2017 ZL1 6 speed makes less with mods

[NigelBST]

We have one here that came in with a Rotofab intake and baselined it. Made 584 on 10-11psi. The C7Z we just did made mid 550s stock so that seemed on par since it had an intake already.

We added Kooks 1 7/8 longtubes, Kooks exhaust, Innovators West lower with 9.1 ring and ProSpeed AutoSport heat exchanger. It makes 13-14psi. Now the best I've gotten is 566.

We just did a 16 C7Z and it picked up around 130whp with the same mods. The ZL1 is super sensitive to timing too compared to the C7 Z06 we just did with almost the same mods. The C7Z is not quite as overdriven and makes 11-12psi. Even with the knock sensors turned off it doens't make anymore power.

If I keep the timing super low it won't knock but of course makes really low power.

Any input would be great! I've been on the dyno with this thing for a few days now trying small changes and I'm getting nowhere.

Thanks

[NigelBST]

I'm not sure how to upload the file but if someone gives me an email I'll send it.

[Ben Charles]

Probably Bc your not allowing the ECU to make more power... so it makes about the same

[NigelBST]

I've seat torque vs gear to 6042 and added %25 to Peak Torque. At one point I had peak torque at 6042 as well. I've also added %20, and at one point another %25 to driver demand tables above %70 throttle. I'm commanding %100 throttle during the pulls and getting %84, this information is verified via the logs.

[NigelBST]

Update:

Looks like my dyno randomly decided to mess up. Or read differently. However you wanna say it. Put my 225k mile Tahoe on the dyno and it's down 50hp from December of 15. I'm sure some of that is wear and oil changes that are drug out too long, but it's not all of that.

I've been going crazy over this. Now to see if Dyno Dynamics can get it fixed for me.

[Area47]

Update:

Looks like my dyno randomly decided to mess up. Or read differently. However you wanna say it. Put my 225k mile Tahoe on the dyno and it's down 50hp from December of 15. I'm sure some of that is wear and oil changes that are drug out too long, but it's not all of that.

I've been going crazy over this. Now to see if Dyno Dynamics can get it fixed for me.

weather corrections entered correctly? vehicle weight? resistance? there is A LOT of factors at play with that difference. In awd mode i can pick up 50whp from 2wd mode on a DD dyno without changing anything in the car, or weather corrections.

[paulsmithsr]

post tune if u want help

[NigelBST]

weather corrections entered correctly? vehicle weight? resistance? there is A LOT of factors at play with that difference. In awd mode i can pick up 50whp from 2wd mode on a DD dyno without changing anything in the car, or weather corrections.

It's a 2WD DynoTech model I've been using for almost 2.5 years with no issues. I've never used an older one but my only options here are are drivetrain weight in KG and ramp speed. Same SAE weather correction too. It's only been a week since it's been on the dyno and I've done a few cars in between.

I spent 35mins on the phone with the US portion of DD and we recalibrated the load cell. It was off by 7lbs but he said that's not enough to make that big of a difference. He took note of the info and sent some stuff to the Australian office for them to check out when they can. I left my dyno computer on all night and it looks like they logged in but I haven't heard anything else back.

Right before I put the ZL1 back on I put a customer's F-Body on that had just converted to a turbo 350 from a T56. Everything was exactly the same and to the wheels on what was a 800+ whp car we lost around 150whp. I thought it seemed like a lot but it's not like it was a high end converter either so I figured it was just losing a decent amount there.

It's worth noting that if I put the stock tune in a do a pull the ZL1 makes 480-490, but then you get into the fact the PCM isn't being told to allow more power etc so it's not a solid comparison.

[NigelBST]

post tune if u want help

I don't see the function to do so or I would.

[5FDP]

Advanced reply, attachments. Is how you post tunes.

[lt1z350]

so did you get this worked out?

[Tre-Cool]

Update:

Looks like my dyno randomly decided to mess up. Or read differently. However you wanna say it. Put my 225k mile Tahoe on the dyno and it's down 50hp from December of 15. I'm sure some of that is wear and oil changes that are drug out too long, but it's not all of that.

I've been going crazy over this. Now to see if Dyno Dynamics can get it fixed for me.

I've got a dual retarder dyno dynamics. I've had a similar thing occur a few times. either consistent 200whp cap suddenly starts making 250whp or a turbo ls making 580whp struggles to make the same power after switching to e85.