I finally got my car on the dyno today. Please take a look.
11-26-2010, 09:24 PM
#1
I finally got my car on the dyno today. Please take a look. For those that have been following my Lag issue, I finally got to get the car on a dyno and work some issues out.
Here is the build:408, L92 heads with SSvalves and mild port work, LS3 intake, VTC-3 cam installed at 105 ICL, 80#injectors, 10.25:1compression, 92mm Fast TB, SD tune, Meth injection, 4L80E with T-Brake, Circle D 4C 245mm billet convertor, Moser 9" with 3.70 gears, Rear Mounted GT-88 with a PT t-4 .98 turbine housing.
We removed the cold air piping from the TB and I pulled the waistgate completly off effectivly making the car NA. We played with lots of things trying to get the 408 to make power. All our runs were made with the convertor locked. The tuner worked all day on this with me bugging him. I got on the dyno at 9am and loaded the car at 6pm. He worked all of my startup and idle issues out. I had that stuff flat screwed up.
As for the injector boundry stuff, we tried the numbers you posted, and we added 10 more percent. We then went back to the stock numbers and made several pulls pulling 10 percent from each. They did help a little but not more then 40# of torque or hp.
The 408, NA, with every tuning trick in the book made a big wopping 338rwtq at 4790rpm and 334rwhp at 5693rpm. With out a dought there is something not right with the engine. I do not think it is in the tune. My next step is to retard the timing back 6 or 12 degrees and try again.
Now for the good news, still with the convertor locked we slowly added boost until we got to 17psi. Here the wimpy 408 made 817rwtq at 5330rpm and 844rwhp at 5555rpm. Not bad, realy nice actualy.
So if I can figure out what the heck is going on NA and get the 408 to make torque in the 500 range and hp in the 450-500 range, I really think we should see 1000+rwtq and 1000+rwhp, and the lag should be almost gone.
If anyone has any other ideas as to what might be going on with the crappy NA numbers, please jump in and throw them at me. I am almost out of ideas.
Here is the build:408, L92 heads with SSvalves and mild port work, LS3 intake, VTC-3 cam installed at 105 ICL, 80#injectors, 10.25:1compression, 92mm Fast TB, SD tune, Meth injection, 4L80E with T-Brake, Circle D 4C 245mm billet convertor, Moser 9" with 3.70 gears, Rear Mounted GT-88 with a PT t-4 .98 turbine housing.
We removed the cold air piping from the TB and I pulled the waistgate completly off effectivly making the car NA. We played with lots of things trying to get the 408 to make power. All our runs were made with the convertor locked. The tuner worked all day on this with me bugging him. I got on the dyno at 9am and loaded the car at 6pm. He worked all of my startup and idle issues out. I had that stuff flat screwed up.
As for the injector boundry stuff, we tried the numbers you posted, and we added 10 more percent. We then went back to the stock numbers and made several pulls pulling 10 percent from each. They did help a little but not more then 40# of torque or hp.
The 408, NA, with every tuning trick in the book made a big wopping 338rwtq at 4790rpm and 334rwhp at 5693rpm. With out a dought there is something not right with the engine. I do not think it is in the tune. My next step is to retard the timing back 6 or 12 degrees and try again.
Now for the good news, still with the convertor locked we slowly added boost until we got to 17psi. Here the wimpy 408 made 817rwtq at 5330rpm and 844rwhp at 5555rpm. Not bad, realy nice actualy.
So if I can figure out what the heck is going on NA and get the 408 to make torque in the 500 range and hp in the 450-500 range, I really think we should see 1000+rwtq and 1000+rwhp, and the lag should be almost gone.
If anyone has any other ideas as to what might be going on with the crappy NA numbers, please jump in and throw them at me. I am almost out of ideas.
11-26-2010, 09:41 PM
#4
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wow, thats a wierd predicament for sure. Im glad you got some of the issues resolved and put down some good numbers!! Soo my take on the issue is...
Untill you unbolt the exhaust system from the collectors and run open headers on a dyno in true N/A form, you really cant base that 338whp off of anything to accurately. Yes pulling the WG will create no boost and run the engine at atmospheric levels, BUT it has to still push all those exhaust gasses through the piping and through the turbo. Basically bottle necking the exhaust flow undoubtedly, which will hinder NA results. Especially on a bigger CI engine.
