a nice cruise rpm going down the highway. It appears there might be a little gain in mpg with the extra torque available.
Do you have the phaser limiter installed or did you remove/modify it? As pointed out in this thread, you're going to be limited to about 8-10 cam deg variation with the limiter, so I'm not sure why you claim I made "small variances" when the VVT tune is moving it from +6 to -1 in my testing above? I know your cam is smaller than the TSP grinds most of us are working with, but what large variances are you planning?
As for the changes? I want to basically rape the hell out of the VVT tables when it hits the dyno. I'll do one just as is for a baseline as its what seems to work best from seat of the pants. Then i'll do a pull with VVT zero'd completely. Then add sweeping changes to my baseline tune and compare the gains/losses after the fact.
The funny thing is I would have sworn on a case of beer that mine makes the most impact up top, WAY up top. This things seems to carry out RPM so much higher than this little cam "should" which makes sense in my peanut brain that retarded cam makes for higher peak. Anyways I got a new phaser here now Im just waiting on my LS2 damner to arrive ( 5-7 days ufff ) and if im not swamped with work then I should have it back together in a day or so then off to the dyno I go but.... the white stuff has been falling. No salt on the roads yet here but JUST North of me there has been over a foot of snow. If the weather catches me before I get out? It'll be next spring. Blah
I assume you logged these runs. Did you see anything interesting in the data that might explain the above? Also did you confirm the cam timing was remaining static when you locked it at +2 and +4?
TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
"This things seems to carry out RPM so much higher than this little cam "should" which makes sense in my peanut brain that retarded cam makes for higher peak."
That is generally true and I had forgot about that. This VVT thing could be very interesting. I think we all will be waiting for your results.
That is generally true and I had forgot about that. This VVT thing could be very interesting. I think we all will be waiting for your results.
Here's the VVT table (low/med/high baro tables the same) that I ran on the dyno, before locking to +4 and +2 for the last tests. The Actual cam timing tracks the commanded pretty closely, but does go +/- 0.5 cam deg at times.
@3000 rpm I find it interesting that the airflow is only about 2% different between the +2 and +5 timing, but the torque is up by over 5%. I wonder what's going on there. Also look at this:
Here @6300rpm you have a 6% swing in airflow and less than 0.5% change in HP. I wonder what's going on there?
I assume you logged these runs. Did you see anything interesting in the data that might explain the above? Also did you confirm the cam timing was remaining static when you locked it at +2 and +4?
Here @6300rpm you have a 6% swing in airflow and less than 0.5% change in HP. I wonder what's going on there?
I assume you logged these runs. Did you see anything interesting in the data that might explain the above? Also did you confirm the cam timing was remaining static when you locked it at +2 and +4?
There could easily be 3-5% variance in the airflow.
"This things seems to carry out RPM so much higher than this little cam "should" which makes sense in my peanut brain that retarded cam makes for higher peak."
That is generally true and I had forgot about that. This VVT thing could be very interesting. I think we all will be waiting for your results.
That is generally true and I had forgot about that. This VVT thing could be very interesting. I think we all will be waiting for your results.
It's interesting that the TSP VVT-2 and VVT-3 dyno tests both flatlined at 5800rpm, so I'm sure the cam will peak higher, but they must have been running into another limitation which is why I asked about their test mule mods. I'm guessing the stock exhaust ports were limiting them?
TSP VVT-2 2010 Camaro L99/auto dyno
TSP VVT-3 2010 Camaro L99/auto dynoMy heads had a 5-angle job and some exh bowl work done while getting
cleaned up. But I also have smaller (1-3/4") headers, a stock (C6) air intake & filter, and smallish (L92) throttle-body.. All these variables and more will affect peak power numbers from one vehicle to the next.. My numbers could have
been peaking at the rev-limiter as some of them look, or they may have continued an upwards trend and peaked at 6500?? At least comparing my VVT peak HP at 1deg cam retard vs the 2deg cam advance, the VVT-2 cam in my car didn't seem to like the extra cam retard and there might have been a sweeter spot between +2 and -1, or the -1 may have kicked up abover 6300...
Last edited by 85MikeTPI; Nov 27, 2012 at 06:35 PM.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo TECH Junkie
Joined: Dec 2005
Posts: 3,092
Likes: 11
"It's interesting that the TSP VVT-2 and VVT-3 dyno tests both flatlined at 5800rpm, so I'm sure the cam will peak higher, but they must have been running into another limitation which is why I asked about their test mule mods."
I agree. There is something wrong with both those dyno runs. No way that motor should have been peaking at 5750. I believe the VVT-3 cam is something like 231/239 at .050" with the total lift around .615" to .620". Something amiss for sure. I don't know what supporting mods were used with the posted tests.
I agree. There is something wrong with both those dyno runs. No way that motor should have been peaking at 5750. I believe the VVT-3 cam is something like 231/239 at .050" with the total lift around .615" to .620". Something amiss for sure. I don't know what supporting mods were used with the posted tests.
Those cams carry well though they keep it up and dont nose over. Im probably going to be around 430whp or so would be my guess based on my trap speed and smaller grind with a single full 3" exh. Im not really a dyno racer either its just a tuning tool so you can see if your gaining or losing ground
TECH Fanatic
Joined: Jul 2006
Posts: 1,732
Likes: 0
From: K.C.
Attachment 381732
Here's the VVT table (low/med/high baro tables the same) that I ran on the dyno, before locking to +4 and +2 for the last tests. The Actual cam timing tracks the commanded pretty closely, but does go +/- 0.5 cam deg at times.
Here's the VVT table (low/med/high baro tables the same) that I ran on the dyno, before locking to +4 and +2 for the last tests. The Actual cam timing tracks the commanded pretty closely, but does go +/- 0.5 cam deg at times.
Well the entire table was locked at a value of 4 (+2 cam deg advanced) and of 2 ( +4 cam deg advance) since my cam is installed at +6. With the VVT table given above, I basically showed what TQ the cam can do down low by the 0s in the table and what HP the cam can do up top by the 8s (actually max of about 7) and the other +2 and +4 tests show the in-betweens.
I cant search old stuff anymore im zapped and finally wrenching on this thing again. Which cavity is the ideal one for the phaser limiter I cant recall or find the pic? got a link to that thread or pic anyone?
Yeah so did I but I recall a pic in one of the many threads suggesting one cavity was slightly bigger than the rest. Seems to me it was this one I have the arrow pointing too in this pic so thats where I installed it last night.
Yeah the little notch reminded me. I wish I had a phase log of the other cavity though, it would have been neat to compare. Anyways its in there now I "might" get it fired back up tomorrow if I can clear out the day. Lots going on
Yeah Id like to try a different cam too but I have WAY too many projects piling up so this ones done for a few years. It cooks dont get me wrong I like it, but I could handle a hella lot more aggressive cam than this thing.
The pic in the instructions is correct (I think it's the cavity next to the pivot bolt). It's identifiable by looking at the vanes. All of mine didn't actually touch the body of the phaser, except the larger cavity...