[LT1ornothing]

Originally Posted by prostcj

I have an LT1 and putting a NOVI 1500 on it. The tuner is going to give me two calibrations. One for street use and one for autox and road course with presumably more timing pulled. I discussed upgrading the fuel system for E85 but the parts and install would be close to 5K. The other wrinkle is I live in the PNW and E85 is limited.
He suggested if I only plan to take it to a road course a couple times a year that a cheaper option would be to mix in 5 gal of 110 octane with each tank before track days. This would provide some extra safety margin and should only run me a couple hundred dollars a year.
Is there something I'm missing here? I imagine most of us will only track our cars a handful of times a year and just buying the race fuel as needed would make more sense.

On 93 octane, you won't be able to run much timing, and I am guessing 92 octane is the best you can get in your area. If you can't upgrade your fuel system, you may have to change the cog pulley to lower the boost.

[KingLT1]

Originally Posted by prostcj

I have an LT1 and putting a NOVI 1500 on it. The tuner is going to give me two calibrations. One for street use and one for autox and road course with presumably more timing pulled. I discussed upgrading the fuel system for E85 but the parts and install would be close to 5K. The other wrinkle is I live in the PNW and E85 is limited.
He suggested if I only plan to take it to a road course a couple times a year that a cheaper option would be to mix in 5 gal of 110 octane with each tank before track days. This would provide some extra safety margin and should only run me a couple hundred dollars a year.
Is there something I'm missing here? I imagine most of us will only track our cars a handful of times a year and just buying the race fuel as needed would make more sense.

The Toohighpsi system is around 2k. You should be able to get that with PI injectors, with JMS booster for around 3k.

Your engine isn't going to last long with boost on 93 with road course racing. So E85 could get you several more years of use out of the stock bottom end.

[LT1ornothing]

Originally Posted by KingLT1

The Toohighpsi system is around 2k. You should be able to get that with PI injectors, with JMS booster for around 3k.

Boy I sure wish I had the funds for his port injection kit. Would be nice to pump straight e85 in and tune it on some decent timing.

Your engine isn't going to last long with boost on 93 with road course racing. So E85 could get you several more years of use out of the stock bottom end.

[JimGnitecki]

Originally Posted by KingLT1

. . .

Your engine isn't going to last long with boost on 93 with road course racing. So E85 could get you several more years of use out of the stock bottom end.

To what extent does the above apply to the OEM ZL1?

I'm asking because I have never considered an OEM American supercharged car to be suitable for road course racing. I've always viewed them as street hotrods that can be used as daily drivers if driven conservatively versus aggressively (i.e. no prolonged WOT operation).

Jim G

[LT1ornothing]

Originally Posted by JimGnitecki

To what extent does the above apply to the OEM ZL1?

I'm asking because I have never considered an OEM American supercharged car to be suitable for road course racing. I've always viewed them as street hotrods that can be used as daily drivers if driven conservatively versus aggressively (i.e. no prolonged WOT operation).

Jim G

An oem ZL1 LT4 has 10:1 engine compression and forged internals, both of which are safer for 93 octane + blower. .

The LT1 has cast pistons and 11.5:1 compression ratio, both of which are NOT favorable for 93 octane + supercharger. A stock LT1 needs e85 to run boost safely.

[prostcj]

Originally Posted by KingLT1

The Toohighpsi system is around 2k. You should be able to get that with PI injectors, with JMS booster for around 3k.

Your engine isn't going to last long with boost on 93 with road course racing. So E85 could get you several more years of use out of the stock bottom end.

I guess my question is will mixing 110 octane with 92 to bring the octane up closer to 97-98 octane be a suitable safety measure or are there other advantages of Ethanol? I am guessing an E50 mix is around the same effective octane rating give or take.

[prostcj]

Originally Posted by KingLT1

The Toohighpsi system is around 2k. You should be able to get that with PI injectors, with JMS booster for around 3k.

Your engine isn't going to last long with boost on 93 with road course racing. So E85 could get you several more years of use out of the stock bottom end.

The costs from my tuner seems reasonable:
LT4 HPFP $850
LT4 FI $632
DSX low side $1000
DSX Flex Fuel kit $300

So that adds up to about 3k but then when you add labor, tuning, and tax it is about $4600.

A lot cheaper than an engine rebuild though.

[KingLT1]

Originally Posted by JimGnitecki

To what extent does the above apply to the OEM ZL1?

I'm asking because I have never considered an OEM American supercharged car to be suitable for road course racing. I've always viewed them as street hotrods that can be used as daily drivers if driven conservatively versus aggressively (i.e. no prolonged WOT operation).

Jim G

It doesn't...as already mentioned the ZL1 is lower compression, stronger pistons, and rings that are gapped for boost. The LT1 is high compression with tight ring gaps. Ethanol lowers cylinder temps several hundred degrees vs pump gas upon combustion and that keeps the rings from butting and breaking the piston. The LT4 can run 93 Without much issue even though it's still octane limited.

A lot of it will come down to how the car is used as I already mentioned in this thread.