Dyno 3/23 Noon @ Synapse?

[JClark]

I agree with the whole "you made what you made" idea (read the other thread, kept mouth shut ), just curious on how different dynos produce different numbers and if its percentage based, or, say, a flat amount difference. As in, one dyno reads 11% higher than another, or it reads 25whp higher than another, regardless.

Curve was nearly identical before on all the different dynos. Small variances, but overall very similar. Here's the new ones from today:







Your thoughts?

Peak pressure was 6.4psi, when it's "supposed" to be 7. I dont know if I need to spin it higher (went right up to the new software's limiter...), or if I'm just leaking .6psi somewhere? I realize .6psi is a very small leak.

The dip in power up top is right when the ECU dumps crazy fuel. "Safe" I would say.

[Shawn96VR-4]

A few thoughts:

1) .5PSI or any PSI is quite a bit of air flow at your displacement
2) Why is the boost only 3PSI at like ~4,800? I am not sure the plumbing on your IC system but could you have some leaks?
3) 12-13+ AFR on 93 octane is way too lean for me. Are you tuning it yourself or relying on the stock ECU to handle that? One of the issues with my friend nick who did a 3000GT NA -> TT (Now T) was that the NA ecu would JACK the timing through the roof and the AFR was not right (It didn't compensate for the boost)

Dyno Dynamics - Great for tuning; Can hold just about any RPM and I believe WOT backwards; Some people quote 13% lower #s; Load is dead-on
Dyna Pack - Very user configurable; From that, you can really skew the #s high or low. I have read both. Very good for space; I am a bit ify about measuring at the hub... Sounds like it wouldn't be as accurate as the rollers... I am not too versed though. In your case, sounds like it was middle of the road.
Dyno Jet - Easy to bring cars on and off; Built-in so you need the space; Some people claim bigger #s but it depends on the software installed. The one I go on reads lower than the 'typical' dynojet and the owner won't change it because the #s match the track; Some people claim the load is a bit off resulting in much lower AFRs. As soon as you hit the street, AFRs swing back up.

I have spoken to Morgan about his dyno practices and they are very good. He makes a run and checks plugs and makes a run and checks plugs. He does it very methodical and makes small changes and moves on. I have heard a lot of bad shit about people hot lapping the cars and just cranking the boost w/o regard. When I dyno, *I* am making the tuning changes and slowly turning the boost up and making changes. We make a run while Ray stares at the AFR/TIMING and power curve during the run to possibly abort if something doesn't look right. I make a change and we try it again. When we get close to pump/race gas limits, we let the car cool 10 min and make a clean run.

I am going back at the end of the run. I still have not tuned the car except for street tune as I kept maxing out the fuel system. It's a lot of fun isn't it?

[JClark]

Leak is certainly possible. I'll recheck everything next time I'm in there, but who knows if I can find something that small. For boost @ given rpm, it's just a mechanical increase in blower speed, so the slope of the curve stays the same. Not sure what you meant.

I've gotten a handful of educated opinions on the AFR curve and so far everyone says its perfectly safe for this motor. That was the first thing I asked Morgan too. The tune is chip-based.

It's been "fun" so far, but I'm hoping there's no tuning involved so I can enjoy my fun. You guys that are constantly tuning your setups have far more patience than I do. I dont have the self-control for that. I just want it to run right, every time, so I can enjoy the car.

On that note, it needs to warm up so we can all get out driving again.

[Shawn96VR-4]

Originally Posted by JClark

Leak is certainly possible. I'll recheck everything next time I'm in there, but who knows if I can find something that small. For boost @ given rpm, it's just a mechanical increase in blower speed, so the slope of the curve stays the same. Not sure what you meant.

I've gotten a handful of educated opinions on the AFR curve and so far everyone says its perfectly safe for this motor. That was the first thing I asked Morgan too. The tune is chip-based.

I am not too familiar with superchargers vs turbochargers but with it being driven off the crank, I expected the boost to be at it's peak well before 5K RPMS. Is that a normal boost curve minus the drop off?

Yea, you might want to find a way to pressurize the intake track. Leaks kill FI cars.

Morgan said that AFR was ok? I guess if there is no knock or drop off on the dyno and the EGTs align, it's ok. I run much more boost so I really run it rich on the backend to hold off detonation. Overall, how does the car feel? That's a big power pickup.

[JClark]

Centri s/c boost is just a linear climb. Pressure increases directly with blower speed, so max boost is at max rpm. Next time I'm in there, I'll start hunting for possible leaks.

