[laynlo15]

Originally Posted by asthmamax11

This is the exciting part where all the work pays off
It's much more dialed in now with 10x better conditions.
Running 9's on port injection and a set of R2's on the back will be super impressive.

12 more days

Back on the dyno Thursday or Friday for final dial in

[KingLT1]

Originally Posted by laynlo15

I know others have run in the 9s on 20" drag radial but have they run in the 9s with stock Lt1 fuel system. I know I have an aid in the Jms booster but still have the Lt1 HPFP, stock injectors and stock in tank pump. I had a lot of fuel mods on my 16 to run 10.00@139 so maybe we can do it on stock stuff and heavier then stock.

Port Injection is an extensive fuel system mod... Lol

[laynlo15]

Oh, let's get technical would you. It does have additional injectors, but still relies on the stock fuel pumps that came from General Motors in this car when it was new. Gotta love it, between King and Josh its just like a clown show.

[Joshinator99]

Originally Posted by laynlo15

Oh, let's get technical would you. It does have additional injectors, but still relies on the stock fuel pumps that came from General Motors in this car when it was new. Gotta love it, between King and Josh its just like a clown show.

Who, me?!?

[Stefano]

I can’t wait for the results, not an easy task on 20” drag radials, but if anyone can do it, you guys can!

[laynlo15]

Originally Posted by Stefano

I can’t wait for the results, not an easy task on 20” drag radials, but if anyone can do it, you guys can!

Thanks Stefano, its pretty stellar right now compared to the car we had at the Fest. It wants to swap ditches pretty quickly even at a 40 mph roll off with traction control on. Glad I learned to drive in Missouri ice and snow.

[cjperformance]

Do the 10 speeds have the torque limit per gear like the 8 speeds do? Seems like your (Laynlo) car is still able to overpower the tires at launch and cut a good 60ft even with that potentially happening.

Since you reduced the MAF table to fool the DI into thinking theres less airflow (to allow port to make up the addl fuel), maybe the tune is fudging the numbers enough to think its not exceeding the torque limit in those first couple of gears?

In other words your comp thinks you are only making 500 ft/lbs instead of 650 (or whatever it actually is)? Thus not triggering the throttle to close (or at least not as much)?

[laynlo15]

Originally Posted by cjperformance

Do the 10 speeds have the torque limit per gear like the 8 speeds do? Seems like your (Laynlo) car is still able to overpower the tires at launch and cut a good 60ft even with that potentially happening.

Since you reduced the MAF table to fool the DI into thinking theres less airflow (to allow port to make up the addl fuel), maybe the tune is fudging the numbers enough to think its not exceeding the torque limit in those first couple of gears?

In other words your comp thinks you are only making 500 ft/lbs instead of 650 (or whatever it actually is)? Thus not triggering the throttle to close (or at least not as much)?

Well I must say that watching Mike take over my computer and work on the tune for the Reflex controller and get it to communicate with the ECU and the HPT is beyond my pay grade. Watching him scale all the tables and bring in the PI and drop the DI is very cool and then fire it up and go for a drive and feel the difference in the seat of the pants and realize how such small changes can make sure a huge difference in performance is very cool. I wouldn't know how to do any tuning at all if it wasn't for Mike, he tuned my 16 SS to it best 9.41@147 and I kept an eye on everything he was doing and allowed me to make changes when needed for weather changes, track prep etc. All this PI is so new to me I'm still just watching and learning if that's possible at almost 71 years old. Its impressive for sure.

[laynlo15]

If it was earlier in the year I'd purchase a Hoosier RC Components Drag Pack and run the current set up at the track and then swap to the drag pack to see what the difference would be. I've been looking at the weight differences again as I did with my 16 SS when I originally switched back in 2016. Its just about 100 lbs and that's basically what I added with the blower and accessories including coolant, that would put me back down close to 3800 and some change depending on how much fuel is in the car. I'm absolutely sure I could run in the 9.90s with a drag pack with bias ply skinnies and slicks. I'd do it but don't want to spend 2000 bucks now when I have a new trailer being built that's going to be here this week.

