[Daler]

Here’s a bit of a run down. My 2023 ZL1 shot a rod out because of fuel pressure failure and I decided to completely build my motor out. Because of my bad previous experiences with e85 I decided I want to do 93 first and then ease into some modifications for e85 later. I want somewhere around 750-770 WHP.

Here’s the setup:
Kong Stage X Ported LT4 Blower and rebuild
103 MM TB
2 Inch Kooks Headers Catless
Roto Fab Big Gulp
Griptech 2.3 Upper Pulley, Stock Lower
Stage 1 FI interchiller
DSX Aux Pump
OEM heads ported
Massive cam (wasn’t given a stage, custom grind)
Circle D TQ Converter
Thompson engines LT1 416 Short Block rated for 1200 Crank HP

Any help would be greatly appreciated. Do I need to change up my mod list to run 93 safely? Is my target WHP number aiming to high? Whatever needs to be changed please let me know, don’t want to run into this expensive issue again!!

[KingLT1]

That setup should make 750 easy on 93. The larger cam bleeding off dynamic compression should allow 93 to go a little further. I would say you can get close to 800 on good pump 93.

What issue have you had with E85? I have experienced none and have been running it for years. Your setup would pick up a lot of power on even a E50 blend.

[Daler]

To explain it more in depth, basically prior to all of this I had an intake, catback, 2 inch kooks headers, and a 2.3 Pulley. It was tuned on e50 with my DSX flex fuel sensor and literally the second day it started misfiring multiple times on pulls and blew up. At that time it was at e35 when it blew because I filled more 93 in it because it was cold that day. It was working very well on be Dyno and when I took it right from the shop it was running perfect. Once it got cold then it seemed to start having this fuel pressure issue. Tuner told me fuel pressure dropped to 300-500 every time I did a pull which is a very big no no. But the thing is when I sent to to my buddy’s shop go get built there was so much damage in the bottom end the at he said it wasn’t a HPFP issue, he says maybe too much boost or bearing blew out and then cause a rod to get shot and screw the motor up completely, nothing was salvageable except for the heads surprisingly. What do you think the issue was, defective motor or some sort of part maybe??

[Megahurtz]

Cold weather increased the demand of fuel volume and you were likely already on the edge in warmer weather. Cold weather tanked the fuel pressure and your EOI went into the land of detonation and blew your motor. I've seen this before when people don't know what their real limits of Ethanol are for their build.

[KingLT1]

Originally Posted by Megahurtz

Cold weather increased the demand of fuel volume and you were likely already on the edge in warmer weather. Cold weather tanked the fuel pressure and your EOI went into the land of detonation and blew your motor. I've seen this before when people don't know what their real limits of Ethanol are for their build.

Agree!

[JSH]

Originally Posted by Daler

It was tuned on e50 with my DSX flex fuel sensor and literally the second day it started misfiring multiple times on pulls and blew up.

You didn't describe the dyno/ logging/ studying/tuning in detail so I'll add that it has to be carried out in small increments. We made nine pulls over a day a week ago to get it done. Understanding a log takes 30 min

[Daler]

Originally Posted by KingLT1

That setup should make 750 easy on 93. The larger cam bleeding off dynamic compression should allow 93 to go a little further. I would say you can get close to 800 on good pump 93.

What issue have you had with E85? I have experienced none and have been running it for years. Your setup would pick up a lot of power on even a E50 blend.

Do you think that the boost created by the 2.3 is sustainable on just 93?

[Daler]

Originally Posted by Megahurtz

Cold weather increased the demand of fuel volume and you were likely already on the edge in warmer weather. Cold weather tanked the fuel pressure and your EOI went into the land of detonation and blew your motor. I've seen this before when people don't know what their real limits of Ethanol are for their build.

At the time it blew it was on e35 so well below the limit the stock fuel system can handle. If I’m being honest, neither my tuner, gm, or my performance ship building my car know exactly what happened at all expect that fuel pressure dropped a lot. They called it basically a 1 of 1 issue.

[Daler]

Originally Posted by JSH

You didn't describe the dyno/ logging/ studying/tuning in detail so I'll add that it has to be carried out in small increments. We made nine pulls over a day a week ago to get it done. Understanding a log takes 30 min

My tuners pretty good, best in my city, he’s known for doing all the super high hp cars down here in my state and he’s trusted among many so it was a no brainer to go to him cause he’s done high HP lt4’s all the time. He showed me the logs when he was tuning it on the hub Dyno and there was literally nothing wrong at all. When I took it out of the shop to give it a ride after he was done it was running perfect. When I went home to drop my car off and come back to pay and pick up the car is when it got a little colder and then it started to drop fuel pressure and misfire. It’s just very odd to me what happened.

[Megahurtz]

Originally Posted by Daler

At the time it blew it was on e35 so well below the limit the stock fuel system can handle. If I’m being honest, neither my tuner, gm, or my performance ship building my car know exactly what happened at all expect that fuel pressure dropped a lot. They called it basically a 1 of 1 issue.

E35 on the stock fuel system with a Kong X port, a 2.3 upper and cold weather is not well below the limit of the stock fuel system. I tune a lot of these cars with Flex Fuel. Unless you live somewhere in a high altitude zone, you're already on the edge with E35 in decent weather. Let it get cold and the demand goes way up and the fuel pressures will fall off a cliff. It's not a gradual drop when you're on the edge, its more like falling off the cliff.

I could be wrong, I wasn't there. But if I had to bet, I would still bet a loss of fuel pressure was the cause. I only offer the advice so that you don't make the same mistake twice.

[SOCAL.M6.ZLE]

Great thread and learning experience for all... To the OP, so sorry this happened.

Question to all; is there no way to safeguard this event from happening with the tune? I thought the KR sensors were suppose to kick in and save us in those instances?

Perhaps an AFR gauge in your face is the best safeguard? or... maybe a Banks iDash with rail or low side pressure posted for constant monitoring?

[Katech_Mike]

Originally Posted by Megahurtz

E35 on the stock fuel system with a Kong X port, a 2.3 upper and cold weather is not well below the limit of the stock fuel system. I tune a lot of these cars with Flex Fuel. Unless you live somewhere in a high altitude zone, you're already on the edge with E35 in decent weather. Let it get cold and the demand goes way up and the fuel pressures will fall off a cliff. It's not a gradual drop when you're on the edge, its more like falling off the cliff.

I could be wrong, I wasn't there. But if I had to bet, I would still bet a loss of fuel pressure was the cause. I only offer the advice so that you don't make the same mistake twice.

I agree with this.

Also why I'm not a fan of running blends. They really need to be baby sat and most of my customers do not want the hassle of consistently logging.

[ZL14ever]

Originally Posted by Megahurtz

E35 on the stock fuel system with a Kong X port, a 2.3 upper and cold weather is not well below the limit of the stock fuel system

Yup. My car has similar setup and it is already at the edge on E25 fuel

[SOCAL.M6.ZLE]

Originally Posted by Katech_Mike

I agree with this.

Also why I'm not a fan of running blends. They really need to be baby sat and most of my customers do not want the hassle of consistently logging.

But would someone not have the same issue running straight E85?
or, are you tuning the car based on the coldest anticipated weather they might see?