[AndyUK]

Originally Posted by EDFHOBBIES

Every car is different whipple is claiming 600 at the wheels with no other mods.. so cai and headers would be at that 620 mark easy. So I think it depends on what your running (how much air your system moves) turbos, whipple, maggi, or eforce to when you need the fuel pumps or injectors...

I just saw a local shop I'm in houston make 770 on a zl1 with a pulley and e85.

I'm thinking the zl1 is worth the extra money now if it's gonna take a 5k fuel system plus labor.

I know a couple of guys with Mustang whipples and they dont always live up to the marketing numbers when run on more realsitic dynos.

[EDFHOBBIES]

I agree but the LT1 stuff has been pretty dead on. My eforce made exactly as advertised seems this maggie did to whem stock. There's is a 2.9 so seems realistic. Honestly all the kits stock seem be with in a few hp of each other. The high compression of the LT1 seems to be the limiting factor. They are all hungry for more octane.

[parish8]

I love it. Some actual technical information on the fuel system.

That zl1 is also running meth so it is hard to say exactly the stock zl1 fuel system can handle.

It is hard for me see how the $500ea injectors would get you any farther than a lt4 injector. I expect even the modified hp pump to run out before the stock lt4 injectors. Maybe once you get the lash cap and modified lobe that changes. Time will tell on this one. My plan is the $1500 hp pump with stock lt4 injectors and a serious low side upgrade.

With 340deg of crank rotation at 6500rpm you should have over 8ms of spray time. Just like above I have no personal experience but hope to soon. I hear some people say to not go over 6ms and other that say 8ms is the limit.

[sub_ETCS_ret]

Originally Posted by parish8

I love it. Some actual technical information on the fuel system.

That zl1 is also running meth so it is hard to say exactly the stock zl1 fuel system can handle.

It is hard for me see how the $500ea injectors would get you any farther than a lt4 injector. I expect even the modified hp pump to run out before the stock lt4 injectors. Maybe once you get the lash cap and modified lobe that changes. Time will tell on this one. My plan is the $1500 hp pump with stock lt4 injectors and a serious low side upgrade.

With 340deg of crank rotation at 6500rpm you should have over 8ms of spray time. Just like above I have no personal experience but hope to soon. I hear some people say to not go over 6ms and other that say 8ms is the limit.

I'm curious as to your goal with this? Are you trying to achieve max horsepower, find out which pieces give you the best bang for your buck, or something else altogether?

I'm personally curious about maximum achievable results with lt4 injectors then each of the pumps and finally the entire system.

[parish8]

My eventual goal is added port injection and over 1000hp but for this year I want to max out a stock then modified di fuel system using e85.

I want to personally see the hard limit of the stock low pump, the stock high pump, then see what the stock lt1 injectors can do and try pushing them to 8ms. Eventually find out what the limiting factor is once the $1500 hp pump and lt4 injectors are in. It sounds like we have similar goals.

[sub_ETCS_ret]

Originally Posted by parish8

My eventual goal is added port injection and over 1000hp but for this year I want to max out a stock then modified di fuel system using e85.

I want to personally see the hard limit of the stock low pump, the stock high pump, then see what the stock lt1 injectors can do and try pushing them to 8ms. Eventually find out what the limiting factor is once the $1500 hp pump and lt4 injectors are in. It sounds like we have similar goals.

Great! Thanks.

[Perdieu]

Originally Posted by toohighpsi

Yes that is the pump I'm running, it is a direct bolt in upgrade with stock cam, but will also work with some of the bigger cam lobes.
I ran out of fuel with the stock pump at about 620RWHP.

With the big pump I have been able to run up to the 690 RWHP number (with a 50/50 water meth mix through a 1000cc/min nozzle) at which point my low pressure side is down to about 30psi and I'm very close to the LT1 injector limit with a 6.5ms pulsewidth. I could probably make it to 700RWHP on the dyno, but wouldn't want to run it at the track without at least some amount of margin.

Any reason what you didn't use a LT4, CTS-V, ZL1 pump ?? Cost saving would be huge.

Originally Posted by EDFHOBBIES

We Probably need to go to the vette forum.. did you see those prices 500 bucks for injectors, 1500 for a pump.. 5k I though the 5k sytem was left with my 5th gen for squash or fore. That's nuts.. I may get a mustang lol

You can get the LT4 pump and 8 injectors for around 1500.. or the LT4 Pump and the 2017 Corvette highflow injectors for the same (they have 3 different injectors avai.)

[toohighpsi]

Originally Posted by EDFHOBBIES

Every car is different whipple is claiming 600 at the wheels with no other mods.. so cai and headers would be at that 620 mark easy. So I think it depends on what your running (how much air your system moves) turbos, whipple, maggi, or eforce to when you need the fuel pumps or injectors...

The ability to hit 600 RWHP isn't a function of the SC, it's limited by fuel octane and IAT on these high compression engines. Virtually every SC we're talking about here has the capability of making 1000 HP at the crank, managing detonation and fueling are the keys to making power.

With that I'll also kindly avoid commenting on some manufacturers marketing techniques...

