[RHD ZL1]

Originally Posted by 2023_ZL1-AUTO

Sounds like you understand great how your car is working. I have data logs that go from stock lower to a 9.45" lower, I can look at the boost and try to see the differential between the two, it might give you some kind of usable data.

I'm sure it's the tune each of our cars have, but, when I hit the beam at the end of the quarter mile I'm only in 5th gear. My TCM is tuned, and it auto shifts aggressively for the drag strip. So, it might be that mine holds a few gears longer at higher RPM (It shifts in some gears at +7100rpm.

If I can ask, what is your 1/4 ET, MPH and 60ft time? I'd be curious to compare to mine as I too have all stock internals.

Take care!

If you could look at your logs and let me know what the boost gain was from stock lower to 9.45 that would be great. I know that each car is a little different however at least I would have some kind of usable data like you mentioned. Thank you.

As others have mentioned, I personally wouldn’t be shifting the OEM Valve Springs and AFM Lifters to 7100+ rpm.

Sure, I ran 9.85 @ 139.85 with a 1.38 60ft.

Here is a discussion to what the car ran prior to fitting the 9.17 lower…… https://www.camaro6.com/forums/showt...=631571&page=2

Here is a vid of the pass.....








@ King

I have been considering a ported blower. I would be more inclined to purchase a ported blower from someone that is looking at upgrading to a 2650 rather then send mine to the US, the shipping costs are so crazy that id prefer to pay someone a little extra and purchase their blower outright then putting the money towards shipping twice, there and back.

[Joshinator99]

Originally Posted by RobZL1

You sure can. That's how all the big power guys do it.

Can confirm I always launch in 2md gear.

[radz28]

A converter for A10s is really beneficial for second gear leaves, isn't it?

[2023_ZL1-AUTO]

Originally Posted by RHD ZL1

If you could look at your logs and let me know what the boost gain was from stock lower to 9.45 that would be great. I know that each car is a little different however at least I would have some kind of usable data like you mentioned. Thank you.

As others have mentioned, I personally wouldn’t be shifting the OEM Valve Springs and AFM Lifters to 7100+ rpm.

Sure, I ran 9.85 @ 139.85 with a 1.38 60ft.

Here is a discussion to what the car ran prior to fitting the 9.17 lower…… https://www.camaro6.com/forums/showt...=631571&page=2

I don't have FB as i cant stand it, a friend that does gave me this link, it is a vid of the pass. Hopefully it works.....

https://www.facebook.com/61558685641...49507279237509

@ King

I have been considering a ported blower. I would be more inclined to purchase a ported blower from someone that is looking at upgrading to a 2650 rather then send mine to the US, the shipping costs are so crazy that id prefer to pay someone a little extra and purchase their blower outright then putting the money towards shipping twice, there and back.

1) If I have all my logs with me, I'll check my boost numbers this morning. 2) WOW!! that's a great time slip! My first run was a 10.6xx, but I also buttered it off the line as I didn't know what to expect, I even left traction control and stabilitrak on like an idiot, I totally forgot about turn them off. 3) Check your messages about your last comment "I have considered..."

[Joshinator99]

Originally Posted by radz28

A converter for A10s is really beneficial for second gear leaves, isn't it?

In my opinion a mild converter helps with a second gear launch. Definitely helped my time for sure.

[KingLT1]

Originally Posted by clg82

I get the slap back to drive, and it's use for roll racing i've used that plenty.

Are you sure it's possible to start out in second gear?

You're not able to launch in second gear from a dead stop at a 1/4 mile track are you? I didn't think that was possible.

No I am not sure, I don't have a clue about this platform.

[2023_ZL1-AUTO]

I have two tunes, both are identical in every way except for, 1st tune is for manual mode 1st gear launch with auto shift and the 2nd tune is for manual mode 2nd gear launch with auto shift. This was for once I got to the track and judging how the track condition was and how my car was able to leave in 1st good or not good.

[radz28]

If I recall, for T93 cars, you can't start in 2nd. I don't think I could with my T87a conversion, when that was in the car. But - you had to roll to a stop in 2nd Gear. So - you're doing your burnout (in TUTD) and probably in a gear higher than 2nd, but you have to be in 2nd before you stop, and the TCM won't force a downshift into 1st if you've left TUTD in 2nd. I think that's how it had to be before, and don't know if it's changed with any definition updates in HPT.

Someone would have to chime in to correct me, but that's how later TCM-cars have to do it. You can't just start in 2nd. I'm totally in to learn otherwise though if anyone's generous enough to teach otherwise.

I think King's posted a how-to a while ago, too, on this, and that's what I used. CSP might have posted a video years ago, too.

[KingLT1]

That is correct...only 8l90 cars can actually select 2nd gear from a stop. The A10 stuff you have to chang the tune so it never commands a downshift to first gear in manual mode. I believe you have to be rolling when you put the car in manual mode and it will go into 2nd gear, then stop, and it will stay there. Been a minute since I physically drove one.

[SOCAL.M6.ZLE]

Originally Posted by ZLRob

These guys are all spot on the money here. The law of diminishing gains is SUPER applicable when you are talking about pulley changes and ramping heat production. On these cars, without proper supporting mods, overdrive lowers and/ or running smaller uppers is not advisable when running standard octane pump fuel, as you will introduce more and more heat soak and with that higher degrees of knock into the system. The factory tune maximizes the hardware already on the car by running a very aggressive calibration. To allow any appreciable gains to be had from pulleys you are talking about running ethanol. The higher the better until you can run full (many say full benefits are obtained at around E50 if I remember right, but my time in testing has shown different results).

