My truck is at shop having a new custom tune written for it because the first tune somehow was showing incorrect air to fuel ratio numbers by the tuner that had it running lean which burnt two valves in less than 200 miles. Got motor repaired and sent it to different shop to be tuned again. BTW new shop figured out tune was running way lean. They got base tune on her and said she was running great. Dyno showed everything was like it should be. Slowly hot her up to 4500 rpms when intake gasket let go. Tuner said gasket was probably installed incorrectly for high boost motors. Do they make intake gaskets that are a lot better than stock ones? He said they have tricks when installing them that keeps them from blowing out under high boost. After adding additional idler pulley to blower setup, belt slip is now not a problem. Anyone else have a gasket to let go like that. With old setup and previous tune, it only could make 10 lbs of boost at 5000 rpms. New tuner had 12 lbs at 4500 rpms before gasket let go. The only good thing about this situation is that old tune hit maxx horsepower of 437 at 5000 rpms. New tuner was at 450 hp at 4500 rpms before gasket let go. We can go to 6000 rpms before rev limiter will kick in. Can't wait to see what she pulls after correct intake gasket is installed. Engine builder said she would scream if we could find a way to give her the boost she craves. Hopefully someone can finally get it running like it should be.

 

Gonna ask tuner what he thinks caused gasket to let go when he gets intake off. Hopefully just a bad gasket.

 

Ive never heard of intake gasket problems. My guess is when they removed the heads they reused the old gaskets to save money (on their end) and they were no good from that point on. Sounds like they also dont know what they are doing. Do you have a wideband? That should tell you if your truck is lean.

 

I wouldn't be surprised if gasket was reinstalled by first shop. They were recommended by a friend so can't blame anyone but him. I should have done my research before taking it to them. Truck has wideband guage and was showing incorrect numbers according to new tuner. Don't ask me how that could happen and how he came up with that, cause its way over my head. He said previous tune was running lean and that's what burnt the valves. I am neither a mechanic nor a tuner so I can only go by what I am told by people who are supposed to know these things.

 

Just got off phone with tuner himself. Info was being relayed to me through who I was on the phone with. He said it wasn't the actual gasket between head and intake. It's leaking between the upper and lower piece. He said they would add a sealer to it before putting the two pieces back together to eliminate any chance of future leaking.

 

Burnt valve could come from high temps too. Boost increases cylinder head temps and you can burn exhaust valves while not running lean.

 

Very true.

 

You had a test done once when your plugs burnt up a while back and the blower crapped itself that had your ethanol level around 18% right? That would cause a lean condition that the wideband a/f can't see. And of course neither can the trucks O2 sensors. And as Irons1n said Egt's rise and that melts valves too. These are two reasons I encourage people to install egt gauges. You can learn a lot about whats happening and not happening with one. They trump a wideband A/F all day long.

 

Not exactly sure what ethenol percentage was when valves burnt, but it could have been as high as 18% which is totally unacceptable to run in our trucks. I will run the EGT gushed by my tuner while he has it in the shop. You and him do agree that aftermarket wideband A/F gauges seen that much help. He even said mine was 1 point off from what his dyno was reading. So when gauge said 11.1 dyno showed 12.1. Using multiple 02 sensors verified this. What brand EGT gauges are you using and are they what you would recommend? BTW I found a guy pretty close to me that sells ETHENOL FREE GAS. Yeah it cost more, but it will be far cheaper than what that other crap cost me. Thanks I appreciate the help.

 

UPDATE. Truck is finally done and at home where it belongs. Couldn't be happier with the new custom tune on it. It runs so smooth, its like driving a different truck. Ed at RB3 Motorsports in Manassas VA did the tunes on it. Anyone in the area looking for custom tunes should definately look them up.

 

Cool. What were your numbers and how much boost?

 

Good news fella.

Lets hear those WHP numbers?

Best thing I did was roll it.

 

I was actually so excited after taking a test drive that I didn't even ask. I was just listening to him talk about what all he did to it to get it running that way. He said it has what he called a driving tune on it. It does drive very nice and still has plenty of power. He did say that he would put a drag tune on it later down the road if I wanted one. He did give me a computer disc with a bunch of stuff on it, but I got to borrow cousins laptop to see what's on there.

 

Finally got disc from tuner to show something on computer. It's a bunch of numbers and not the usual dyno chart. From what I can tell, it looks like it only goes up to 4900 rpms. Looks like like last pull was 400 rwhp. I reckon that's not too bad considering he did say it was a driving tune. I know the motor will turn a heck of lot higher than that, as the rev limiter was set at 6000 rpms when I was running the P1SC. I guess he didn't feel the need to go any higher with the rpms on this tune. I can't complain too much because it does drive like a dream. I will have to call and get him to explain what he meant by putting a race tune on it when I wanted one.

 

Thanks for the info. No tranny recal as I have the 5 spd manual. I still think the D1SC should be able to push more than 13 lbs of boost though. Am I correct on this, or am I at the limit of what it can push. The blower pulley size is 3.00 right now. Not sure how fast it is spinning. It was pushing around 14 lbs with this setup on the P1SC if I remember correctly. I would really like to see 500 rwhp with this motor. I hope I didn't pay 9 grand for a motor that can't produce good horsepower numbers.