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Finally got the vette on the dyno and I have a few questions.
First off…
2011 Corvette Grand Sport M6
Cam motion titan 3 cam (specs in pic)
Kooks 1 7/8 catless longtubes
Intake/TB ported and rod modded by BLP
Haltech air intake
ATI 10% UDP
Glanzer flex fuel kit
LSA injectors
NGK TR5GP spark plugs
Car made 448whp and 436tq on 91 octane.
Current issues
- Tuner said it was knocking and suggested a 160* thermostat. Coolant temp was 224. No fans and 57 degrees outside.
- HP graph was completely flat after 5k rpms.
- At times, idle is very sputtery. Is there a solution to this? It chops real nice but it goes into this sputtering that sounds horrible. Sorry hard to explain.
- Car dies on warm starts .. I can hold the accelerator a tad and it’ll start right up.
Any ideas or suggestions would greatly be appreciated. Will be going back to finish off the 91 and e85 tune soon.
Your tuner has more tuning to do. I would swap plugs to a 6 heat range. The plug you have is too hot for the power you "should" be making. I use AC Delco 41-104 plugs at similar power levels. A 160* thermostat won't help much. Tuning the fans to 100% at a lower temp can help. You need to make sure your radiator and a/c condenser are pristine before going back to the dyno. Also check air inlet for dirty filter and any other obstruction.
Last edited by old motorhead; Jan 9, 2022 at 06:47 AM.
Your tuner has more tuning to do. I would swap plugs to a 6 heat range. The plug you have is too hot for the power you "should" be making. I use AC Delco 41-104 plugs at similar power levels. A 160* thermostat won't help much. Tuning the fans to 100% at a lower temp can help. You need to make sure your radiator and a/c condenser are pristine before going back to the dyno. Also check air inlet for dirty filter and any other obstruction.
Thank you, already ordered some NGK TR6s. 👍 I cleaned the radiator nicely during the cam swap.
I know the first 3 pulls were done without any fan blowing at the car. The IATs were up there. Not sure if the haltech intake has any part in that but It was pretty cold out.
You've still got something going on up top. No way your setup should flat line at 5400 rpm. I'd look real hard at your valve train. Maybe push rod length? Also, with the flex fuel kit, you may not have enough fuel pump if you're still using the stock one.
Yeah, something's not quite right up top. Looks like timing is being pulled or maybe even some misfires. And could should be able to go to 7000 rpm with that cam.
BTR 7.40 hardened pushrods and BTR dual valve springs.
Did you measure to make sure the 7.40 pushrods were the length you needed? Usually larger cams than stock will have a smaller base circle which can usually mean you will need a longer push rod.
For example, in my 2006 I used to have with the LS2, I did a cam swap with a Cam Motion cam and I had to got with a 7.425 pushrod versus the stock 7.4.
If your pushrods are too short, that could be what is going on. But the only way to know for sure is to use a pushrod length checker and measure it.
Did you measure to make sure the 7.40 pushrods were the length you needed? Usually larger cams than stock will have a smaller base circle which can usually mean you will need a longer push rod.
For example, in my 2006 I used to have with the LS2, I did a cam swap with a Cam Motion cam and I had to got with a 7.425 pushrod versus the stock 7.4.
If your pushrods are too short, that could be what is going on. But the only way to know for sure is to use a pushrod length checker and measure it.
Sorry the springs and pushrods are from cam motion too. No I didn’t measure that’s just what they recommend me.
The car runs fine now so I suspect the oil in the MAF was the issue. The tuner did mention the MAF was acting funny during the dynotune.
Blows that I didn’t realize the MAF was dirty until after the tune. 😩
Sorry the springs and pushrods are from cam motion too. No I didn’t measure that’s just what they recommend me.
The car runs fine now so I suspect the oil in the MAF was the issue. The tuner did mention the MAF was acting funny during the dynotune.
Blows that I didn’t realize the MAF was dirty until after the tune. 😩
Most shops recommend 7.40 but this is just plain dumb. Only way to know what you actually need is to measure. And if you don't want your cam to eat a lobe or failed lifters, and you want good valve train stability, you MUST measure.
Sorry the springs and pushrods are from cam motion too. No I didn’t measure that’s just what they recommend me.
The car runs fine now so I suspect the oil in the MAF was the issue. The tuner did mention the MAF was acting funny during the dynotune.
Blows that I didn’t realize the MAF was dirty until after the tune. 😩
well yea that could very well be the issue sounds good to go now so go retune it then re dyno it and see where its at id guess 480-490rwhp at least with your combo
Yep now I just need to figure out how to stop it. I believe the oil is coming from the dry sump vent hose that connects into the air intake coupler. 🤔
Any ideas??
The air filter was cleaned and oiled but I was pretty careful oiling it and It sat on the shelf for 2 months before going on the car. 🤷♂️ Maybe air filter oil?
Dyno time
