Picking a New Full Race Stall Speed

[Alky V6]

The software doesn't work real well for a turbo application where the engine power curve can be different in first gear, and the other gears for that matter.
What I've had to do was create a power curve for first gear only that made the software match real world. That file is used for 60' work only.

Another file was created for everything past first gear. This resulted in a 60' with that file that didn't exactly match the file for 60' work only, but the 60's were within hundredths of a second, so for overall accuracy, it was exceptable. I've actually created files that matched real world very well. It took a lot of time working the software and comparing it to several real world cases over the years, but now, especially after separating out the 60' work, I've come up with a couple files that work very well.

The way I'm using the nitrous real world, I had to include the nitrous hit in the main power curves in the software, instead of the feature that adds in the nitrous hit through a separate table into the main power curves.

I have to warn you guys, though. If you have a car that has a different power curve in first gear, and then is different after the shift into a higher gear, you'll pull your hair out trying to get the rpm graph to match real world.
I've put in a lot of time getting the software as close as I have it. I wouldn't want to wish the struggle I went through on anyone.

 

[Alky V6]

Is everyone having fun playing with their new program?

 

[BadAssGN]

Is everyone having fun playing with their new program?

Acess is Very Limited in the free trial. but I can see how it would be helpful

 

[Alky V6]

For those that are trying to calculate my hp, I should add, that performance was on a weekend where the outside temps were 101 F.

 

[cruzn57]

I can atest to that!

For those that are trying to calculate my hp, I should add, that performance was on a weekend where the outside temps were 101 F.

race conditions were lousy, hot dry dusty, in fact the Nos bottle over pressurized, and wouldn't release!
so on launch nos didn't spool the turbo, and the motor was on it own!

 

[Alky V6]

I also didn't take into consideration the extra weight of the new turbo or the temperature of that day at Bakerfield when I calculated the 1130hp figure.

 

[DFISCUS]

Hey Don,

I'm trying out a TC slip calculator. I come up with 9.3358 % slip with your combination with the 76 turbo going through the traps at 7800. If that's right I'd say the slip would be even higher with the added HP of the 91 turbo and the load of the taller tires. Just trying to check the math. If this is true it would seem that not only is the TC too tight on the bottom but it is too loose on the top. I believe that you have already stated this about your TC before.

Dave Fiscus

 

[Alky V6]

Hey Don,

I'm trying out a TC slip calculator. I come up with 9.3358 % slip with your combination with the 76 turbo going through the traps at 7800. If that's right I'd say the slip would be even higher with the added HP of the 91 turbo and the load of the taller tires. Just trying to check the math. If this is true it would seem that not only is the TC too tight on the bottom but it is too loose on the top. I believe that you have already stated this about your TC before.

Dave Fiscus

That sounds about right. The drag sim was showing me 9-10% on the top end depending on settings.

 

[Alky V6]

She's back in the fives!
Best reaction of the night for me and the car: .037 sec.
1.37 60'
3.939 330'
5.997 1/8 ET
121.85 1/8 mph

It was very cold after the sun went down. I had a hard time trying to get the nitrous bottle pressure up where it needed to be. Luckily, even with the low bottle pressure, the hit was clean.
I still have some tweaking of the boost controller pressure curve to do. I over corrected to get the boost low enough to keep the 1-2 from blowing away. Now I have a clean 1-2 shift, but the rise after the shift needs to be controlled better so that it begins to rise sooner after the completion of the shift.
The new TC demanded some very minor tweaking of the fuel map and nitrous timer. By the 3rd pass, we got a pretty clean pass. The new TC allowed me to drop .8 of a second off the nitrous on-time after the transbrake release point.
The amount of nitrous on-time after the transbrake is released is now 1.3 seconds, before transbrake release, .995 of a second.
The new TC is a little tighter than hoped for, and with practically a full second on-the-nitrous before the transbrake is released, launch rpm is reaching 4857rpm/109kPa. Lower than the hoped for 5600rpm/130kPa, but even though, according to spectator reports, the front tire popped up off the ground, 6 to 12 inches, three times throughout the launch on the last pass of the evening.
Wheelie bars were installed for this testing session, since the TC was an unknown factor. I didn't get video, but I believe the car didn't use the wheelie bars on any of the passes.
The impression from the driver's seat was that the car left the line straight, flat and with a hint of the tires popping off the ground. The pull felt very cool.

