Dyno Tune

[mossbergman]

I wouldn't know. Typically around 3500+ But at this point having them is better than having the deletes with improper tuning. The dyno operator did mention to me that with my stall and gearing there wouldn't be any problem with deleting them in the future.

ya thats the truth. i think there is some higher rpm power to be had with a set of deletes on your setup. you also need to update your sig

 

[KStromberg]

Good numbers. If you have an aftermarket high stall converter with a single disc you are not supposed to have it lock up at WOT at all or it won't last very long. Only a triple disc you can lock up at WOT which will help for maximum performance.

Thanks.

Well, actually it does sir and it has been locking up WOT for a long time.

Currently, the lockup occurs in 2nd gear pretty much right away and then in 3rd at ~90mph.

So did they remove the torque management?

Yes. I told him to and he agreed. We don't need no management.

So me NA vs. you spraying a shot? :shifty:

 

[DLF]

so when do they have your imrcs opening?

I wouldn't know. Typically around 3500+ But at this point having them is better than having the deletes with improper tuning. The dyno operator did mention to me that with my stall and gearing there wouldn't be any problem with deleting them in the future.

The stock opening point for the IMRC's on a Gen 2 is 3002 RPM.

 

[DLF]

so where does your extra 25-30 hp come from? are you just a master tuner?

Yes.

He has IMRC deletes, canton oil pan w/windage tray, underdrive pullies, and better A/F ratios. And that's just off the top of my head. Datalogging has been a strong point for him.

And an Accufab TB, 90mm LMAF, and Bosch Gen III 30 lb injectors.

However, I'm still running with converters.

 

[Don Pfau]

I'm not I guess absolutely certain about what's best into 3rd gear for lock-up at this point as far as the track but it was noticeably faster when we delayed it to 87mph and then when I finally suggested 90 mph. I am certain that the car is much slower with lockup immediately into 3rd at 80 mph.

Mine locks up in third gear at over 90 mph and I believe it would work even better set higher to shift rpm's using it like a fourth gear

 

[Lownslowlsc]

Ding Ding Ding!

I will have a WOT video soon. The car put down 268rwhp at 98 degrees fahrenheit Less than optimum conditions and the car wasn't spun on the rollers completely cooled down. On a better day maybe 275

There was a spike on the torque but we're guesstimating around 265. Both shifts complete at 6900 rpms and the torque converter lock-up was delayed until about 90 mph. It was originally set to lock up at 80 mph and I could just feel the bog that I have been feeling for so long with this car on the mail-order tune. Now it pulls A LOT harder into 3rd gear.

Stay tuned. It just got nastier....

What do I win? Make it something good.

 

[KStromberg]

Mine locks up in third gear at over 90 mph and I believe it would work even better set higher to shift rpm's using it like a fourth gear

If you watch Mike Schultz's videos, his converter locks in 3rd gear way up there. I want to say like 105mph. I believe he was messing with those parameters when he was at SSHS11, because you can clearly see the difference in the later runs on that video. He tried locking it up earlier and from what I recall the car performed best with a delayed lock-up into 3rd. And BTW, this was NOT my reasoning at all for delaying my lockup either. (Read "copycat") What prompted me to have it delayed was how the car behaved on the street when I did some test runs. Converter lockup on the dyno is one thing, but I think in real world street driving after the fact things can be way different as in my case.

What do I win? Make it something good.

The satisfaction of knowing that you guessed right.

 

[driller]

Shifting at 7K means you drop to around 3800 rpms on the 1-2 shift and 4500 rpms on the 2-3 shift. 2nd gear gives you more torque multiplication than 3rd gear and makes up for the lower rpms after the shift much quicker than 3rd. With the exception of the initial hit, there is almost zero torque multiplication from 3rd. With a delayed lockup in third, the converter is slipping (a lot) and that means the engine will accelerate faster but that does not necessarily mean the car is accelerating faster.

The best shift point is defined in drag racing as the least loss of acceleration after the shift. Since acceleration is a product of torque and rpm, you can calculate the acceleration from the dyno plot in rough intervals to arrive upon the optimum shift point - realizing these values are with the converter locked.

The wild card is the torque converter lockup delay. With the torque output assumed flat, the best acceleration is obviously with higher rpms. The trade off to get higher rpms is the delay in lockup. If you delay it too much however, the overall acceleration will be lower since the total acceleration is the sum of the unlocked and locked acceleration (remember the tortoise and the hare story?).

Furthermore, each converter will have a different output unlocked than locked and it will vary with rpms. To 'copycat' one setup to another is not going to guarantee the same results.

Long story short... only by comparing ETs at the track with different set points can you optimize the settings. You may think the car is faster with a higher shift point and a more delayed lockup but your ET may actually be slower. Likewise, you may feel the car is 'hitting the wall' with an earlier lockup but your ET may actually be quicker.

 

[Don Pfau]

Understood but my power band isn't as flat as a N/A engine. Its more like a turbo in that boost builds higher with the rpm's.