Depending on your goals, the easiest thing to do, just to echo what Megahurtz said, is to run a ported stock TB, flex fuel sensor to allow for the most ethanol fuel allowable within your setup, green high flow filter (NOT A K&N or similar), and a pulley no larger than 5-9% over OEM size. I would also consider and recommend some sort of external LTR reservoir so you can minimize the chances of having air in the supercharger coolant loop setup.

I used to run a 5% 8.45" ATI lower pulley when I was more limited in my high side fueling, it still allowed a pretty decent amount of ethanol content with a more OE setup without heatsoak.

Food for thought: if you are chasing boost numbers, you are pursuing the wrong methodology, as boost is just a measure of engine restriction.

There are so many people off of this board who run much larger pulleys than OEM without any understanding of the actual harm that they do without proper supporting mods. Once you start going larger pulley sizes it turns into a modification cascading domino effect if you understand what each mod requires from your fueling system. These are not your old school supercharged vehicles that have room for expansion. They are close to maxed out from the box and without the supporting mods you can cause some serious harm to the engine REAL quick. Don't be like those people. Run the right combination of parts that works within your budgetary constraints, but keep the setup efficient and optimized for its combination. An efficient supercharger is a happy LT4!

Well said Rob... I agree with you and others about being careful with boost on a stock blower... the benefits of focusing on E85 first... cooling mods... and then porting the blower first. Man I wish these cars came with an ethanol sensor :(

[2023_ZL1-AUTO]

Originally Posted by radz28

If I recall, for T93 cars, you can't start in 2nd...

I'm not sure I'm talking about the same "thing" here, so I'll apologize now!

But, my 2nd gear start tune, basically doesn't have a 1st gear option, at all. Meaning, when I'm in manual mode, it immediately shows 2nd gear. on the dash. The process would be: I start my car, and I move the shifter left to manual mode, it immediately shows 2nd gear on the dash. Then, if I pull the shifter down to try and put trans in 1st gear, as soon as I left off the shifter it jumps right back to 2nd gear. If I pulled the shifter down and hold there, it will show 1st gear on the dash until I let off off the shifter. When I do, it jumps right back to 2nd gear.

A side note, the 2nd gear start tune only shifts 1st - 6th (It was setup for 1/4 mile drag stripe racing), there is not a gear above 6th I can shift into. I would have to pull the shifter back to the right and go back into full automatic mode to hit 7th - 10th.

[radz28]

Originally Posted by KingLT1

That is correct...only 8l90 cars can actually select 2nd gear from a stop. The A10 stuff you have to chang the tune so it never commands a downshift to first gear in manual mode. I believe you have to be rolling when you put the car in manual mode and it will go into 2nd gear, then stop, and it will stay there. Been a minute since I physically drove one.

Originally Posted by 2023_ZL1-AUTO

I'm not sure I'm talking about the same "thing" here, so I'll apologize now!

But, my 2nd gear start tune, basically doesn't have a 1st gear option, at all. Meaning, when I'm in manual mode, it immediately shows 2nd gear. on the dash. The process would be: I start my car, and I move the shifter left to manual mode, it immediately shows 2nd gear on the dash. Then, if I pull the shifter down to try and put trans in 1st gear, as soon as I left off the shifter it jumps right back to 2nd gear. If I pulled the shifter down and hold there, it will show 1st gear on the dash until I let off off the shifter. When I do, it jumps right back to 2nd gear.

A side note, the 2nd gear start tune only shifts 1st - 6th (It was setup for 1/4 mile drag stripe racing), there is not a gear above 6th I can shift into. I would have to pull the shifter back to the right and go back into full automatic mode to hit 7th - 10th.

OK. Both of you have reminded me now. I haven't used this in forever so I've forgotten. Your posts will clean-up what I was saying so others will understand.

Chris is right - I need to drive my car more... Thanks for the clarification guys!

[KingLT1]

Originally Posted by 2023_ZL1-AUTO

I'm not sure I'm talking about the same "thing" here, so I'll apologize now!

But, my 2nd gear start tune, basically doesn't have a 1st gear option, at all. Meaning, when I'm in manual mode, it immediately shows 2nd gear. on the dash. The process would be: I start my car, and I move the shifter left to manual mode, it immediately shows 2nd gear on the dash. Then, if I pull the shifter down to try and put trans in 1st gear, as soon as I left off the shifter it jumps right back to 2nd gear. If I pulled the shifter down and hold there, it will show 1st gear on the dash until I let off off the shifter. When I do, it jumps right back to 2nd gear.

A side note, the 2nd gear start tune only shifts 1st - 6th (It was setup for 1/4 mile drag stripe racing), there is not a gear above 6th I can shift into. I would have to pull the shifter back to the right and go back into full automatic mode to hit 7th - 10th.

Correct...to use second gear from a dig you have to disable 1st gear. Your tuner disables 7th gear shift because it's hard on the clutches. This was mainly done before enhanced tuning support was added in HPT 5.0 for the T93. Now I believe there is pressure control for gears 7-10 so it might be ok to WOT shift 7th gear with cars making a lot more power than stock.

[radz28]

Originally Posted by KingLT1

Correct...to use second gear from a dig you have to disable 1st gear. Your tuner disables 7th gear shift because it's hard on the clutches. This was mainly done before enhanced tuning support was added in HPT 5.0 for the T93. Now I believe there is pressure control for gears 7-10 so it might be ok to WOT shift 7th gear with cars making a lot more power than stock.

I'm sorry to the OP, but I suppose this little detour could be considered on-topic?...

King' - is it, still, a bad idea then, to not shift through multiple gears for the burn-out, then? Or am I mis-remembering, again... With the definitions from a couple years ago for the T93, if the appropriate ones are manipulated, is it safe to shift through multiple gears now, do you think?