Morgan and others have said the AFR is ok. It's not being strained at 13 and dips into 12 when it starts to build more power, which they said is just right. It's no where near knocking and the the dyno suggests it's running fine with it. When the motor was NA and super tweaked out, my AFR touched 14.3 at points and never knocked once even on 91 @ Watkins.

Car feels great overall. 1st and 2nd gear are useless now, but usually I only need 3rd+. Looking forward to warm weather so I can try it with some grip.

[Shawn96VR-4]

Originally Posted by JClark

Centri s/c boost is just a linear climb. Pressure increases directly with blower speed, so max boost is at max rpm. Next time I'm in there, I'll start hunting for possible leaks.

Morgan and others have said the AFR is ok. It's not being strained at 13 and dips into 12 when it starts to build more power, which they said is just right. It's no where near knocking and the the dyno suggests it's running fine with it. When the motor was NA and super tweaked out, my AFR touched 14.3 at points and never knocked once even on 91 @ Watkins.

Car feels great overall. 1st and 2nd gear are useless now, but usually I only need 3rd+. Looking forward to warm weather so I can try it with some grip.

Nice. AFR is going to be leaner for a NA motor. Things get a bit different when you go FI. But, it's slowly going richer as the boost pressure increases. If all other things check out and the dyno curve looks good, then roll with it. When I maxed out my fuel pump, Cossey and I watched the AFR go from LOW 11 to 13 AFR and the TQ just took a dump.

Do I get a ride?

[Celtic1982citleC]

you have great looking curves

[xceebeex]

Originally Posted by MYIX8UR8

you have great looking curves

Keep those thoughts to yourself


Thats pretty impressive power your are putting down for that car though.

[JClark]

Originally Posted by Shawn96VR-4

Nice. AFR is going to be leaner for a NA motor. Things get a bit different when you go FI. But, it's slowly going richer as the boost pressure increases. If all other things check out and the dyno curve looks good, then roll with it. When I maxed out my fuel pump, Cossey and I watched the AFR go from LOW 11 to 13 AFR and the TQ just took a dump.

Do I get a ride?

Yep, the NA stat was just for poops and giggles, I know boost needs a richer mixture. At what boost level did your FP max out at? What are you currently at anyway?

Originally Posted by MYIX8UR8

you have great looking curves

Tee hee. I've got to call Adam today.

Originally Posted by xceebeex

Keep those thoughts to yourself

Thats pretty impressive power your are putting down for that car though.

Thanks mang. I'm waiting on Stage 2 mostly for charge cooling and not the added power, but it should make another 40hp or so.

[Shawn96VR-4]

Originally Posted by JClark

Yep, the NA stat was just for poops and giggles, I know boost needs a richer mixture. At what boost level did your FP max out at? What are you currently at anyway?

Supra FP rewired at ~12V with 43PSI base FP maxed out at ~530AWHP @ 20.5PSI
Supra FP rewired at ~14V (I added BAP but used shitty thin ass wiring) with 43PSI base FP maxed out at ~580AWHP @ 24PSI

Cossey was with me. It really sucked. We didn't tune at all because of this. We just ran out of fuel early on. We added +50% correction to keep the injectors wide open (major bandaid) but the AFR would swing to MID 13 AFR and the TQ would plummet.

I did a rewire to keep the stock voltage at idle because I thought it would overflow the FPR. It screwed me on WOT because it would lag on the boost transition giving me an untunable lean condition (before the fuel pressure would kick in due to the voltage).

I removed the rewire and ran a 6 gauge wire directly off the battery through a 35AMP fuse and using a relay have 13V at all times to the Supra FP. I used 6-8 gauge wire on the Kenne Bell Boost-A-Pump and run ~19V WOT now. I have went ~2.3BAR without fuel cut but the fuel pressure does drop off a tad but the AFR holds steady. I am approaching the limit of that setup. The methanol kit will take care of that tho.

[Captain Moai]

Half a psi isn't enough to bitch about. That may be just a variance in the gauge calibration, flexing inherent in the tubing, pulley variance, etc. You're right where you should be, imo. Peak numbers will vary based on the dyno, but since you dynoed previously, this makes a good comparison to your NA power level. Keep in mind the percentage improvement and the shape of the curve. Note the comparison:

Bone Stock M3 with Intake:


Supercharged M3 @ 6.5psi with other mods:

[Shawn96VR-4]

^^^^
Good post.

Yea, it could be calibration of the gauge. If you can FIND the boost, then use it.

[Captain Moai]

imo, 6.5PSI is below the noise floor. If the kit's rated for 7 and he's making 6.5, then he's doing alright. There will be variances in almost