[cjperformance]

This is just postulation and estimation so dont take this as anything else.

I dont have dyno numbers, but with dsx low side and lt4 high side fuel, p1x, and everything else stock... airflow peaks around 78 lbs/min normally with some outliers around 84. If you go by 9 to 10 hp/lb that puts it in the 700 to 780 range at the engine... around 5.5 ms inj, so some overhead still on E50.

Dont know about rwhp... maybe 620-ish? If you take 85% of engine hp. So... to me low 600-620 rwhp seems very doable with lt4 fueling on lt1... it would seem reasonable based on inj pw that 670+ rwhp would put things much closer to the limit. So if my power goal was 670+ at the wheels.... prob go with something better than lt4 + stock cam.

Of course the greater the E content, the more that overhead will be consumed.

[JP374]

Originally Posted by KingLT1

No sir I am not confused...I can go back to 2017-2019 and bring up posts that we have taken part in where it has pretty much been stated several times that 620whp is where a stock cam LT1 maxes the LT4 fuel system @ E60. That isn't a hard number buy any means.. there are variables to consider such as what gear the car was pulled in, tires, correction factor. Those factors alone can account for 20-40whp in either direction. ADM performance posted data of similar results in the past. They needed the LPE pump to get to 675-680whp, but the LT4 fuel system was limited to 620whp @ E60 on their in house builds.

We know the stock LT1 fuel system will not keep up on E85 with any boost.. We know the LT4 fuel system adds around 100whp of fuel system headroom over the LT1. So 580ish whp on full pump E with LT4 fuel parts. Drop back to E60 and that will extend out quite a bit.

When you tested your SS back in 2018 with the Whipple, you posted results of 616whp @ 9psi on E60. Just curious why didn't you post any results of higher E content at the same pulley? When I spoke with you back then you made it sound like that you could not run a higher blend of E that is why you posted the results on E60. That is also why I purchased the LPE HPFP which allowed me to run pump E without mixing @ 8psi but I was near the fuel systems limits.


So aside from dyno numbers this has been my findings on my own personal car.

-LT4 injectors, LPE HPFP, LT4 low side with JMS. Was able to run E82 @ 8psi with a Rotofab, 95mm tb, and cat deletes. .82 lambda 20 degrees of timing. Injector MS 5.9-6.0ms, high/low pressures holding.

-Swapped to Rotofab big gulp and 3.375 pulley and ran out of fuel. Had to drop back to E60. .82 lambda, 19 degrees timing, 5.9-6.0 IPW.

-3.25 pulley and 103 tb. Ran out of fuel again, had to drop back E40. 18 degrees of timing, .82 , same IPW.


I would be curious to see some of your data on stock cam LT1 cars with boost running blends of E and mods.

I agree the LT1 makes more power per psi due to the compression increase but the pistons rings likely will not survive long running leaner then .82. The LT4 engine can be ran leaner...I have read you and others cite running them around .84. Therefor the larger fuel lobe and leaner mixture should be able to go a little further then the LT1. Now if you run them both at the same AFR then yea I agree.

Either way I will continue to do my own R&D and go with what I find works. The OP is free to chose his own path that he is comfortable with.

As always great info!! Thank you!

I have decided to install the LPE for now and hold off on installing the +30’s. Gonna see how it plays out.

I just got the car fired up and did a few logs of normal driving, my tuner has sent a few revisions and we are ready to start doing some small wot pulls. However I’m in Mi and it started snowing and the temps are dropping into high 20’s from high 40’s today so it might be a bit. Once we get it 95% I’m gonna schedule some dyno time.

Who knows I might just put the +30’s in soon not 100% yet. I will keep it updated as I progress.

Thanks again for all the great info guys!!

[JANNETTYRACING]

Originally Posted by KingLT1

No sir I am not confused...I can go back to 2017-2019 and bring up posts that we have taken part in where it has pretty much been stated several times that 620whp is where a stock cam LT1 maxes the LT4 fuel system @ E60. That isn't a hard number buy any means.. there are variables to consider such as what gear the car was pulled in, tires, correction factor. Those factors alone can account for 20-40whp in either direction. ADM performance posted data of similar results in the past. They needed the LPE pump to get to 675-680whp, but the LT4 fuel system was limited to 620whp @ E60 on their in house builds.

We know the stock LT1 fuel system will not keep up on E85 with any boost.. We know the LT4 fuel system adds around 100whp of fuel system headroom over the LT1. So 580ish whp on full pump E with LT4 fuel parts. Drop back to E60 and that will extend out quite a bit.

When you tested your SS back in 2018 with the Whipple, you posted results of 616whp @ 9psi on E60. Just curious why didn't you post any results of higher E content at the same pulley? When I spoke with you back then you made it sound like that you could not run a higher blend of E that is why you posted the results on E60. That is also why I purchased the LPE HPFP which allowed me to run pump E without mixing @ 8psi but I was near the fuel systems limits.


So aside from dyno numbers this has been my findings on my own personal car.