[KingLT1]

Originally Posted by laynlo15

Oh, let's get technical would you. It does have additional injectors, but still relies on the stock fuel pumps that came from General Motors in this car when it was new. Gotta love it, between King and Josh its just like a clown show.

I am pretty sure Brett had a few NA H/C cars that went 9's with no port injection on stock fuel system. If you want to pull enough weight and remove aero it shouldn't be too hard.

Originally Posted by cjperformance

Do the 10 speeds have the torque limit per gear like the 8 speeds do? Seems like your (Laynlo) car is still able to overpower the tires at launch and cut a good 60ft even with that potentially happening.

Since you reduced the MAF table to fool the DI into thinking theres less airflow (to allow port to make up the addl fuel), maybe the tune is fudging the numbers enough to think its not exceeding the torque limit in those first couple of gears?

In other words your comp thinks you are only making 500 ft/lbs instead of 650 (or whatever it actually is)? Thus not triggering the throttle to close (or at least not as much)?

Yes, they do and that could be a possibility. Or there is still enough torque to overpower the tires even with the throttle partially closed.

[laynlo15]

Originally Posted by KingLT1

I am pretty sure Brett had a few NA H/C cars that went 9's with no port injection on stock fuel system. If you want to pull enough weight and remove aero it shouldn't be too hard.
He may have and wouldn't doubt it. He pushes pretty hard but I'm at full weight except the back seat which I did take out to add the Jms wiring to the throttle pedal. I did my own back seat delete which added just a few pounds back off the 28 I saved with it out. I may pull the front seat also but haven't decided yet. I can do that at the track if I need too, just not sure yet as that would save another 58 lbs. Other than that I'm not removing a lot of weight just to say I ran in the 9s.



Yes, they do and that could be a possibility. Or there is still enough torque to overpower the tires even with the throttle partially closed.

I agree with King on this point and he's a way better tuner than me.

[KingLT1]

I am just basing that on the fact when I launch on the street, I am intentionally only 42% throttle until about 30mph and still cut a 1.8 60ft and run 10.50's. So, I could likely limit my throttle in the first couple gears under 4k rpm and could potentially go quicker. With PD superchargers we make all the torque... so throttle limiting can easily go unnoticed since we can barely hook @ 50% throttle. On a well prepped track then removing any throttle limiting will be faster if you can hook. Some play around with engine timing as well to help with traction.

CSP made a video on this 4-5years ago and likely why GM uses this feature more aggressively on the ZL1's. I plan to play around with this feature some to try and help with street traction.

[laynlo15]

Originally Posted by KingLT1

I am just basing that on the fact when I launch on the street, I am intentionally only 42% throttle until about 30mph and still cut a 1.8 60ft and run 10.50's. So, I could likely limit my throttle in the first couple gears under 4k rpm and could potentially go quicker. With PD superchargers we make all the torque... so throttle limiting can easily go unnoticed since we can barely hook @ 50% throttle. On a well prepped track then removing any throttle limiting will be faster if you can hook. Some play around with engine timing as well to help with traction.

CSP made a video on this 4-5years ago and likely why GM uses this feature more aggressively on the ZL1's. I plan to play around with this feature some to try and help with street traction.

So far we've just lowered the timing as it was pretty aggressive. I've seen the table for partially closing the throttle, not sure which is better so I guess we will find out if the timing will take care of it. Right now the forecast calls for really fast conditions of mid 60s and I'm thinking the DA should be between -500 and 500. If I'm correct my 1st time trial should be about between 9 and 930 am so it should be mid 50 and DA will probably be in that Zero and the power should be there.

[asthmamax11]

King
Pratt's cars ran 9's on 20" street tires like Nitto R2s or full drag pack with slicks?

(Sorry had to throw more fuel on this fire)