Dyno Tuesday, Predictions?

crzyone · Post by **crzyone** » Sat May 17, 2008 3:34 pm

May 28 @ 2pm.

Will take video and pictures again. I will be happy with 270whp but I would be very happy to get closer to 280 or 290.

befarrer · Post by **befarrer** » Tue May 20, 2008 3:02 pm

Why the hell cant you pick the date on a weekend? Now I cant come and watch.

The Dark Side of Will · Tue May 20, 2008 3:41 pm

crzyone wrote:Those pistons that were not firing were taking up huge power.

How much power do you think it would take to power an air compressor that spins at 6000rpm and puts out 200psi? That is a shit load of parasitic loss on 2 pistons. I bet they were sucking up 25+hp easy.

So, instead of sucking up 25+hp now they will be putting out around 70-75hp. I bet my base run will be 250+whp.

With the throttle open, the pumping losses from those two pistons was virtually nil. Just like in a deactivated cylinder in an engine with DOD, the energy the engine puts into compressing the air on the compression stroke is returned on the power stroke. All the energy consumed is in moving the air from the TB to the tailpipe.

crzyone · Post by **crzyone** » Tue May 20, 2008 8:15 pm

I see what you are saying, more just pumping loss then anything. Depends on how much pressure remains in the cylinder when the exhaust port opens. Still takes more energy to compress the air than you get back from it expanding and pushing on the piston on the way down.

Ben, I can't chose the dates. They are booked through June and are just stuffing me in there to finish off my tune. Would be nice if it was a weekend and wasn't rushed. Still need to find a way to get an RPM signal to the dyno. They read pulses off a sparkplug, I might have to rig my coilpack somehow with spark plug wires on the rear bank just to get some torque numbers....

The Dark Side of Will · Tue May 20, 2008 8:39 pm

crzyone wrote:Still takes more energy to compress the air than you get back from it expanding and pushing on the piston on the way down.

Come again? The intake pulls from 14.7 psi, the exhaust pushes to 14.7 psi. The air actually gains energy in between as it absorbs heat from the engine, so pumping losses will be virtually nothing at WOT. The only difference in pressure comes from differences between intake close ABDC and exhaust open BBDC.

Part throttle is a different matter, because the pistons are trying to pull air against a mostly closed throttle plate... but then so are all the other cylinders in the engine...

whipped · Post by **whipped** » Tue May 20, 2008 11:38 pm

crzyone wrote: They read pulses off a sparkplug, I might have to rig my coilpack somehow with spark plug wires on the rear bank just to get some torque numbers....

Steal the output from the tach wire from the BS 3.

crzyone · Post by **crzyone** » Wed May 21, 2008 12:16 am

I clamped his sensor over every wire I could find going to my dash and nothing was registering. I need to look at the pinout and verify which wire it is.

whipped · Post by **whipped** » Wed May 21, 2008 12:35 am

No you have to ditch the inductive clamp and tie the tach wire directly into the dyno logger. The tach output is like 5 volts, so it won't hurt anything. They should be able to swap the clamp for an alligator clip or probe or something.

The Dark Side of Will · Wed May 21, 2008 7:05 am

Ditto.

Just wire in a Molex connector so they can plug it right in.

Zac88GT1 · Post by **Zac88GT1** » Wed May 21, 2008 3:44 pm

Do they have a pickup blanket that they can lay over the coils? When I dynoed my car they used a little blanket thing that they taped over the coil packs, I dont see why it wouldn't work for coil on plug.

Shaun41178(2) · Post by **Shaun41178(2)** » Wed May 21, 2008 3:56 pm

coil on plug cars are so abundant now a days, the question is what do these dyno shops use to dyno these cars? Thats what they would then need to get to get a tach reading from your car.

Aaron · Post by **Aaron** » Wed May 21, 2008 4:11 pm

Shaun41178(2) wrote:coil on plug cars are so abundant now a days, the question is what do these dyno shops use to dyno these cars? Thats what they would then need to get to get a tach reading from your car.

Seriously, every shop in the world can dyno an LS1. And if they can't, then it isn't a shop you should be going to. Just tell them to dyno it like it's an LS1.

Series8217 · Post by **Series8217** » Wed May 21, 2008 4:12 pm

Aaron wrote:
Shaun41178(2) wrote:coil on plug cars are so abundant now a days, the question is what do these dyno shops use to dyno these cars? Thats what they would then need to get to get a tach reading from your car.
Seriously, every shop in the world can dyno an LS1. And if they can't, then it isn't a shop you should be going to. Just tell them to dyno it like it's an LS1.

No no, an LS1 does not have coil on plug.. it's coil-per cylinder. It still has spark plug wires.

Aaron · Post by **Aaron** » Wed May 21, 2008 4:15 pm

Ohhh, that's their problem, they can't get a plug wire...

Ok, carry on as usual, excuse my lack of teh foniks.

whipped · Post by **whipped** » Wed May 21, 2008 5:26 pm

Zac88GT wrote:Do they have a pickup blanket that they can lay over the coils? When I dynoed my car they used a little blanket thing that they taped over the coil packs, I dont see why it wouldn't work for coil on plug.

Welcome! :thumbleft:

Blue Shift · Post by **Blue Shift** » Wed May 21, 2008 10:10 pm

Do they have the paddle they can set on your decklid? The BAR ref shop used something like that to pick up my ignition system with.

crzyone · Post by **crzyone** » Thu May 22, 2008 1:08 am

I will have to ask them. the guy running the dyno seemed to know his stuff, but he was stumped when trying to find an RPM signal. I will ask if he has one of those coil blankets.

I really want to know my torque curve, want to see how the 2000+ Northstar compares to the earlier engines.

The Dark Side of Will · Thu May 22, 2008 6:29 am

Blue Shift wrote:Do they have the paddle they can set on your decklid? The BAR ref shop used something like that to pick up my ignition system with.

Yeah, but you've got plug wires...

Zac88GT1 · Post by **Zac88GT1** » Thu May 22, 2008 11:24 am

whipped wrote: Welcome! :thumbleft:

Thanks!

crzyone · Post by **crzyone** » Fri May 23, 2008 3:44 pm

AFI Performance wrote:I have never heard of a pick up blanket?? I have both a traditional spark plug wire attachment for rpm pick up, as well as a special coil on plug wire attachment. The problem is not being able to find a wire to hook it to.

For example, on a mustang with COP I hook up to one of the two wires that goes into the coil.

Martin

So, it doesn't look promising. The 2000+ N* is one of the few engines I know of that use this arangement, the other being the Shortstar.