Night @ the Dyno!

[Formulaboy95]

Is it just me or does that dyno sheet look choppy? I would have thought the S/C would make it flatter up top. Those #'s should be much higer. Get a data logger on that thing and see what is going on. My #'s with a 75 shot pulsing off/on put down 315 RWHP/379 TQ. Before headers, and before I found out about the knock problem. N/A runs were like 275 HP/ 297 TQ. NX Guarantess w/in 2% of their gains at the wheels. Something was wrong to lose 35 RWHP. The 379 TQ was right on par though.

Get that thing checked out. BTW, is it intercooled?

[fastTa]

Is it just me or does that dyno sheet look choppy? I would have thought the S/C would make it flatter up top. Those #'s should be much higer. Get a data logger on that thing and see what is going on. My #'s with a 75 shot pulsing off/on put down 315 RWHP/379 TQ. Before headers, and before I found out about the knock problem. N/A runs were like 275 HP/ 297 TQ. NX Guarantess w/in 2% of their gains at the wheels. Something was wrong to lose 35 RWHP. The 379 TQ was right on par though.

Get that thing checked out. BTW, is it intercooled?

It is common for most of the dynojet sheets you see to be graphed using a smoothing factor of 5. On a scale of 0-5, 5 is the smoothest. If you notice they used a smoothing factor of 3 on paxton350's graph. Really just a personal preference.

[Nightrage]

How do you know Joe's car is making less than 300 RWHP? I've never seen dyno #s of his T/A I thought 108 mph trap speed would be in excess of 300 RWHP.
By the way, take a look at this thread: http://www.f-body.com/forum/showthread.php?t=10433 302 RWHP and his main mods at the time were CAI, catback, and custom tune.

Wow, i've never seen that. Someone, i think it was Joe, told me that my car probably had 250RWHP right now. I didn't think that the few mods he had would bring it up an extra 50. Now that you mention it, i realize how wrong i am. In comparison to my car he has headers, a better cat-back, the TB bypass, an air foil, less rotational weight so he doesn't have as much parasitic loss as i have, plus i'm sure he has other power making mods. I never knew how much of a difference a custom tuning could make either. I never knew how easy it really is to wake these things up. Wow. Thanks again!

[raroZ28]

Wow, i've never seen that. Someone, i think it was Joe, told me that my car probably had 250RWHP right now. I didn't think that the few mods he had would bring it up an extra 50. Now that you mention it, i realize how wrong i am. In comparison to my car he has headers, a better cat-back, the TB bypass, an air foil, less rotational weight so he doesn't have as much parasitic loss as i have, plus i'm sure he has other power making mods. I never knew how much of a difference a custom tuning could make either. I never knew how easy it really is to wake these things up. Wow. Thanks again!

Joe told you his car only made 250 RWHP?

[Joe 1320]

Joe told you his car only made 250 RWHP?

No, that his car had probably 250 RWHP.

[raroZ28]

No, that his car had probably 250 RWHP.

Ok, I read his sentence 3 times over and I still thought he was saying yours did. My bad

[blackthunder50]

Exactly what do they perform when you get your car dyno'd? Can they tune the car with minor bolt ons and bring it to maximum performance. Or is the PCM tune better. I would really like to look into tuning the car.

[Joe 1320]

How do you know Joe's car is making less than 300 RWHP? I've never seen dyno #s of his T/A I thought 108 mph trap speed would be in excess of 300 RWHP.
By the way, take a look at this thread: http://www.f-body.com/forum/showthread.php?t=10433 302 RWHP and his main mods at the time were CAI, catback, and custom tune.

The times listed in my signature were made without a few mods that are currently on the car. I haven't had the car on a dyno, but I would guess that 300 RWHP is a ballpark estimate. I can't imagine the car going faster than a high 108 mph based on the mods, but with cool air ya never know. I know that I was knocking on 12s with less mods than now so I can't wait to get some new times.

[fastTa]

Exactly what do they perform when you get your car dyno'd? Can they tune the car with minor bolt ons and bring it to maximum performance. Or is the PCM tune better. I would really like to look into tuning the car.

It gives them the oppurtunity to place the powertrain in motion to give them a "realistic" load being placed on the motor. They also will normally measure the air/fuel ratio using a wideband O2 sensor. This allows them to more precisely map the fuel and timing. It also allows them to see in real time how the changes made to the PCM affect the overall power, idle characteristics, a/f ratio, peak power, power under the curve, and part/wide open throttle response.

PCM tuning is essentially just an educated guess. They can normally get pretty close, however dyno tuning lends itself to be a much much better tool.

[paxton350]

youve got to figure if the comp is cutting timin at higher rpms due to the knock module, that is def robbing some h.p and torque... but of how much. its most definately a problem in the ignition circuit, because the air/fuel is right dead on according to the dyno. would a 3 pulse spark help the situation? like an msd box? i only have a blaster coil in there now w/ taylor wires...

[fastTa]

youve got to figure if the comp is cutting timin at higher rpms due to the knock module, that is def robbing some h.p and torque... but of how much. its most definately a problem in the ignition circuit, because the air/fuel is right dead on according to the dyno. would a 3 pulse spark help the situation? like an msd box? i only have a blaster coil in there now w/ taylor wires...

Possibly, but I suspect that is the least of your worries. The first thing I would do is install a quality intake manifold boost sensor/gauge. Then if you are still using your PCV system, make sure your check valve is working properly. And make sure you are not getting belt slippage. I would be willing to bet that you are not getting anywhere near 7 lbs at the manifold and that your crankcase pressure is way too high. High crankcase pressure will also rob horsepower.

[paxton350]

well over the winter i had the blower rebuilt w/ all new seals etc. they also "modified" the impeller giving another 1.5# or so of boost on a 6# pulley, i also installed an oil cooler for the "head unit" as well with an inline pump which increases blower oil capacity as well as helping with the temp of the blower, however i didnt do anything to the pcv system... so fast ta you think i should creat my own pcv bypass valve which empties the crankcase pressure into the in side before the blower? i saw on summit moroso has valve cover "evacuation lines".... could is use something like this as well?

thanks, -chris

[fastTa]

It's best to just ditch the factory PCV valve setup and plug the intake nipple to where the PCV line attaches. The stock PCV system is designed to accept vacuum from the manifold and not boost. So if you did not modify your PCV setup, you are basically blowing the majority of your boost through the PCV valve and consequently into the crankcase.

The efficient way to properly evacuate the crankcase is to run a hose from the inlet side of the blower to one or both valve covers. This needs to be done as airtight as possible, so depending on $$$ braided SS and AN adapters is the way to go, BUT...you can get away with using the stock valvecovers and some vacuum hose. I would suggest placing some type of "catch can" between the blower and the valve cover to prevent any oil from being ingested by the blower.

[Joe 1320]

What fuel are were you using?

[paxton350]

ok, im definately going to do that then fast ta. do they sell plug kits for the pcv system? can i use any 3/8th hose from the valve cover to the inlet side of the blower? also, the granatelli mass air sensor is pretty far before the inlet side of the blower it is seperated by about 2 feet of plumbing, the only way to make an evacuation hose fitting would be to fabricate something for the hose on the inlet plumbing to the blower, BUT the mass air sensor is way before where i could fabricate this fitting... the air filter is a cone attached to the filter then the plumbing to the inlet on the blower, would this increase in air effect my air fuel mix since this crankcase pressure is being added after the mass air meter?

thanks,

-chris