383 Build input request (E85)

General engine tech -- Drag Racing to Circle Track

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xxdabroxx
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Re: 383 Build input request (E85)

Post by xxdabroxx »

Other than cleaning them up from the previous head gaskets they are out of the box too. Old though, bought somewhere around 2002ish. The intake gasket area is cleaned up but I believe that was from the factory.
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Re: 383 Build input request (E85)

Post by bpenrod »

Awesome job!
xxdabroxx
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Re: 383 Build input request (E85)

Post by xxdabroxx »

https://www.youtube.com/watch?v=L1YoecQ1AGk

Video of the day at the track. I think I'm going to try tightening the rear shocks a bit to soften the hit on the tires but I'm not 100% sure that it needs it. I mean it's hooking now but IIRC from what I've read the tighter you can get the suspension the faster your short times will be.
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Re: 383 Build input request (E85)

Post by nitrokid60 »

Video looks good, launches appear consistent. The third side view launch at the 4:38 mark, rears appear close to wadding up. Use the pause button to closely examine your cars launch, it helps you see whats going on. One of my tricks is a wire tie on shock shaft to check ext or compression. Dave Morgan taught me a lot of useful ideas. Have fun and enjoy. Oh, fuel system set-up looks great. Same components as our '69 Barracuda that we've had for 10 seasons and no problems so your good to go. Damn, I still have a month to wait to go to the track. lol
6.50camaro
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Re: 383 Build input request (E85)

Post by 6.50camaro »

You tighten the shocks if you killing the tires at launch or getting to much body separation in the rear to fast (using up all your travel to soon. This manifests itself as getting good initial bite then losing traction 20' to 30' out). if you tighten the shocks and still kill the tires try more air in the tires. More preload on the caltracs with take away initial hit on the tires also.
Looks like you've got a good combination there . Now just some track time and tuning and you'll should be in the 10.0's. Good luck. Dan
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Re: 383 Build input request (E85)

Post by xxdabroxx »

Went back to the track this weekend. Went up 4 jets in the secondaries and 2 in the primaries. Tighted the rear shocks 2 clicks on comp/ rebound and softened the front 1 click on rebound and 2 on comp. Car picked up .050 off the trailer, I short shifted the second pass but it was a better 60' than the first.

If you watch the AFR gauge you can see it starts out close to 12.5 after the launch but leans out throughout the pass to closer to 14. (13 is straight up on the gauge) Not sure if that's something that high speed air bleeds would help or if it just needs more jets. I'm wondering if it isn't too much emulsion at high rpm? I don't have a full understanding of the air bleed side of a carb yet though. I know it adds air but can't the emulsified fuel flow easier as well?

https://youtu.be/BrVaEeSn0_Q
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Re: 383 Build input request (E85)

Post by steve cowan »

xxdabroxx wrote: Tue Apr 26, 2022 10:50 am Went back to the track this weekend. Went up 4 jets in the secondaries and 2 in the primaries. Tighted the rear shocks 2 clicks on comp/ rebound and softened the front 1 click on rebound and 2 on comp. Car picked up .050 off the trailer, I short shifted the second pass but it was a better 60' than the first.

If you watch the AFR gauge you can see it starts out close to 12.5 after the launch but leans out throughout the pass to closer to 14. (13 is straight up on the gauge) Not sure if that's something that high speed air bleeds would help or if it just needs more jets. I'm wondering if it isn't too much emulsion at high rpm? I don't have a full understanding of the air bleed side of a carb yet though. I know it adds air but can't the emulsified fuel flow easier as well?

https://youtu.be/BrVaEeSn0_Q
Dave,
You do great videos :D
Just a couple of questions
Do you buy E85 from the pump?
Do you test it?
I see you are using AFR it might be better to work of lambda .
Lambda 1.000 is approx AFR of 9.8 ish for E85.
Lambda 0.8 (20 % richer) is AFR of approx 7.8.
You may have your conversion worked out to suite yourself which is good but difficult to convert for me.
I would like to see a vacuum reading as you go into top gear as a reference as well.
steve c
"Pretty don't make power"
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Re: 383 Build input request (E85)

Post by xxdabroxx »

steve cowan wrote: Tue Apr 26, 2022 5:54 pm
xxdabroxx wrote: Tue Apr 26, 2022 10:50 am Went back to the track this weekend. Went up 4 jets in the secondaries and 2 in the primaries. Tighted the rear shocks 2 clicks on comp/ rebound and softened the front 1 click on rebound and 2 on comp. Car picked up .050 off the trailer, I short shifted the second pass but it was a better 60' than the first.

