[Ajs16400]

I have now come full circle and back to the lt4 after i foumd out the 2300 is discontinued and cannot be found.

Few questions I have with a lt4 low and high fuel pump and injectors can i run it on e85? If not what about if i add the low side booster?

I have heard of the heat issues with them but i am not looking to go crazy power just the base of what the normal WeaponX or tps motorsports kit does.

I am still open and hope to finding a maggie 2300 used just weighing my options as after some reading the lt4 might be the better option for my power levels i am looking for.

[KingLT1]

The LT4 fuel system high to low with a JMS booster will handle E60 on about 8psi or E80 on 6psi. Most pump E85 is actually between E65-E80.

Adm performance was able to run full pump E85 with the LT4 supercharger pullied up to 6 psi combined with LT4 fueling on a SS. The car made 600whp with that setup on their dyno. I believe that was a M6 car, so expect a little less with a A8.

Heat isn't as big of a issue with the LT4 supercharger on a LT1 because you can make similar power to a ZL1 with less boost due to the LT1 having 1.5 point higher compression. The heat issues you are reading of are with ZL1/Zo6's when guys try to pulley them down and spin them past their efficiency range. 9-10psi is about max for a stock LT4 without porting before it starts becoming a heat pump.

The LT4 setup on a LT1 with E85 @ 6psi would make a very efficient, fun, and reliable combo. Again if you don't mind mixing, then you could run a little more boost on E60.

[Eldi Z]

Originally Posted by KingLT1

The LT4 fuel system high to low with a JMS booster will handle E60 on about 8psi or E80 on 6psi. Most pump E85 is actually between E65-E80.

Adm performance was able to run full pump E85 with the LT4 supercharger pullied up to 6 psi combined with LT4 fueling on a SS. The car made 600whp with that setup on their dyno. I believe that was a M6 car, so expect a little less with a A8.

Heat isn't as big of a issue with the LT4 supercharger on a LT1 because you can make similar power to a ZL1 with less boost due to the LT1 having 1.5 point higher compression. The heat issues you are reading of are with ZL1/Zo6's when guys try to pulley them down and spin them past their efficiency range. 9-10psi is about max for a stock LT4 without porting before it starts becoming a heat pump.

The LT4 setup on a LT1 with E85 @ 6psi would make a very efficient, fun, and reliable combo. Again if you don't mind mixing, then you could run a little more boost on E60.

and what about running straight 93 without E? What is a "safe" boost level and what kind of WHP can be expected on such boost level (keeping ignition timing/advance and injector ms in check)?

[wnta1ss]

I think the key to the heat issues with the 1740 is to spin them slower. Remember that the ZL1 has lower compression than the LT1 as KingLT1 mentioned, so they run 10~11 psi of boost on those stock. Then some ZL1 guys spin them even faster for more boost, and the little blower is making a bunch of heat then. When you install the 1740 on an LT1, my opinion is that you should spin it slower (like larger pulley on the supercharger) than on the ZL1, because you will make ZL1 power with less boost, and your IATs will be better. As KingLT1 was talking about, ADM slowed one down a good bit, and then were able to use E85 with just LT4 fuel parts. Efficiency, they made good power, and with the blower not spinning like crazy, it will probably be more consistent power, because temps won't go through the roof. Also with the crapshoot of LT1 ring gaps, using E85 helps cool things down, therefore lessening the chances of sticking a ring and breaking a piston.