[L78toLT1]

Well, OP, you have certainly dived headfirst into the modding rabbit hole! One thing I'm curious about is why you haven't added a flex fuel sensor. If e85 is available in your area, I would certainly recommend this simple and comparatively inexpensive mod. Running e50 - 60 will net you a bigger power bump than you have realized with all of your current mods.

[2023_ZL1-AUTO]

Originally Posted by L78toLT1

Well, OP, you have certainly dived headfirst into the modding rabbit hole! One thing I'm curious about is why you haven't added a flex fuel sensor. If e85 is available in your area, I would certainly recommend this simple and comparatively inexpensive mod. Running e50 - 60 will net you a bigger power bump than you have realized with all of your current mods.

I am going e85, I live in corn field OHIO! So e85 is readily available here in Columbus. That one benefit of Columbus having the nick name "Cow Town"
This is the one I used. It was very stout. Also I was only going from 3" to 3" sou I only needed enough expansion to allow the o.d 3" to slip into the i.d of the 3" I expanded. Hope it helps!

[2023_ZL1-AUTO]

Last night I added the AEM AFR Gauge to my ZL1. I removed the secondary Banks iDash Gauge I had. This way I could fit it in the lower gauge position in my ZZ Performance dual A-Pillar pod. I will post a pic later. It was pretty easy to get it wired and working. I used the purple and black wires on the wiring connector under the center console for switch power. The only thing that might not be perfect is the angle of the AFR Bosch sensor. But I'll deal with that later as I really only need this for my HP Tune.

[2023_ZL1-AUTO]

Quick update: My AEM AFR gauge is showing pretty rich (at least I think), hope I don't foul my new NGK Iridium's! It shows 18.84 at cold start then 17.56 to 15.92 during data logging. Also, I downloaded and installed the Android HPTuners TDN app and read my cars ECM and the other controllers, synced with CSP Racing via my invite code and now the magic will happen at the hands of Andrew !!!

[WhiteMale]

Originally Posted by 2023_ZL1-AUTO

when I was leaving and saw two people walking out. I thought to myself, I better wait to start this beast until they are away. But they kind of were lollygagging so I started it anyway. I kid you not, when it fired up one of the ladies jumped out of her skin. It totally scared the crap out of her when it fired up! It was actually kind of funny!

I sometimes look over my shoulder and think that I should wait, let them pass by and then nope...hit it. Its funny to watch people get roused by an LT4 cold start. I use the MBRP axle back which is basically a muffler delete (no headers).

[RobZL1]

Originally Posted by 2023_ZL1-AUTO

Quick update: My AEM AFR gauge is showing pretty rich (at least I think), hope I don't foul my new NGK Iridium's! It shows 18.84 at cold start then 17.56 to 15.92 during data logging. Also, I downloaded and installed the Android HPTuners TDN app and read my cars ECM and the other controllers, synced with CSP Racing via my invite code and now the magic will happen at the hands of Andrew !!!

The values you are seeing are above stoich, which is lean. You should be seeing 14.7 +/- 1 or so while cruising around. This is indicative of an air leak, either at the bung, ahead of the bung, or just past the bung (like if you have a clamp a few inches downstream of the bung). Most likely I'm guessing it's a nearby clamp. You'll need to get that fixed before Andrew tunes it.

I would also suggest swapping to Lambda instead of AFR in the gauge. It will be easier to start speaking lambda instead of AFR now, and particularly once you go to flex fuel.

[2023_ZL1-AUTO]

OK... So I was wrong on the higher number was meaning rich. I also thought long tubes caused a car to run lean? So, you are indicating I may have an exhaust leak? So I didn't use type of "silicone" obviously. But, I tighten the clamps down as much as my 3/8 drive impact could go. Would you suggest I switch to my 1/2" drive impact and redo all clamp bolts? Or run it to a reputable exhaust shop and let them re-tighten all? I want to skip having them welded is possible. Thanks

[RobZL1]

Originally Posted by 2023_ZL1-AUTO

OK... So I was wrong on the higher number was meaning rich. I also thought long tubes caused a car to run lean? So, you are indicating I may have an exhaust leak? So I didn't use type of "silicone" obviously. But, I tighten the clamps down as much as my 3/8 drive impact could go. Would you suggest I switch to my 1/2" drive impact and redo all clamp bolts? Or run it to a reputable exhaust shop and let them re-tighten all? I want to skip having them welded is possible. Thanks

If you're reading 16-18 AFR, then you are definitely picking up extra air somewhere. Perhaps the wideband is not tight? Adding headers won't make it run lean, per se. The car will adjust using the narrowbands to bring it back to stoich under normal driving (non-WOT) situations.

With those clamps, they are notorious for leaking even if you crank them to death. Most people swap out the speed engineering clamps for better band clamps, or put some copper goop on the joint.

It's also possible that since you've been through a few heat cycles, things just need to be retightened.

Regardless, you're definitely picking up a leak somewhere. With your mods, even un-tuned, you should be reading around stoich, not as lean as currently indicated.

[2023_ZL1-AUTO]

RobZL1 Thanks! I did a data log on a short 20 minute trip. So I'm only at those higher numbers when 1) it first start it up or, 2) at a short idle vs letting it sit there for a while and idle, or, 3) when I've let off the throttle coming to a stop. So, this just proves I'm not really knowledgeable about all this stuff. When I was cruising, 35 to 45 to 55, AFR was between 14.2 and 15.4, when I would hit the throttle hard, it would go to 13's and a few blips into the mid 12's. I'll get it back on my QuickJake's and retighten all bolts and retorque headers!

[RobZL1]

Good deal. It's probably just a minor leak then. Sounds like when you are cruising it's not sucking in any air, so it might be good. Couldn't hurt to do a retorque just in case. But letting off throttle, it will read high/lean due to DFCO (deceleration fuel cut off). First start up or short idle can be all over the place, though not to that extreme usually.

Anyway, the retorque will likely take care of it- since you are in range while cruising, you likely don't have much of a leak.

Regarding the 13's and mid 12's you are seeing when you goose it, that's where it's going into open loop, and starting to settle into PE (Power enrichment). Andrew will likely target something around 12.1 to 12.4 when he tunes it (0.82 - 0.84 lambda). The reason to stay out of the throttle until it's tuned is to prevent it from being lean in open loop (where there is no feedback to correct fueling). this is where you see it being lean from adding headers. Since these are usually rich from the factory, you may be very close to optimal as you sit now. If you get on it and it settles down to 12.2 or 12.3, then you're pretty close to a decent AFR. If it stays in the high 12's and 13's, don't go WOT until it gets tuned... don't want you to go boom!

[2023_ZL1-AUTO]

Thanks RobZL1 ! Roger That !

[2023_ZL1-AUTO]

Today Andrew from CSP Racing send me my first tune file to flash. I'll upload and log and send back the results! Exciting day knowing I'm getting that much closer !!!

[radz28]

If I can offer a recommendation to think about:

Try to think in EQ, not AFR. It will make thinking about fueling a lot easier. You'll have to transition your gauge, too. JMHO.

And - are your shipping spacers still in the springs?

[2023_ZL1-AUTO]

rad! Thanks!!! Will do!!

Also I'm at a client that has a full fledged Fleet mechanic shop, asked if they would put it on one of the lifts and see if they saw an exhaust leak. They found (2) leaks right at the CATs going to exhaust/X-Pipe. Get it fixed as I type !