Something that is very interesting about these latest test session results. I was playing around with different scenarios on the drag sim with this new TC before the testing session, and just happened to try a scenario where the TC might deliver a stall speed, on the nitrous, of 4800 rpm. The sim predicted a 1.35 60'. Very interesting.

 

[Alky V6]

The crickets have been quiet lately. Probably busy eating their words,... again.

A summary of the results up to now.
On the first outing attempt with a new TC, a small amount of preliminary tuning work done to work the TC into the combination, a conservative max boost for the testing session, and a sloppy boost control pressure curve up to this point, for all practical purposes the present combination has now matched the average performance of the prior T76 combination. I wonder how many people thought this time would never come after the change to the 91mm.

Tuning items that still need attention and optimization:

Nitrous shot size for this new TC combination. There is now the opportunity to increase the shot size.

Boost controller control pressure curve. It's close, but needs fine tuning.

Max boost level. After the boost controller is dialed in better, then boost levels will be pushed up to find the new limits of this combination.

Tire pressures. As boost levels are pushed, different tire pressures will be tried.

Chassis settings. As boost levels are pushed, the chassis will be more closely looked at. After the nitrous shot size is finalized, a lot of video taping of the launches is planned.

 

[Dusty Bradford]

The crickets have been quiet lately. Probably busy eating their words,... again.

A summary of the results up to now.
On the first outing attempt with a new TC, a small amount of preliminary tuning work done to work the TC into the combination, a conservative max boost for the testing session, and a sloppy boost control pressure curve up to this point, for all practical purposes the present combination has now matched the average performance of the prior T76 combination. I wonder how many people thought this time would never come after the change to the 91mm.

Tuning items that still need attention and optimization:

Nitrous shot size for this new TC combination. There is now the opportunity to increase the shot size.

Boost controller control pressure curve. It's close, but needs fine tuning.

Max boost level. After the boost controller is dialed in better, then boost levels will be pushed up to find the new limits of this combination.

Tire pressures. As boost levels are pushed, different tire pressures will be tried.

Chassis settings. As boost levels are pushed, the chassis will be more closely looked at. After the nitrous shot size is finalized, a lot of video taping of the launches is planned.

Uhmm. The people said you need a looser converter.............you finally made the change and it went faster.

 

[Otto J]

The crickets have been quiet lately. Probably busy eating their words,... again.

LOL, Eating what words???
that you have a 91mm turbo that takes a 400 shot or nitrous to spool and FINALLY (how many months or years later)runs as fast as your 76 did,How much boost is the 91 running at?

Ill give ya a little pat on the back for FINALLY changing your convertor.
Now if you keep taking the rest of the advice of the pros here you may end up running in the 8s a in a few more years

 

[baadgn]

The crickets have been quiet lately. Probably busy eating their words,... again.

Don, The crickets are not the only ones that have been quiet, your followers have also said NOTHING!!!! I will give you a hint as to why that is the performance to date with your combo is unimpressive. When people see a 3560# stock block car, with a 70 mm turbo run 5.80s at 125 mph in the 1/8. And here you are BRAGGING about your accomplishments, I think we are all a little stunned at your arrogance. To give you an idea how far off you truly are I will use Chris Lyons car as an example. He has a 270 ci motor, champion heads, 88 turbo, 3350# and NO NITROUS!! He runs 5.20s at 138 mph in the 1/8. Thats over 7 tenths and 16 mph faster in a car that has no nitrous assist, smaller turbo and weighs more than yours. I know you have a smaller motor but your nitrous assist makes up for that shortcoming. Yes, you have old school m&a heads but you do have a bigger turbo and a lighter car so its a wash. We told you the turbo was to big and the converter was too tight and you changed the converter and the car picked up and now your wondering why everyone is quite. Let me provide some insight, we the crickets KNEW the car would pick up if you changed the converter as we have been wasting are breath telling you that for years/months. As far as your followers they have seen and understand what we "the crickets" have been trying to tell you all along. You finally listened and the car picks up so I think they are starting to see the picture. Just so I and the rest of the Buick community understands your "cricket" statement. What your doing is bragging to us that the car picked up because you changed a part that we have been telling you to change for years/months. Would this be an accurate assesment of the situation? Don, the "crickets" are done with you. You ask for our help and then fight us every step of the way, challenge our knowledge then in the end make the changes we mentioned and then insult us with this "cricket" statement.