-LT4 injectors, LPE HPFP, LT4 low side with JMS. Was able to run E82 @ 8psi with a Rotofab, 95mm tb, and cat deletes. .82 lambda 20 degrees of timing. Injector MS 5.9-6.0ms, high/low pressures holding.

-Swapped to Rotofab big gulp and 3.375 pulley and ran out of fuel. Had to drop back to E60. .82 lambda, 19 degrees timing, 5.9-6.0 IPW.

-3.25 pulley and 103 tb. Ran out of fuel again, had to drop back E40. 18 degrees of timing, .82 , same IPW.


I would be curious to see some of your data on stock cam LT1 cars with boost running blends of E and mods.

I agree the LT1 makes more power per psi due to the compression increase but the pistons rings likely will not survive long running leaner then .82. The LT4 engine can be ran leaner...I have read you and others cite running them around .84. Therefor the larger fuel lobe and leaner mixture should be able to go a little further then the LT1. Now if you run them both at the same AFR then yea I agree.

Either way I will continue to do my own R&D and go with what I find works. The OP is free to chose his own path that he is comfortable with.

As I recall and I could be wrong because I'm Old LOL, I think I was running .78 when I was testing my own car.

Remember is was very early, I had the first Gen6 in the northeast, and the first of the Magnuson and Whipple both on that same car.

We were thrashing collecting data and developing calibrations to get info out to you guys.

We have learned a lot since then.

I really enjoy our back and forth discussions so don't think for a minute I am not having fun.

Ted.

[JP374]

Hey guys just wanted to give you a update:

So when I ordered the kit it was spec’d at 7psi at 6500 rpm (3.9” pulley). I’ve confirmed this 3-4 times by calling PC tech. However after doing some logs with my tuner we are seeing 9.5 psi at 6500 rpm. I have the LT4 stuff with DSX aux pump, car is on 93 still and we are just starting to see high side drop but are still at 5.2 ms. I believe targeted .82 lambda. With 14* timing so far. Tuner made some changes and wants to see if high side is gonna hold before we start adding E. Tuners says we will most likely have to pulley up to 7.5-8.5 psi to be able to run a blend of e50/60.

Now it’s only been 30-40* degrees outside and I normally wouldn’t drive the car but wanted to get some data. I’m not sure how much fuel loss I’m getting vs driving it 50-60 or 80+ temps outside.

I do have the LPE HPFP and +30 inj on standby.

Can I see targeted lambda in log or tune?

I’m still learning as I go and dependent on my tuner.

Thanks JP

[cjperformance]

Originally Posted by JP374

Hey guys just wanted to give you a update:

So when I ordered the kit it was spec’d at 7psi at 6500 rpm (3.9” pulley). I’ve confirmed this 3-4 times by calling PC tech. However after doing some logs with my tuner we are seeing 9.5 psi at 6500 rpm. I have the LT4 stuff with DSX aux pump, car is on 93 still and we are just starting to see high side drop but are still at 5.2 ms. I believe targeted .82 lambda. With 14* timing so far. Tuner made some changes and wants to see if high side is gonna hold before we start adding E. Tuners says we will most likely have to pulley up to 7.5-8.5 psi to be able to run a blend of e50/60.

Now it’s only been 30-40* degrees outside and I normally wouldn’t drive the car but wanted to get some data. I’m not sure how much fuel loss I’m getting vs driving it 50-60 or 80+ temps outside.

I do have the LPE HPFP and +30 inj on standby.

Can I see targeted lambda in log or tune?

I’m still learning as I go and dependent on my tuner.

Thanks JP

Yes, I graph the commanded and actual lambda values side by side in my logs. Off-hand I'd say maybe up to 1 ms difference between running in 40 degrees vs 80 degrees F weather. In cooler weather, 50-60F even with a 4.13 pulley I'm seeing 9.5 PSI at around 6800 RPM. But it depends on so many factors. 5.2 ms on 93 seems high considering that when I run 50% E in 50 deg F I'm around 5.5 ms. I would have thought there'd be more overhead.

I'm wondering if the SOI was changed to widen the window. Not sure if inj pw changes/extends to cover the whole inj window, or if simply injects the fuel sooner, but inj pulse ms remains the same.

In other words, if the SOI is changed, with all other conditions being the same, would it affect the inj pw?

[JP374]

Ok thanks CJ, I’ll check into it more on my logs etc.

Ok So last revision he adjusted SOI and it appears my high side is dropping below the 2900 psi commanded but low side is staying at 73psi. Tuner thinks my high side is failing or shimmed wrong or I’m hitting over 700 whp and thinks that highly unlikely. It starts dropping psi at 5k rpm mark and down to 2750 ish psi at 6500rpm. I’m at 10psi at 6500 but it’s sub 30* outside. Awaiting confirmation on next steps. I have the LPE pump sitting here ready to go so we shall see.