If you watch the AFR gauge you can see it starts out close to 12.5 after the launch but leans out throughout the pass to closer to 14. (13 is straight up on the gauge) Not sure if that's something that high speed air bleeds would help or if it just needs more jets. I'm wondering if it isn't too much emulsion at high rpm? I don't have a full understanding of the air bleed side of a carb yet though. I know it adds air but can't the emulsified fuel flow easier as well?

https://youtu.be/BrVaEeSn0_Q
Dave,
You do great videos :D
Just a couple of questions
Do you buy E85 from the pump?
Do you test it?
I see you are using AFR it might be better to work of lambda .
Lambda 1.000 is approx AFR of 9.8 ish for E85.
Lambda 0.8 (20 % richer) is AFR of approx 7.8.
You may have your conversion worked out to suite yourself which is good but difficult to convert for me.
I would like to see a vacuum reading as you go into top gear as a reference as well.
Thank you, i'm still learning but doing my best.

Yes I do run pump E85 but it always tests right at 85% here.

I'm using gas scale AFR meter because that's what was available that matches my current gauges. I figure all the gauge is doing putting AFR numbers to its calculations anyway so it shouldn't matter as long as I'm consistent and not mixing and matching scales.
AFRconversion.jpg
I don't have any vacuum gauges set up, I'd have to swap my spacer to something else or drill and tap my tapered spacer to get a vacuum port.

I also wonder if it couldn't be something to do with the RPM drop at the shift plus the scoop just starting to work at that speed and giving a bit of a ram air effect? The scoop isn't sealed to the carb but it is in a small opening that barely fits the air cleaner.
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Re: 383 Build input request (E85)

Post by steve cowan »

xxdabroxx wrote: Wed Apr 27, 2022 1:55 pm
steve cowan wrote: Tue Apr 26, 2022 5:54 pm
xxdabroxx wrote: Tue Apr 26, 2022 10:50 am Went back to the track this weekend. Went up 4 jets in the secondaries and 2 in the primaries. Tighted the rear shocks 2 clicks on comp/ rebound and softened the front 1 click on rebound and 2 on comp. Car picked up .050 off the trailer, I short shifted the second pass but it was a better 60' than the first.

If you watch the AFR gauge you can see it starts out close to 12.5 after the launch but leans out throughout the pass to closer to 14. (13 is straight up on the gauge) Not sure if that's something that high speed air bleeds would help or if it just needs more jets. I'm wondering if it isn't too much emulsion at high rpm? I don't have a full understanding of the air bleed side of a carb yet though. I know it adds air but can't the emulsified fuel flow easier as well?

https://youtu.be/BrVaEeSn0_Q
Dave,
You do great videos :D
Just a couple of questions
Do you buy E85 from the pump?
Do you test it?
I see you are using AFR it might be better to work of lambda .
Lambda 1.000 is approx AFR of 9.8 ish for E85.
Lambda 0.8 (20 % richer) is AFR of approx 7.8.
You may have your conversion worked out to suite yourself which is good but difficult to convert for me.
I would like to see a vacuum reading as you go into top gear as a reference as well.
Thank you, i'm still learning but doing my best.

Yes I do run pump E85 but it always tests right at 85% here.

I'm using gas scale AFR meter because that's what was available that matches my current gauges. I figure all the gauge is doing putting AFR numbers to its calculations anyway so it shouldn't matter as long as I'm consistent and not mixing and matching scales.

AFRconversion.jpg

I don't have any vacuum gauges set up, I'd have to swap my spacer to something else or drill and tap my tapered spacer to get a vacuum port.