Untill you unbolt the exhaust system from the collectors and run open headers on a dyno in true N/A form, you really cant base that 338whp off of anything to accurately. Yes pulling the WG will create no boost and run the engine at atmospheric levels, BUT it has to still push all those exhaust gasses through the piping and through the turbo. Basically bottle necking the exhaust flow undoubtedly, which will hinder NA results. Especially on a bigger CI engine.
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11-27-2010, 01:13 AM
#8
The cam is a VTC-3 23?/23? .60?/.60? 116 +6 and it is installed another +6 degrees to bring the power down low, so the ICL is 105. Retarding the cam back 6 degrees wold put the ICL at 111 which is the intended installed settings.
Last edited by Texas_WS6; 11-27-2010 at 03:21 PM.
11-27-2010, 02:07 AM
#9
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sounds to me like restrictive exhaust is why it don't make big na power. You running stock manifolds on the setup? My buddies z28 did the same thing. It made 390hp with a cam only ls1, then we did a rearmount with stock mani's. it lost 100hp if we took off the cold side pipes and ran na, even with the n/a tune. After running turbo for a while, he went back to longtubes and nitrous. it picked the 100hp back up again.
seems like big ci and free flowing parts coupled with stock manifolds are a choke point unless you have boost making up for it
seems like big ci and free flowing parts coupled with stock manifolds are a choke point unless you have boost making up for it
11-27-2010, 02:18 AM
#10
Sounds about right to me. Like everyone else said #s are gonna be low cause of the exhaust setup you have on your 408. That with a 4l80e not gonna make big peak #s. Been watching your problems for a while and it looks like its came a long way.
Good luck on working out the rest of the bugs.
Good luck on working out the rest of the bugs.
11-27-2010, 01:08 PM
#12
Take the +6 advance out of the cam, that will gain you HP because your torque will be moved higher in the RPM band.
Your torque peak is most likely where you reached full boost so you still aren't spooling that turbo until 5300 rpms since you said the converter was locked (great way to kill the lockup clutch btw).
What kind of dyno was this done on? If it didn't have a load cell (like a dynojet 248C) then chances are it will spool quite a bit faster in a real world scenario.
Don't worry about the NA power too much. Without a turbo my car is an absolute turd and probably makes around 250 rwhp based on how it felt when I've driven it that way. A 408 through stock manifolds will be even worse.
The power does seem a bit low for 17psi to me based on your combo, but it's also peaking quite early. I bet with the cam advance you added in removed it would peak closer to 6000 rpms and gain you another 30 rwhp NA.
Your torque peak is most likely where you reached full boost so you still aren't spooling that turbo until 5300 rpms since you said the converter was locked (great way to kill the lockup clutch btw).
What kind of dyno was this done on? If it didn't have a load cell (like a dynojet 248C) then chances are it will spool quite a bit faster in a real world scenario.
Don't worry about the NA power too much. Without a turbo my car is an absolute turd and probably makes around 250 rwhp based on how it felt when I've driven it that way. A 408 through stock manifolds will be even worse.
The power does seem a bit low for 17psi to me based on your combo, but it's also peaking quite early. I bet with the cam advance you added in removed it would peak closer to 6000 rpms and gain you another 30 rwhp NA.
11-27-2010, 01:39 PM
#13
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One vote for cam, retard the cam or maybe go with a different cam that has proven results in a similiar combo. Your powers in the ballpark for 5500rpm, if the power carried to 6200-6700 I think you'll be happy.
11-27-2010, 02:12 PM
#14
I know what you mean with the convertor clutch. Chris at Circle D told me this convertor would hold 1500hp with the clutch locked. Looking at everything on the dyno, the convertor clutch in his convertors are very freaking good, it never showed any slippage.
Yes, the boost still lags to 5300rpm. It starts to build boost at about 4000rpm and full boost is reached at about 5300rpm. Looking at the dyno charts, max trq NA is at 4790 at 338, but the trq is over 300 from 3500rpm to 5800rpm, so the trq curve is really extreamly flat (NA). I would have thought with the cam advanced as much as it is the peak torque (NA) would have been around 3500rpm and up in the 500# range.
Even with the stock exhaust manifolds, I have no Cats, and no muffler, just a 2.5" "Y" pipe gping into a 3" "I" pipe, the waistgate removed opens a 60mm hole in front of the turbo, and the GT-88 turbine housing is a hug thing in itself.
Now in my mind, A tuned only LS3 on this same dyno makes on average 410rwhp and 450+rwtq, going threw the stock manifolds, cats, and mufflers. I am running the same heads (slightly ported), larger CI, better cam, same intake, same if not better everywere, and it makes way way less NA. WTF! I can not help but to think that it should make no less then a stock tuned only LS3.
