Rev limit advice needed

[Schmieder]

Hey, this kind of thing is what these sort of boards are for

If you read Corky Bell's book Maximum boost, you will read that, yes, load levels do go up, but not extreme amounts. I will have to go back and reread that section to find out just how much they go up and get back with you, unless someone else who has read it recently remembers.

I agree, Maximum Boost is a great read. It helped me build my turbo.

My car is proof you can run 8psi on stock springs. I had on rare occasions spiked to 12psi while tuning up the MBC/WG Spring and it wanted to go go GO! I would wind up to 6500 often, but no more. Just because I didn't want to, not sure if my build could do it or not w/o valve float.

The camshaft in my 3100, pretty sure others are the same, is actually really good for turbo. So you have the advantage there already.

I am now a firm believer of "It's all in the Tuning". There are people who push large amounts of boost on stock internals for years w/o a problem. All these people had 1 common advantage, the engine was tuned very well.

Detonation, running lean/rich, etc is where most problems arise from. As an example, I choose Hypereutectic Pistons over Forged. Hypers do not expand much and are great tolerating heat. The only down side is they are brittle when they encounter detonation or peak pressure occurs to soon for what ever reason. But a good tune and a spark knock detection tuned good will keep my hypers happy for a long time.

If your gonna boost, you need to have the ability to tune yourself. Many will say you don't need to but I wouldn't. ANd a good wideband AFR is a must too. But your Narrowband AFR should be replaced to ensure accurate stoich readings...which the WOT depends on concerning fuel trims.

[GM Ontairo]

It's funny you guys mentioned corky bell's book. The first thing I did after I bought the blower was read that. I remember the section you are referring too. It has something to do with when the load builds and releases at the moment the crank is dropping from tdc. I don't think I could explain it and have it make any sense at all but I remember reading it and understanding the concept. So I can see the point you are making and I agree with you.

You also raise a good point about the wideband a/f system. I've got about $70 in this a/f set-up at the moment and it was just sort of an afterthought. The narrowband is just a lightshow at best. My favourite part is when the lights come on like a fan all the way from rich to lean, I'm going huh? I'm focusing on another project right now so the priority just isn't there. The current narrowband might not tell me exactly what base I'm on but at least it'll let me know what ballpark the game is being played in.

On the subject of tuning. I'm carbed with a distributor so tuning is limited. When I hear the word tuning I think laptop and fuel injected. Don't get me wrong there is definitely some things I can do, however I can't really cut fuel out at certain times or richen it at others like a nifty f/i set up can.

As I previously mentioned I like to take this truck out on the road course so it sees anywhere from 2750-5500 rpm for a couple hours at a time. I did turn it up to 5500 from 4500. I'm afraid to push it much more then that for extended periods of time. If I was drag racing I could understand going up more because it would only see peak rpm for a short instant before dropping again. Where as I can hold that peak rpm through a turn for as long as 5+ seconds. Maybe I'm just being a little to leery.

[pocket-rocket]

Being leery will keep the pieces off of the pavement though

[Schmieder]

Carbed, I see. When I said narrowband, I only meant for the pcm to get a true signal. I would go nuts if I had a narrow band gauge. Like watching two fine ladies play tennis in skimpy skirts.

Tuning, yes its laptop and fuel injection. I didn't realize you are carbed. But isn't there weights and springs to tune your carb? Like make it run a little richer at WOT?

I'm not a carb guy......

Being leery will keep the pieces off of the pavement though

Haha, yeah.

The only thing a good mechanic can't fix is the Nut behind the Wheel.

[pocket-rocket]

Weights and springs are for non electronic distributors. Carbs are jets and needle valves, mostly IIRC. He has it easier for tuning when it comes to fine tuning fuel. Large changes to the carb means it comes apart and jets are changed out. When in fine tuning he takes a screwdriver with him to turn the screws (with the needles on the end) one way or the other for fueling adjustments.

On a side note, I've always heard the joke as being the nut loose behind the wheel, lol.