I also wonder if it couldn't be something to do with the RPM drop at the shift plus the scoop just starting to work at that speed and giving a bit of a ram air effect? The scoop isn't sealed to the carb but it is in a small opening that barely fits the air cleaner.
Thanks for the clarification, I kinda figured you were converting which is fine and you can see it going lean up top.
A couple of things I would try and I would do 1 thing at a time.
Make sure fuel pressure is holding through the run.
I don't know your carb set up but I assume powervalve in front and blocked on the rear ?
Go up 4 pin sizes in rear and test.
Go up in size on your front PVRC jets and test.
Go a couple of sizes down in MAB on rear say 28 >26 see if the slight delay helps up top ?.
A vacuum reading in the plenum at WOT through the finish line might give you an indication if carb is to small .
My assumption as well is when carb was modified for E85 all main / angle wells were drilled to suite, because I am OCD I would disassemble carb and pin gauge and document everything.
Hopefully I have given you a couple of ideas to try.
steve c
"Pretty don't make power"
xxdabroxx
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Re: 383 Build input request (E85)

Post by xxdabroxx »

steve cowan wrote: Wed Apr 27, 2022 3:48 pm
xxdabroxx wrote: Wed Apr 27, 2022 1:55 pm
steve cowan wrote: Tue Apr 26, 2022 5:54 pm
Dave,
You do great videos :D
Just a couple of questions
Do you buy E85 from the pump?
Do you test it?
I see you are using AFR it might be better to work of lambda .
Lambda 1.000 is approx AFR of 9.8 ish for E85.
Lambda 0.8 (20 % richer) is AFR of approx 7.8.
You may have your conversion worked out to suite yourself which is good but difficult to convert for me.
I would like to see a vacuum reading as you go into top gear as a reference as well.
Thank you, i'm still learning but doing my best.

Yes I do run pump E85 but it always tests right at 85% here.

I'm using gas scale AFR meter because that's what was available that matches my current gauges. I figure all the gauge is doing putting AFR numbers to its calculations anyway so it shouldn't matter as long as I'm consistent and not mixing and matching scales.

AFRconversion.jpg

I don't have any vacuum gauges set up, I'd have to swap my spacer to something else or drill and tap my tapered spacer to get a vacuum port.

I also wonder if it couldn't be something to do with the RPM drop at the shift plus the scoop just starting to work at that speed and giving a bit of a ram air effect? The scoop isn't sealed to the carb but it is in a small opening that barely fits the air cleaner.
Thanks for the clarification, I kinda figured you were converting which is fine and you can see it going lean up top.
A couple of things I would try and I would do 1 thing at a time.
Make sure fuel pressure is holding through the run.
I don't know your carb set up but I assume powervalve in front and blocked on the rear ?
Go up 4 pin sizes in rear and test.
Go up in size on your front PVRC jets and test.
Go a couple of sizes down in MAB on rear say 28 >26 see if the slight delay helps up top ?.
A vacuum reading in the plenum at WOT through the finish line might give you an indication if carb is to small .
My assumption as well is when carb was modified for E85 all main / angle wells were drilled to suite, because I am OCD I would disassemble carb and pin gauge and document everything.
Hopefully I have given you a couple of ideas to try.
20220321_171326.jpg
Yes, powervalve in front, blocked in rear.
Primary jets are up to 80, secondaries are at 94 now. That's the only changes I've made from the build sheet so far.

When you say go up 4 pin sizes in rear what do you mean?

PVRC - Power valve restriction circuit?

MAB - Main air bleed? Would that be the high speed air bleed?
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Re: 383 Build input request (E85)

Post by xxdabroxx »

FWIW I haven't contacted Pro Systems for input post this past race. I figured I'd send them a link to the video and get their take as well but I haven't gotten around to it yet. Patrick gave me some advice after the first test session, they've been really good to work with so far.

I like to learn though and getting others thoughts often leads me down a new path of research to learn more.
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Re: 383 Build input request (E85)

Post by steve cowan »

xxdabroxx wrote: Wed Apr 27, 2022 5:54 pm FWIW I haven't contacted Pro Systems for input post this past race. I figured I'd send them a link to the video and get their take as well but I haven't gotten around to it yet. Patrick gave me some advice after the first test session, they've been really good to work with so far.

I like to learn though and getting others thoughts often leads me down a new path of research to learn more.
Good call on staying in contact with carb builder,your car runs good,sounds a little soft on shift recovery but I am only listening to a video.
You are correct on PVRC and high speed bleed.
Smaller bleed turns mains on later and bigger bleed turns on earlier so to speak.
You are running a 94 jet in the rear that measures a pin gauge size of 0.114"
If you go up 4 jet sizes to a 98 it measures 0.123" which is a increase of 8%
Just something to think about.
I can not remember correctly but I thought I remember Madbill saying years ago that a forward facing scoop only starts actually working above 140 mph as in super charging above atmospheric pressure but don't hold me to that statement 🤔
steve c
"Pretty don't make power"
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