Twin 66mm L92 6.0 first dyno pull 624RWHP @ 9psi
 

Well...........

First WOT pulls happened today. Sorry for the phone video, but it is better than nothing.
The last pull went only to 5,900 rpm at a little over 9psi.
It was breaking up over 5,500 because it is still too rich.
The targeted AFR is a safe 7.4 for e85 for now and with only 16deg of timing, the car still made 624 RWHP at 4.9 AFR !!! WAY RICH !!!
We will keep leaning out the tune to get a clean pull to 6,800 before upping the boost.
I will hold the power to 750max for now to keep it together till spring.

Jim

*low quality phone video replaced with the actual 737hp pull !!!

__________________

Awesome car. Its guna scream when you sort out those issues and crank up the boost.

Thanks!
I am not 100% sure how far to up the boost due to all the L92 horror stories recently.
I think I will be happy with a 10psi (est 750~ish) tune for now.
This will let me get it to the track in spring and sort out the car and add more power over time.
I don't want to lift the heads on the dyno....

Even with all the horror stories if you have good parts and a spot on tune I wouldn't worry but yea 750 rwhp would be a good number. So is it a street/strip car?

Yep.
The intentions are 60% strip / 40% street but that may change.
The converter flashes to 4,200+ on the dyno at WOT thanks to the turbos coming on so well. But, it drives VERY nice just cruising around so I am happy.
It should be a riot with the transbrake and the 2-step at the track.
I can't wait....

Yea well It should tear some unsuspecting people up on the street.
Have fun and good luck.

Thanks!

What is target air fuel on e85

I wanna see what it can do with more timing at that boost.

We are targeting 7.4 right now. Some racers are running leaner than 8.0 but I want to keep it real safe with the stock L92 heads.
Also, I tested the fuel yesterday and it was actually closer to e-80 since they are mixing the "winter" blend now.

Me too!
This pull picked up 60 RWHP from the previous pull just leaning it out 5% and it is still pegging the dyno's wideband rich! (4.9 AFR !!!)
I have a LM1 in the car which is calibrated to output actual afr to HPtuners for tuning and it has a larger range than the dynojet.
I am guessing that leaning the fuel out to the desired 7.4 AFR and spinning the motor to 6,800 will net over 700 RWHP at 9psi.
A couple more psi should start pushing the "Safe" limit of the stock thin deck L92's.
I will wind up swapping the heads for some o-ringed aftermarket castings but this will be a good setup for now to shake down the car.
It's not like it will be slow as it is.:cool:

I dont know if it would help making things easier to read but you could start doing everything in Lambda. Everythings pretty much universal then. 1.0 for stoich and .72-.74 under boost. Maybe could go richer. Ive heard e85 likes being a little on the rich side since its along the same lines as alcohol. Not sure if you ever look around at other forums but supraforums.com have alot of guys running e85 now with a ton of useful info to read through.

Thanks.
I discussed that option with the tuner.
He is comfortable with viewing the logs in AFR and fully understands the lambda value since that is what he built his PID formulas off of.
I guess it is a personal preference thing. If AFR works for him so it works for me!
A little on the rich side is fine for me, I don't want to hurt it on the dyno before I even get a chance to drive it under boost!

Sneaking up on the tune.
The car made 709hp / 675tq last night and is still rich at just a tick over 11psi.
It ran low on fuel the last run and went a little lean and the run was aborted.
At 5,200rpm it was making just over 700hp already, which shows that there is still some power on the table from leaning it out a little more.
We will bump the boost a little today and tweak the fuel and call it good till spring.
This is still with only 18deg of timing.

Very nice. I think twins are the way to go on a v8. Since they dont need a high PR to make power, you can use 2 smaller turbos and stay in the effeciecy range of the compressor map alot better. Around what rpm are you getting 11psi? Ive thought about doing twin 67mm when i start my build.

It is at full boost around 4,500rpm, which is right after the converter flashes. Perfect!
Transbrake launches under boost should be no problem.
I think I am just getting into the happy spot of the turbos now, because the last 1/2psi change netted over 60rwhp!

I know with E-85 you can run a little more aggressive on the tune, But 11 psi @ 18* of timing @ 7.4.1 E-85 A/F which should be closer to an equivalent of 12.2 Dont you think you are pretty much at your "Safe" Limits?

If your familier with plotting on a compressor map, this site is really nice. With your Twin 66mm's you should be able to get a solid 1000+whp from them when you really get into turning the boost up.

http://www.squirrelpf.com/turbocalc/index.php

The timing hes able to run is gonna be dictated by boost, compression ratio, fuel, and effeciency of the heads. E85 can handle alot of timing without any knock. Alot of Supra guys say they can keep adding timing untill the power falls off and still not have any knock. Saying 18* timing is enough for his setup is too generic. What CR is the engine? If its 9.5:1 then 18* would maybe be enough. But if its 9:1 then it could handle over 20*, and even more timing if its even lower compression. Even just knowing CR isnt enough to say what timing is good enough. Timing should be done on a load bearing dyno and increase it till peak tq is hit without detonation.

The "e85" is actually closer to 80% ethanol this time of year, so I think we are still ok.


Thanks, that is an awesome site. I just wish I knew more about how to use the calculator. I seems as though I might be running to the left of the surge line at lower boost. I'm thinking that 1000whp can happen, but I don't trust the stock thin deck L92 heads.


The engine is 8.9CR

Thanks for the input guys !!!
I am learning quite a bit about the whole tuning process this week.

Just got the call, final numbers (for now) 727whp @ 6,200 and 700ft.lb. @ 12psi