The dyno is a Dynapack Dyno. Pretty sweet dyno really. It has loading, which the tuner used to fix my idle, and pretty much all the maps. That is why we took the turbo loose, and made individual boost level runs. That way we hit every possible point on the maps. For those that have not been on one of these dynos, they drive wheels are removed from the car and the dyno is bolted directly to the drive axle.
Getting the enigne to make the power it should NA should help reduce the lag, help cut the 60' times down before boost, help to widen the power range, and help increes the peak power.
Next time I decide to build a 11grand paper weight, I am just going to by a junk yard 6.0, put a cam in it, throw 20psi to it, and save my 10,500 for the next 6.0 junk yard engine.
Yes, the boost still lags to 5300rpm. It starts to build boost at about 4000rpm and full boost is reached at about 5300rpm. Looking at the dyno charts, max trq NA is at 4790 at 338, but the trq is over 300 from 3500rpm to 5800rpm, so the trq curve is really extreamly flat (NA). I would have thought with the cam advanced as much as it is the peak torque (NA) would have been around 3500rpm and up in the 500# range.
Even with the stock exhaust manifolds, I have no Cats, and no muffler, just a 2.5" "Y" pipe gping into a 3" "I" pipe, the waistgate removed opens a 60mm hole in front of the turbo, and the GT-88 turbine housing is a hug thing in itself.
Now in my mind, A tuned only LS3 on this same dyno makes on average 410rwhp and 450+rwtq, going threw the stock manifolds, cats, and mufflers. I am running the same heads (slightly ported), larger CI, better cam, same intake, same if not better everywere, and it makes way way less NA. WTF! I can not help but to think that it should make no less then a stock tuned only LS3.
The dyno is a Dynapack Dyno. Pretty sweet dyno really. It has loading, which the tuner used to fix my idle, and pretty much all the maps. That is why we took the turbo loose, and made individual boost level runs. That way we hit every possible point on the maps. For those that have not been on one of these dynos, they drive wheels are removed from the car and the dyno is bolted directly to the drive axle.
Getting the enigne to make the power it should NA should help reduce the lag, help cut the 60' times down before boost, help to widen the power range, and help increes the peak power.
Next time I decide to build a 11grand paper weight, I am just going to by a junk yard 6.0, put a cam in it, throw 20psi to it, and save my 10,500 for the next 6.0 junk yard engine.
11-27-2010, 03:01 PM
#17
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i agree. i cannot wait to see the final numbers on this setup man!
on another note, just because im curious, i thought you were gonna build a truck manifold setup??
on another note, just because im curious, i thought you were gonna build a truck manifold setup??
11-27-2010, 03:18 PM
#18
The truck manifold setup is next. I want to work the issue out that I am having with the 408 right now. All of this was a DIY thing so I started with the rear mount just to see if I could in fact do it. I should have worked all the buggs out of the 408 first. Really it should of had no bugs in it. But it has never made the power it was supposed to make. Talking about the exhaust, when first installed the 408 had Hoocker LT Headers, Single plane intake, no cat, and the cam was a 230/240 .600/.600 114 installed +6. It never made the power either, that what hurried the turbo install. I should have found the problem then. Live and learn I guess.
So once I find the issue with the current setup and prove the number, I will begin moving everything up front. I think I will not do the truck manifolds though. I really do like the front mount turbo headers Virgina Speed is making. I am thinking very hard about ordering a hot side kit from Shawn after Christmas. Either way the turbo is going up front after Christmas. I want the lag gone and my ground clearence back.
So once I find the issue with the current setup and prove the number, I will begin moving everything up front. I think I will not do the truck manifolds though. I really do like the front mount turbo headers Virgina Speed is making. I am thinking very hard about ordering a hot side kit from Shawn after Christmas. Either way the turbo is going up front after Christmas. I want the lag gone and my ground clearence back.
11-27-2010, 03:43 PM
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Piece of advice, when possible only change one thing at a time. that way you know what did what and if it gets worse then its relativley simple to undo it. change too many things at the same time and you could cause new problems, but you wont necessarily know it, or know why or how.
Id start with the cam timing, dont put it all the way back, maybe halfway. its a start, if it improves and you want more then go all the way. jsut dont change anything else lol
Id start with the cam timing, dont put it all the way back, maybe halfway. its a start, if it improves and you want more then go all the way. jsut dont change anything else lol
