Big End Fueling SetUps

BigHemi02

BigHemi02

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Sep 1, 2011
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Who wants to give up some insight on best ways to gain more fuel on the big end of the track?

Im cutting 1.633 60' on street tires.
5x.022s, single s475 sx4, 4x4 rcsb 12v.
By 3rd gear the freight train runs clean, and I've shaved over a second off my 1/4mi buy changing my launches, but still a terrible trap speed, cause she doesnt have power up top.
Im thinking if timing is just too low? Going too high itll be a pain to spool (will NOT use power adders or compounds), but it has a looooose convertor (3200)
Has .120 billet holders and and full cuts, shell free spin to 5500rpm, dual fed, a1000 took a dump and AD150 fuels to 42psi tops.

Whats the best timing to set this at? 32-34*?
Would .120 lines help fuel delivery? (Stock lines now)
I have 2 AD165s i was gonna tru dual feed the pump, but i know a 150 is capable of lots of HP

Anyone willing to let.loose some secrets? TIA
 
What rpms are you seeing at the end?
Who did your pump? You may need some work done to it, and possibly a quick rate cam
 
Just because it free spins to 5500RPM doesn't mean it has fuel up there...My old truck with a 5K kit would pull all the way up to about 51-5200RPM on the dyno, but still made it's peak power about 38-3900RPM like most trucks...

What gearing do you have that you need it to pull past 5K when your truck probably makes best power below 4K, and what speed are you trapping that you run out of RPM??

That same truck of mine I had to 138mph once on a LONG stretch of road, which is ~3600rpm with an auto and 3.55's...it takes a TON of power to do that in the 1/4...

Chris
 
Im hitting OD about 1000' and crossing around 4200, she peaks on tach recall at 4500. The pump is a 2nd hand pump that was supposedly flowed to 600cc, specs unknown. I put in the DVs, hold my beer springs were already in it.

Id like to pull the pump and have it sent to get her maxed out as it's a dedicated race truck, and put it to my specs, but i dont know where.to send it to thats worth a damn.

I also think theres a bit.more i can do to get more fuel up.top with my set up my changing external fueling or timing in the mean time.
 
Signature600 said:
Just because it free spins to 5500RPM doesn't mean it has fuel up there...My old truck with a 5K kit would pull all the way up to about 51-5200RPM on the dyno, but still made it's peak power about 38-3900RPM like most trucks...

What gearing do you have that you need it to pull past 5K when your truck probably makes best power below 4K, and what speed are you trapping that you run out of RPM??

That same truck of mine I had to 138mph once on a LONG stretch of road, which is ~3600rpm with an auto and 3.55's...it takes a TON of power to do that in the 1/4...

Chris
Click to expand...
I agree, i think shes defueling around 4100 at most, prolly defueling around 3700, its hard ro pay attention, lol. Truck was trapping 110 on a smaller charger with 2.1 60", buy 105 with the 75mm and 1.6 60', dont make sense lol

And truck has 3.73s
 
You shouldn't be anywhere near 4200RPM at 110mph?? Assuming a 32" tire, you should be at 2800-3000RPM in 4th at 110mph.

3rd gear locked at 110mph would put you at 4200RPM...

What rubber are you running?


I also never had any luck with Hold my beer springs from down south, I know a lot of people run them, but mine never ran right. Had to sell that pump and get a pump from Columbus Diesel.

Chris
 
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Signature600 said:
You shouldn't be anywhere near 4200RPM at 110mph??

What rubber are you running?

Chris
Click to expand...

That was before, sorry, i dont remember the rpm when she was doing 110, with 9 guages, i pay attention to none of them, ill behonest, lol
 
BigHemi02 said:
Im hitting OD about 1000' and crossing around 4200, she peaks on tach recall at 4500. The pump is a 2nd hand pump that was supposedly flowed to 600cc, specs unknown. I put in the DVs, hold my beer springs were already in it.

Id like to pull the pump and have it sent to get her maxed out as it's a dedicated race truck, and put it to my specs, but i dont know where.to send it to thats worth a damn.

I also think theres a bit.more i can do to get more fuel up.top with my set up my changing external fueling or timing in the mean time.
Click to expand...

Send the pump to Farrel diesel service. Hands down best pump guy in the states. Get that aeromotive going again and keep it at 60 psi.
 
BigHemi02 said:
Its a light haze after maybe 4-500', timing is at 25 now
Click to expand...

I would think that is a good balance of bottom end to spool a S475, and top end. I really can't think going to 30+ will magically solve it, I would think you might trap faster, but lose it on the bottom end.