Thanks Jp

[JP374]

Originally Posted by wnta1ss

Cold air like that (under 30) means you are making more actual hp and therefore burning more fuel. Crap my stock car run in 60 temp had an SAE of .97, so a supercharger in a temp below 30 is going to make a lot more than corrected numbers say.

Yea I kinda figured that. Makes sense with colder air etc. So I’m essential I’m probably only at 8psi in warmer temps vs 10psi now?

I’m trying to find out if the commanded high side is set at 2900psi and it’s dropping to high 2700’s at wot if that means my HPFP is bad? Tuner says it’s bad or that it’s installed wrong. My low side is holding 73 psi. I have LT4 pump and Injectors with DSX aux pump, stock cam. Tuner says the low side should drop before high side and that when the high side drops below 2900 psi the MS goes up in the window. I’m still learning all of this and just wanting to understand it better is all.

Thx

[KingLT1]

I would Wait till temps get 45 or higher then start logging. The low side doesn't necessarily always drop before the high side. If we were comparing to a stock low side then yes but you have a DSX aux pump which is more capable then your LT4 high side without meth. a couple hundred PSI drop on the high side isn't a big deal especially if your IPW's are in check. If the pressure loss is significant then it will cause the IPW's to increase. If the IPW's go above 6ms sustained then you have issues to address. If they stay under 6.2ms then you are burning fuel on time.

The main issue I see is you are running the car in temps that are too cold and really not conditions that are ideal for higher horsepower applications. No tires hook when it's that cold anyway.

All that being said it sounds like you have enough fuel for 30 degree weather on 93. Might be able to put a splash of E in it. Once you get up around 50 degrees and above fuel system headroom will increase and boost will decrease allowing you to run more E.

[JP374]

Originally Posted by KingLT1

I would Wait till temps get 45 or higher then start logging. The low side doesn't necessarily always drop before the high side. If we were comparing to a stock low side then yes but you have a DSX aux pump which is more capable then your LT4 high side. a couple hundred PSI drop on the high side isn't a big deal especially if your IPW's are in check. If the pressure loss is significant then it will cause the IPW's to increase. If the IPW's go above 6ms sustained then you have issues to address. If they stay under 6.2ms then you are burning fuel on time.

The main issue I see is you are running the car in temps that are too cold and really not conditions that are ideal for higher horsepower applications. No tires hook when it's that cold anyway.

All that being said it sounds like you have enough fuel for 30 degree weather on 93. Might be able to put a splash of E in it. Once you get up around 50 degrees and above fuel system headroom will increase and boost will decrease allowing you to run more E.

Yea I was wondering about the temps etc. I plan to hold off until warmer temps.

The IPW’s don’t go above 5.2 at highest. But after looking at log the high side moves around from 2300 psi mid pull to 2900 psi, low side stays at 73psi whole time. So there might be something going on with HPFP. Idk.

Tires definitely don’t hook in these temps, found that out from 65 roll. Tried easing into it and broke traction.

Here’s a pic of log.

[KingLT1]

Spinning will make the fuel system read all over the place due to load changes. your AFR will also read leaner in lower gears. Ideally with a A10 you want to make a single gear pull in at least 5th gear minimum...simulating a dyno. If your Rail pressure actually dropped 600psi your injector pulse would go significantly wider. 5.2 and 27% duty cycle tells me you have plenty of fuel.

[JP374]

Originally Posted by KingLT1

Spinning will make the fuel system read all over the place due to load changes. your AFR will also read leaner in lower gears. Ideally with a A10 you want to make a single gear pull in at least 5th gear minimum...simulating a dyno. If your Rail pressure actually dropped 600psi your injector pulse would go significantly wider. 5.2 and 27% duty cycle tells me you have plenty of fuel.

Ok makes sense, I definitely was spinning. Thanks King!

I will let my tuner know that as well.

[cjperformance]

Your airflow of 86 lbs/min is very high compared to my own logs, prob due to the really cold air. Most of my logs didnt exceed 80 lbs/min in 50 to 60 deg air. That actually explains a lot to me at least why your inj pw is so high for 93. More air needs more fuel. Cold air is denser air.

This all seems very in line with what i see in my own logs.

You prob mentioned this before..., but curious... if you have the injectors and higher cap pump already.... why not just install and use them? You can donate them to me if you like

[JP374]

Originally Posted by cjperformance

Your airflow of 86 lbs/min is very high compared to my own logs, prob due to the really cold air. Most of my logs didnt exceed 80 lbs/min in 50 to 60 deg air. That actually explains a lot to me at least why your inj pw is so high for 93. More air needs more fuel. Cold air is denser air.

This all seems very in line with what i see in my own logs.

You prob mentioned this before..., but curious... if you have the injectors and higher cap pump already.... why not just install and use them? You can donate them to me if you like

Yea not sure about the airflow data.

Yes, I have LT4 HPFP,injectors, DSX pump currently. I do have +30 and LPE pump nib sitting on the shelf. Probably the next step but my tuner won’t tune the car with those in it…..he highly advised me to not install those parts, not sure why.

[KingLT1]

This the same tuner we discussed via PM?