 

[driller]

Understood but my power band isn't as flat as a N/A engine. Its more like a turbo in that boost builds higher with the rpm's.

Very true, with the centrifugal supercharger, boost builds with rpms and so does torque. The same principles apply, however the torque curve is much different resulting in much faster acceleration throughout each gear. Generally, the valve train will be the determining limit to the power potential.

 

[DLF]

Shifting at 7K means you drop to around 3800 rpms on the 1-2 shift and 4500 rpms on the 2-3 shift.

It's more like 4800 and 5000 in my car, due to the TC.

 

[racecougar]

shifting at 7k means you drop to around 3800 rpms on the 1-2 shift and 4500 rpms on the 2-3 shift. 2nd gear gives you more torque multiplication than 3rd gear and makes up for the lower rpms after the shift much quicker than 3rd. With the exception of the initial hit, there is almost zero torque multiplication from 3rd. With a delayed lockup in third, the converter is slipping (a lot) and that means the engine will accelerate faster but that does not necessarily mean the car is accelerating faster.

The best shift point is defined in drag racing as the least loss of acceleration after the shift. Since acceleration is a product of torque and rpm, you can calculate the acceleration from the dyno plot in rough intervals to arrive upon the optimum shift point - realizing these values are with the converter locked.

The wild card is the torque converter lockup delay. With the torque output assumed flat, the best acceleration is obviously with higher rpms. The trade off to get higher rpms is the delay in lockup. If you delay it too much however, the overall acceleration will be lower since the total acceleration is the sum of the unlocked and locked acceleration (remember the tortoise and the hare story?).

Furthermore, each converter will have a different output unlocked than locked and it will vary with rpms. To 'copycat' one setup to another is not going to guarantee the same results.

Long story short... Only by comparing ets at the track with different set points can you optimize the settings. You may think the car is faster with a higher shift point and a more delayed lockup but your et may actually be slower. Likewise, you may feel the car is 'hitting the wall' with an earlier lockup but your et may actually be quicker.

:iconcur:

If you're able to datalog the vehicle acceleration rate at the track, dialing in the shift and lockup schedules is a snap. While it may sound like the engine is "bogging", earlier lockup usually translates into a better E.T.

 

[KStromberg]

Somebody look at my graph again. That spike followed by a warble on the graph was when a strap slipped on the dyno. The tq/hp are both spiked to get those numbers so my average is more likely to be 255rwhp. I think I'm not happy now. I should have noticed this earlier.

 

[Don Pfau]

Even if you eliminate the spike it is easily 260.

 

[KStromberg]

I can't remember if he let out of it or not at that point when it happened, I was just like oh :q:q:q:q. Maybe the car still would have climbed a bit more on the curve if that hadn't happened?

 

[DLF]

It's more likely that the spike is your TC locking (it happened on both runs). But I agree that your HP and TQ numbers aren't really as high as you thought they were. I just didn't want to rain on your parade earlier. Looks like HP~260 and TQ~255 to me.

p.s. And if you look at the graph, you'll see that your TC is actually locking up sooner on the last run than it did on the first, which in my book at least, is a good thing.

 

[KStromberg]

p.s. And if you look at the graph, you'll see that your TC is actually locking up sooner on the last run than it did on the first, which in my book at least, is a good thing.

3rd gear lock-up is delayed to 90mph. What you are seeing is before changes were made in those parameters after driving the car and the car almost falling asleep when it hit 80 mph.

 

[chris2523]

enough talk already. hit the track!

 

[KStromberg]

enough talk already. hit the track!

It's too hot!

 

[driller]

It's too hot!

Oh, I see how you are now...

Take it to the track anyways and get the DA to convert it back to sea level.

 

[Don Pfau]

Its been at or over 100 deg here for over 3 weeks. Its bothers me more than the car.

 

[98LSC32V]

Take it to the track, it runs what it runs. I've noticed my GTO's IAT/Coolant temps have more of an effect on the car than weather conditions.

 

[KStromberg]

Take it to the track, it runs what it runs. I've noticed my GTO's IAT/Coolant temps have more of an effect on the car than weather conditions.

And I've noticed that my car heat soaks quick no matter what. Warmer temperatures will just hasten that process. Remember I have a stock thermostat also and no cooling fan mods. And while we're on topic, NO SLICKS. It aint going anywhere on street tires.

 

[mossbergman]

And I've noticed that my car heat soaks quick no matter what. Warmer temperatures will just hasten that process. Remember I have a stock thermostat also and no cooling fan mods. And while we're on topic, NO SLICKS. It aint going anywhere on street tires.

Take it to a burnout contest

 

[KStromberg]

Take it to a burnout contest

With my luck and breakage that has happened on this car, I'll pass. I'm pushing the envelope as it is with the valvetrain at this point. I already did my rolling burnout today leaving a stop light. Rolling burnouts are more impressive anyways. Look at my signature. Both of those vehicles will do burnouts. Only one of them does it from a roll.