The new truck goes to the tuner tomorrow but I'm very concerned due to the conversation I had with him today.

He warned that the:
- driveshaft can fail
- tires can come off the rims or explode
- supercharger belt can shred
- boost on deceleration can blow the intake off the motor or blow the engine

Engine Specs:
2001 Lq4 stock unrebuilt with 80,000 miles
whipple blower with blow off valve set to stay constantly closed (bypass)
65 lb injectors, removed whipple computer

His statement is that as a tuner on a dyno he is going to redline the motor and get it running as fast as possible.

1) Why did he resist the idea that the dyno be used to dial in the motor at low boost (5 psi) and low rpm where I actually spend all my time driving it? On the street I've never given it more than 50% throttle because after that it just makes more noise but doesnt accel any quicker or it just burns the tires at lower speed.

2) How likely are the above failures to occur and how can they be prevented?

3) Am I wrong for thinking that speed limiting the computer to 98mph and keeping the engine under 4000 rpm is a good idea?

If something breaks minus the belt tomorrow I am completely screwed. This vehicle is my work truck / daily driver and not only can I not afford the downtime but I have no way of paying for a new engine.

What should I tell the tuner? What procedure should we follow for the tune?

The only thing I can think of that I will do tonight is put the whipple blowoff on a switch on the dash so I can release pressure before I release the throttle.

Someone help me sleep tonight because its looking like I'm not going to get any.

 

Just tell him what you want. If he isn't willing to listen then he's not a good tuner or a businessman. Everyone has different preferences, and if he's charging you, he should cater to your needs.

 

Go to another tuner, he sounds like a hack.

 

He's probably using a dynojet or other inertia dyno, which is WORTHLESS for any sort of tuning outside of wide open throttle.
Inertia dynos practically require a 3rd gear pull when making significant power or else you'll rev to redline in just a second or two. Too high of a driveshaft speed can cause it to fail. Similarly, too high of a tire speed can cause it to fail and the supercharger belt issue is just another possible thing that can go wrong. With your bypass valve, you should not have any boost under closed throttle.
When tuning, you should at the very least touch on all RPM points at WOT to ensure that the setup is safely tuned at that point. When all is said and done, if you wanted to keep it to that RPM and speed limit, have at it. Should make plenty of torque to not need to spin very high.

 

dyno runs completed with no trouble. more info later. thanks for the help.

 

I got this picture on this site years ago, thanks to whoever posted it. It shows how to set up your bypass so that it is vacuum activated. So anytime there is vacuum behind your throttle,the bypass is open. Lack of vacuum into boost closes the bypass. I tried to run mine with the bypass closed and it really heated the intake air temperature up during cruise.

 

thanks for the pic, its a little unclear but i will take a look at the truck maybe it will make more sense