 

[Otto J]

THough they do not have nitrous and don't run methanol, there are plenty of guys that have run 1.2* 60 fts on drag radials/slicks only 28" tall running 3.50 OR LESS gear that can be up on launch boost in under 2-3 seconds,completely pro tree raceable with no extra sources or methods to aid spoolup short of proper tuning while running convertors capable of 170+ MPH at 7600 RPM.

I realize that you are trying to build your own custom anti-lag system but it really appears your the only one with a lag problem

 

[lazaris]

Don, The crickets are not the only ones that have been quiet, your followers have also said NOTHING!!!! I will give you a hint as to why that is the performance to date with your combo is unimpressive. When people see a 3560# stock block car, with a 70 mm turbo run 5.80s at 125 mph in the 1/8. And here you are BRAGGING about your accomplishments, I think we are all a little stunned at your arrogance. To give you an idea how far off you truly are I will use Chris Lyons car as an example. He has a 270 ci motor, champion heads, 88 turbo, 3350# and NO NITROUS!! He runs 5.20s at 138 mph in the 1/8. Thats over 7 tenths and 16 mph faster in a car that has no nitrous assist, smaller turbo and weighs more than yours. I know you have a smaller motor but your nitrous assist makes up for that shortcoming. Yes, you have old school m&a heads but you do have a bigger turbo and a lighter car so its a wash. We told you the turbo was to big and the converter was too tight and you changed the converter and the car picked up and now your wondering why everyone is quite. Let me provide some insight, we the crickets KNEW the car would pick up if you changed the converter as we have been wasting are breath telling you that for years/months. As far as your followers they have seen and understand what we "the crickets" have been trying to tell you all along. You finally listened and the car picks up so I think they are starting to see the picture. Just so I and the rest of the Buick community understands your "cricket" statement. What your doing is bragging to us that the car picked up because you changed a part that we have been telling you to change for years/months. Would this be an accurate assesment of the situation? Don, the "crickets" are done with you. You ask for our help and then fight us every step of the way, challenge our knowledge then in the end make the changes we mentioned and then insult us with this "cricket" statement.

Couldnt have said it better. I found that remark was in poor taste especially when many people tried to assist in your project and gave excellent advise which proved to be correct.

 

[S2V6RACER]

Don, did you end up putting a PTC in the car or just a pump change?

 

[HighPSI]

Based on the way you calculate hp. Did the car pick up or lose hp now that your incrementals have changed? I know we can make that pass with under 800 rwhp.

 

[BadAssGN]

I'm Glad to hear the Convertor change helped out.

Keep getting Faster Donnie

 

[Alky V6]

LOL I figured that would wake you guys up. You know I like waking up in the morning to a healthy dose of beatings. Where have you been?

The small motor is coming up (more tuning still to do, guys) on big motor performance with a combination where every detail, except the hs TC now, goes against the grain of everyones thinking or opinion, and you all can only muster a 'told you so'?
When I was doing 1.28s with the small motor and tight TC, where was the 'told you so'?
And if the TC change had resulted in a flop, which I never claimed was a possibility, what would you be saying? Told you so? 'It's your combination. It won't work. You have to do it the way we do.' And who's being arrogant?

I've explained this before, but some just don't seem to understand. Sticking with the tight TC for so long taught me a lot about the fuel map. Given the chance to explore the fuel map, I just refused to pass that opportunity up. That's just how I am. Sorry if that disappoints many of you. I can honestly say that there are only a few small spots in my fuel map that have not been completely optimized. That could not have been done with a high stall torque converter!

Thanks for all the help, guys. Some of you have been real supportive.

 

[Alky V6]

Based on the way you calculate hp. Did the car pick up or lose hp now that your incrementals have changed? I know we can make that pass with under 800 rwhp.

Keep in mind that this was a simple t&t outing. Not a max to the wall, finalized tuneup, optimized chassis, find the absolute max for the configuration run.

The hp is definitely down. The latest testing was done with much less average boost throughout the run than I've ever done for any configuration. I haven't attempted to push the boost yet. I'm still working on the launch.

The time lapse that the car was on a plateau of any sort of respectable boost was 2.36 seconds on the final clean run of the session. And even in that time period, the boost level was stepped. Even I won't attempt to try to figure out the hp for that kind of a pass.

I'll post up the datalog trace for that pass when I get the chance.