Big problem with my power dyno numbers

[camcojb]

Originally Posted by TOM NELSON

340 to the ground is probally about 460 hp.I would check a couple of things one do you have 9 pounds in the manifold at your peak rpm serpentines will slip and if it does the car will feel soft as hell.Two with 9 psi even on a 8.5 to 1 350 with the hot cam you should be making at the very least 580 hp crank and you would definately feel that.I'm not sure if you said your transmission but if it's a auto are you sure it's not sliping,just a thought.Run a compression check on all cylinders see if there within 10 percent of each other and at least 110 pounds cranking.If you have that than i doubt it's in the motor.I've had problems with the procharger units I actually have not used your blower before though but in the past there smaller blowers just did not cut it.I had a 383 with a blower i believe was similar to yours lay down 310 to the ground.We changed pulleys you name it.Not big improvements .Switched to a ysi vortech it picked up 400 hp.and made 710 to the ground and the cam was much smaller than your hot cam.I had good luck with there bigger units like the f2's but even there above 10 psi they really start making heat fast.Ignition Timing can be a huge deal on a 8.5 to 1 motor I've seen 100hp from 25 to 35 degrees the low compression engines like timing at 9 psi and only 6000 rpm But beware carbs timing and boost is a scary deal.If it was mine and i felt good about the tuner i would not shy away from 35degrees total timing at 9si and 6000 rpm this can literally transform the engine.Again beware creap up on it.I would for ****s put some 110 in it and put total at 35 dgrees and see what happens given afr's are in the high 11's low 12's.Hope you fiqure it out

Tom, with his BTM he's only got about 15 degrees of timing at WOT and full boost. I think this is a huge power killer, and gave the dyno guy a couple other things to try. Bottom line, he's got to get more timing in the thing, if that takes water injection or whatever.

Jody

[mazspeed]

Originally Posted by camcojb

Tom, with his BTM he's only got about 15 degrees of timing at WOT and full boost. I think this is a huge power killer, and gave the dyno guy a couple other things to try. Bottom line, he's got to get more timing in the thing, if that takes water injection or whatever.

Jody

Hey Jody, do you think with better cooler airflow, would allow for higher timing settings?

[camcojb]

Originally Posted by mazspeed

Hey Jody, do you think with better cooler airflow, would allow for higher timing settings?

absolutely. Cooler air (through intercooling, water-alcohol injection, and to a degree a cold air intake) will all allow more timing and/or boost.

Jody

[mazspeed]

Originally Posted by camcojb

absolutely. Cooler air (through intercooling, water-alcohol injection, and to a degree a cold air intake) will all allow more timing and/or boost.

Jody

Ok second question, would more airflow allow for more timing even if it's the same temp?

[Blown353]

15 degrees is VERY low timing. I would keep bumping it up and keep a close eye on the power numbers and the plugs. I'd be willing to bet it will run best somewhere between 24 and 30 degrees under boost on 91 octane. You're probably leaving 75-100hp on the table running only 15 degrees of timing under boost.

What heatrange plugs are you running? Keep an eye on that too as you bump up the timing. If your heads use 3/4 reach gasketed plugs I'd say you will probably end up with something equivalent to an NGK BKR6ES, that should be about right for that compression and 9 psi of boost. Maybe even one step hotter at 5ES, but start with the colder ones.

With my blowthrough carb setup on 91 octane I was running the distributor locked at 36 degrees, plus another 14 degrees possible with vacuum advance. The BTM box pulled it down to 27 degrees at 15 psi of boost. That's with 15 psi of boost, no intercooler, 9.25:1 compression, and water injection.

Another thing, don't trust the knob on the BTM. Start the engine and run it and use a hand pump with an accurate gauge to apply pressure to the BTM at your maximum boost level, then adjust the knob to your desired timing number while watching the pointer with a timing light. Obviously, do this with your vacuum advance disconnected and at a high enough RPM so the distributor is "all in" if you have the centrifugal advance hooked up. The numbers on the knob aren't really that accurate. In the ballpark, yes, but not exact. I did this on my BTM and made new tick marks on the knob every 0.5 degrees per PSI of *actual* retard as verified by the hand pump and timing light.

[mazspeed]

Originally Posted by Blown353

15 degrees is VERY low timing. I would keep bumping it up and keep a close eye on the power numbers and the plugs. I'd be willing to bet it will run best somewhere between 24 and 30 degrees under boost on 91 octane. You're probably leaving 75-100hp on the table running only 15 degrees of timing under boost.

What heatrange plugs are you running? Keep an eye on that too as you bump up the timing.

With my blowthrough carb setup on 91 octane I was running the distributor locked at 36 degrees, plus another 14 degrees possible with vacuum advance. The BTM box pulled it down to 27 degrees at 15 psi of boost. That's with 15 psi of boost, no intercooler, 9.25:1 compression, and water injection.

Another thing, don't trust the knob on the BTM. Start the engine and run it and use a hand pump with an accurate gauge to apply pressure to it to the BTM simulate your maximum boost, then adjust the knob to your desired timing number while watching the pointer with a timing light. The numbers on the knob aren't really that accurate. In the ballpark, yes, but not exact.

I agree with the knob, but I do have fast burn heads. Do you think that the fast burn heads require less timing under boost? I heard that they do under N/A.

[JamesJ]

You have gotten 76 replys in 28 hours, that says people care. It was said before i bet some members would love to come to your house this weekend and help you with it. the only problem is they may not leave!

[Ummgawa]

Mike

You have guys here that are in magazines every month. Guys that hang out with the Big Dogs in our hobby. You have heard from a good amount of those here. Listen to them. All I can offer is this: Park it in a cool dry spot and let it sit until this passes. There are a lot of us with high 5 figures in a car that we have not even heard run yet. You are so far past the majority of us. Hang in there man, take some offers of help, or cover it and sit it in the corner. Trust me, if you sell, the guy that gets the deal will go that extra inch you need right now and have a wicked killer ride THAT YOU BUILT!

[68protouring454]

take members help, obviously c.a.r.s did not do anyhomework setting the motor up, as any guys i talk to say the ati hats suck, you'll get it, i would just talk to them about the situation, you did not build it to have these issues, goodluck its probably still pissed at you for doing those donuts near traffic!!

[kp.touring]

Well I've been quite, but here I go. In re-but to no doing our home work were do you get off with that. People are throw theirr 2 cents in and those ideas were look at from the start. What we have here is a packaging problem, there is no room for a taller hat over the carb. We know the hat is not helping power, also a single plan intake would work better and ducting the air inlet to get air from outside the car would be awesome, but now we are back to packaging. The other thing is Ca's crap gas we may have 91 oct but it doesn't have the btu's that other areas have so yes our numbers are not going to be those high earth shaking numbers.
Bottom line is Mike's car does have more in it, given time to tune and add some way to cool the air inlet charge it will get there as this was the car's first tuning on the Super Flow dyno. And just a note with anymore timing the engine started to pre-ignite, so we are looking strongly at water injection.
Wish we had room for a intercooler.
Kevin
C.A.R.