My first thoughts are to see if fuel pressure is holding, if so, then there may be some more tuning to do..

Do you run a fuel plate? What AFC mods have you made?

If fuel pressure is holding, then a S475 should NEVER clean up a real 600cc...My pump was set at 450cc (turned all the way down) and a 71mm and spray didn't come close to cleaning up, running a 12.08 @ 108mph.

I would bet against you having a real 600cc...that's harder to do with a 12mm than most pump shops will admit from what I understand.
Chris
 
Signature600 said:
You shouldn't be anywhere near 4200RPM at 110mph?? Assuming a 32" tire, you should be at 2800-3000RPM in 4th at 110mph.

3rd gear locked at 110mph would put you at 4200RPM...

What rubber are you running?


I also never had any luck with Hold my beer springs from down south, I know a lot of people run them, but mine never ran right. Had to sell that pump and get a pump from Columbus Diesel.

Chris
Click to expand...

And i just checked, gears are 3.54, good guess on the tire too, lol 32 (305/50/20)
And the springs have been really good to me. Again, they were in the pump when i got it, so either there HMB springs, but the fact they run smooth and trouble free, i wonder if there not CDS springs, as i hear hold my beer springs go up to like 5800 or something??
 
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Signature600 said:
I would think that is a good balance of bottom end to spool a S475, and top end. I really can't think going to 30+ will magically solve it, I would think you might trap faster, but lose it on the bottom end.

My first thoughts are to see if fuel pressure is holding, if so, then there may be some more tuning to do..

Do you run a fuel plate? What AFC mods have you made?

If fuel pressure is holding, then a S475 should NEVER clean up a real 600cc...My pump was set at 450cc (turned all the way down) and a 71mm and spray didn't come close to cleaning up, running a 12.08 @ 108mph.

I would bet against you having a real 600cc...that's harder to do with a 12mm than most pump shops will admit from what I understand.
Chris
Click to expand...

Im thinking the same thing. I need to send this pump off. She spools in about 6 seconds bumpin in (i run P/T), and (get ready to laugh) this is a stock block, stock HG, stock cam, 300k plus miles. I have a hamilton 188/220 and 1.45 tappets to go in one day, so with bumping the timing up, i still be around that 5-6 second spool range.

No fuel plate, i was running an industrial injection fuel plate with the AFC delete, but that's more.pullin stuff.
I went to no plate, and worked the AFC to more travel, but im.wondering if i just didnt work it enough and the gov arm is holding back its potential, like i need to grind the foot more
 
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Another hard part is, my local track only runs T/T om friday, and only 630-9 (after 9 is drag radials and slicks only) so i dont have a huge window to play. If i can even get out there, and it doesnt rain (which is usually does in south florida) the street fighter kids break alot of stuff, and the big tire guys are still allowed to run with us street tire guys, and they burn a LOT of time. So i only get a handful of runs a year really.

I live on a dirt road and theres litterally no back roads i can test on, cause theres 3 million people in this county, so im trying to guesstimate where to dial this truck im at before i get there.

And my dyno guy wont let me run anymore cause i smoke the shop out all over his 100k+ cars, and the other dynos here are garbage dynos that.wont give me.real numbers, lol
 
BigHemi02 said:
And i just checked, gears are 3.54, good guess on the tire too, lol 32 (305/50/20)
And the springs have been really good to me. Again, they were in the pump when i got it, so either there HMB springs, but the fact they run smooth and trouble free, i wonder if there not CDS springs, as i hear hold my beer springs go up to like 5800 or something??
Click to expand...

I had CDS springs...I liked them WAY better than the hold my beer, and they PULLED and ran smooth as glass.

BigHemi02 said:
Im thinking the same thing. I need to send this pump off. She spools in about 6 seconds bumpin in (i run P/T), and (get ready to laugh) this is a stock block, stock HG, stock cam, 300k plus miles. I have a hamilton 188/220 and 1.45 tappets to go in one day, so with bumping the timing up, i still be around that 5-6 second spool range.

No fuel plate, i was running an industrial injection fuel plate with the AFC delete, but that's more.pullin stuff.
I went to no plate, and worked the AFC to more travel, but im.wondering if i just didnt work it enough and the gov arm is holding back its potential, like i need to grind the foot more
Click to expand...


That would be my thoughts, is maybe pull the AFC foot and make a few passes and see if there is any change...then you know you need to work some more travel in there...
Chris
 
Thanks, i think ill run this friday, timing up to 28* and yank around with the AFC and mount my go pro on my guages so i can hillbilly data log, lol
 
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