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Greetings folks- hate that my first post is a plea for help. I'm totally new to the tuning aspect and just had a ton of work done to my 2009 corvette Problem is its not making anywhere near the power it should be. Can anyone review the file I downloaded and give it a once over? Thanks-
Best to list your modifications and what power you are making versus what you think it should be making.
Do you have any logs of it?
Brodix BR3 heads, Texas speed stage 4 F35 cam, LSXR 102 Intake, nick williams 103 TB, Corsa CAI, kooks 2" longtubes, kooks 3" offroad Xpipe, Corsa extreme axle back. Stock ignition coils, accel ceramic plug wires, NGK plugs. Dewitts radiator, dual spal fans, 174 lingenfelter thermostat, derale trans cooler...Car had a BTR stage 3 cam in it and made 351/320 on the dyno. Haven't dyno'd it with new cam but the track times (and the feel) are exactly the same.
*edit- Car is a A6 with a 3200 stall
Not that smart on the hptuners just yet, but I can definitely give it a go and run some logs.
Thanks-
Here is a short idle log
Sounds like a low compression issue to me. Big cam do that unless things are done to the engine to bring it back up. Cant say for sure though, not enough information to make that assumption. A good tune can help, but wont fix mechanical issues. No pun intended, I just see this a lot being discussed across forums.
What other information do you need?Quote:
Originally Posted by danmw2003
I dont need any information. The calculations should have been done during the build planning phase of your project, prior to installation. Everything needs to be measured with a degree wheel and your chambers volume to do all the math required to see where your CR is at. If I had to guess your CR is around stock 10.5 ish and probably should be closer to 12.0:1 for that cam. But to get to 12.0:1 CR there's piston to valve clearance issue you have to deal with along with the volume of the aftermarket heads you put on it. A lot of variables there to account for, and no way to really know without measuring and documenting everything. The tune can be perfect, but wont make any compression to bring your power up. Compression is your best friend for NA cars, and should be a focal point during planning. Most people dont do any of this and just slap parts on because of what they read on the internet, and or whatever salesman they talk to, tells them at their chosen speed shop retailer. Again no pun intended, so dont take any of this the wrong way. Just my humble opinion and obviously, just another keyboard warrior here, but I think you'd have much better results with a smaller cam.
All solid points and I respect the honesty. The build was done off of a previous build (same parts) that made very good power. Mine however, not so much. Currently seeking 2nd and 3rd opinions from other builders. Thanks again-Quote:
Originally Posted by danmw2003
BTW, I see you're from metro Detroit, I am originally from Madison Heights.
https://www.corvetteforum.com/forums...m-for-ls3.html
I realize you have more than a stock LS3, but man, bigger heads and 2" primary headers and that cam sounds like something that only starts to think about doing something around 5500 RPM. Might be a decent combo with 100 more cubes...
i quickly reviewed this...opened up your high octane table and saw thisAttachment 114322 who in gods name thought it was a good idea to have the timing fall off of a cliff like this??? the timing table needs to be somewhat of a gradual slope down to the higher airmass cells.
Unless you aren't even getting close to the 1.36g of air in the table.Also you high and low octane tables are the same...not something i would do as the computer has no way of reducing your timing if you experience some knock. This is also a maf only tune (your VVE has been disabled) which from a drivability aspect isn't the greatest idea with an aftermarket cam
Have been thinking long and hard about this as well. Knocking the cam down to the stage 2 range might be where I end up going. Thank you-Quote:
Originally Posted by blindsquirrel
Hmmm, good question (kidding, I know who). I do know the knock sensors have been desensitized as well. Thank you for that info....Quote:
Originally Posted by sgod1100
Having knock sensors desensitized isn't uncommon especially for aftermarket cams. I have mine desensitized on my ctsv with the stock cam because they are very touchy. As long as they aren't completely disabled they will still sense knock. fyi, here is my spark table on my ctsv that i tune myselfQuote:
Originally Posted by jasonb357
Attachment 114326
If you do a WOT run that will tell you how far down the spark table you are going (cyl. airmass) and get a better idea of how the slope should look and where it should go to.Quote:
Originally Posted by jasonb357
Quote:
Originally Posted by sgod1100
Interesting. I will bring this up and see what my tuner says. I'm very green when it comes to this type of tuning, not to HP making, but this tuning. It seems there be a few different issues, mechanically and tuning wise. Thanks again
yyup no problem. let us know what he saysQuote:
Originally Posted by jasonb357
I am the one you emailed the tune to off the forum on FB. It hasnt been brought up here but if your AFR is 12.3 at WOT, the tune pretty much is not gonna fix the problem. Check your cranking compression with injectors unplugged and throttle blade open, then crank it on 7 cylinders with a gauge in it to get an idea of running compression. Run a leak down test just in case compression is getting by, but those heads and cam need to be on a big inch motor. Intake, head, exhaust paths have to be perfect with the correct amount of overlap with a perfect reversion amount which boils down to an engine dyno with multiple parts to swap. I dont know mid lift flow numbers on those heads, but accelaration is gonna be horrible if they dont match. Try restricting your exhaust some how to see what happens. Your exhaust flow effects your intake flow on a LS so much. I do not run headers unless its a Supercharger build. Just no Horsepower there but I do have a device Ive invented to restrict reversion on manifold exhaust. You still gonna have to retune because its gonna throw your AFR off at WOT. I didnt go to school for this, but a did a class in Hard Knocks.
Via PM, I was told it also got .030(!) thicker head gaskets when the new heads went on to avoid valve clearance issues. So it's now under 10:1 static, which is a huge problem given the rest of the combo.
A lot of people have no clue what they're doing. They think forums, YouTube videos and the people they talk to at their chosen speed shop will tell them what they need to do. This is what happens when you think you can do something based off YouTube and forum posts. Slap parts in cuz its cool and then be disappointed when it doesn't run as good as it should. Using a .030" thicker gasket to help PTV clearance was absolutely the wrong thing to do, especially for a NA car. Yeah cuz .080" plus quench area is going to help. Whoever your getting build advice from, stop it.