[Atomic Ed]

Originally Posted by Perdieu

Any reason what you didn't use a LT4, CTS-V, ZL1 pump ?? Cost saving would be huge.



You can get the LT4 pump and 8 injectors for around 1500.. or the LT4 Pump and the 2017 Corvette highflow injectors for the same (they have 3 different injectors avai.)

Took me a lot of research to figure out the 3 different injectors listing. The "low" injector is for the LT1s in the trucks. The "nominal" is for the SS, and the "high" is for the LT4.

[Perdieu]

Originally Posted by Atomic Ed

Took me a lot of research to figure out the 3 different injectors listing. The "low" injector is for the LT1s in the trucks. The "nominal" is for the SS, and the "high" is for the LT4.

hmmm in theory that sounds good.

But when pulling parts off my vin number and one other 2017 it show 3 injectors for the Camaro SS

Pulling the vin of ZL1 today it only shows 2 Low and Nominal..

[EDFHOBBIES]

Originally Posted by toohighpsi

The ability to hit 600 RWHP isn't a function of the SC, it's limited by fuel octane and IAT on these high compression engines. Virtually every SC we're talking about here has the capability of making 1000 HP at the crank, managing detonation and fueling are the keys to making power.

With that I'll also kindly avoid commenting on some manufacturers marketing techniques...

Yes that is true but fuel system to fuel system differs in the amount it actually runs out.. for instance I was out of fuel at 640 rwhp with a eforce then I went twin turbo no other changes made I now make 750 with the same fuel system. No meth no e85.. and u see the old zl1 pump was good to 650 rwhp on sc and 700 something on a centri or turbos. Why cause they move more air quicker and more efficiently on a pull. The power does come with tweaking timing and lower iats. But saying the same fuel system was good for 640 on one setup and 750 on another. So yes if the whipple can do more which it will since it's so much bigger the iats will be lower becasue it's not spinning or working so hard to make the same psi or flow most of the heat is generated from compressing the air hense the iats will be lower.

These blower are to small ever to make 1000 hp or 875 rear wheel hp by the time you lower the compression 1.9l or 2.3l won't do it. With out the help of nos, e85, and meth join together.

How ever my TT will do it with 1 spring change and e85 hell I'll be 1200 hp

[JoeAyalaM]

The SC take much more crank HP than a Turbo to compress intake air, and a cooler charge air will help prevent pinging, so a difference in total output is to be expected using the same fueling system.

[toohighpsi]

Originally Posted by parish8

I love it. Some actual technical information on the fuel system.

That zl1 is also running meth so it is hard to say exactly the stock zl1 fuel system can handle.

It is hard for me see how the $500ea injectors would get you any farther than a lt4 injector. I expect even the modified hp pump to run out before the stock lt4 injectors. Maybe once you get the lash cap and modified lobe that changes. Time will tell on this one. My plan is the $1500 hp pump with stock lt4 injectors and a serious low side upgrade.

With 340deg of crank rotation at 6500rpm you should have over 8ms of spray time. Just like above I have no personal experience but hope to soon. I hear some people say to not go over 6ms and other that say 8ms is the limit.

That's what I'm heading to with the Camaro, Big Bore HP pump, LT4 injectors, and a low side upgrade (boost a pump or new intank) The HP DI pump is a positive displacement unit, so it's not critical to maintain a specific low side pressure, just enough so that you don't cavitate the inlet of the HP pump. Fuel is essentially incompressible so trying to run a high inlet pressure on the low side really won't buy you much.

I agree on the Injector max PW, but although the calculations say that, I was unable to achieve it. Once I hit about 6.9ms it's all over and it will start missing. I have found some places to improve with SOI (start of Injection) and EOI, but nothing groundbreaking so far.

[parish8]

Originally Posted by toohighpsi

That's what I'm heading to with the Camaro, Big Bore HP pump, LT4 injectors, and a low side upgrade (boost a pump or new intank) The HP DI pump is a positive displacement unit, so it's not critical to maintain a specific low side pressure, just enough so that you don't cavitate the inlet of the HP pump. Fuel is essentially incompressible so trying to run a high inlet pressure on the low side really won't buy you much.

I agree on the Injector max PW, but although the calculations say that, I was unable to achieve it. Once I hit about 6.9ms it's all over and it will start missing. I have found some places to improve with SOI (start of Injection) and EOI, but nothing groundbreaking so far.

more good info. thank you!

at 6500rpm and 7ms(38%dc) the lt4 injectors calculate out to be good for 700hp on e85 using .9bsfc.

I will be happy if I can get to 700hp on e85 with di. that power level will hold me for a year or so.

I wonder what the real limit of soi is. maybe there is some delay compared to when it is commanded to start and stop. maybe we can start it before 359deg btdc? what are the negatives to starting the injection too soon? I could see sending some fuel out the exhaust at some point and maybe mess up the wideband or the wideband reading.

my question at this point is will the lt4 hp pump feed the lt4 injectors at 7ms or is the big bore pump needed for this. I don't really want to spend money on a part this is oversized compared to other parts if I can help it.

can I see your tune file?