dual quad nitrous !!?!!

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justinp61 said:
j par said:
justinp61 said:
What rpm are you shifting? How is the 60' after the ss springs compared to before? Did you loosen the front end up? Have you tried different fuels? My 434 made 30 more HP and 25 ftlbs of torque on the dyno with pump 93 over Renegade Crate 98 race gas. No jet changes, no timing changes, nothing except the gas. Plus the timing and jets were tuned for the 98.

IMO unless your iron heads are very good anything past 55-5800 rpms is just wearing out your engine. It would be interesting to see what it would do with a Victor and a 950HP.

My old 340 ran 7.24/11.60 at 3240 pounds on pump 93 and a hydraulic cam, but it had ported Edelbrocks. I think there was more in it with a better fuel system as it was laying down on the big end.

Yes, I think there is more in your car, it's just going to take a bunch of testing to find it. I don't know if there is .3 or not but with some chassis and engine tuning, experimenting with shift rpm .15 shouldn't be real hard.

I understand working with what you have and making do with what's on hand, it's what hot rodding is all about. I'm stubborn and my own worst enemy a lot of times but I learned it's easier if I listen to guys who have been down the road before. My stuff has ran pretty hard for what it is most of the time, not because of what I know. It has ran hard because I found guys who are a lot smarter than me (not hard to do) and asked lots of questions. Don't be stuck on your own ideas and too stubborn to try what someone suggests, you may be surprised what you find. The old saying, "the devil is in the details", it's true
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you've asked some good questions and given some good advice. Let me see if I can answer- shifting @ adout 6100. 60 foot has gotten a little better and I think with some more practice it will improve more ( which seems to personify down the track). Yes, loosened front and seems to get some weight transfer. Never tried different fuels, but I've been wondering? 5800 seems to be it's peek. It seems the cam wants to keep goin LOL, but I know better. Agreed, a single 4 barrel would likely be faster and an automatic for that matter, but that takes away my dream car. I've tried my best to listen to those who've been there before and there's been many. I've used quite a few examples in this situation before or people especially on the Forum have a lot of good suggestions and I'd love to follow every last one of them, but alas this is an impossibility. I try and take everybody's help that they've spent their time trying to give and put it all in the potluck table. A good example is the one you're giving here is trying a different fuel at the worst I'll just have to pull it out into a different car. It might work and it will cost even less to try a lower octane. Thank you ....
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My Demon with a stock stroke 360 around 12-1 compression, ported J heads, 750 Holley, Hughes Engines solid cam, 4.88 gears, 8 in PTC convertor with completely stock interior bench seat and no roll bar. Weighed at least 3450 lbs with me in it ran a best of 6.99. I think that is 11.teens. It ran a best of 6.47 (10.20's ) on a 100 shot of nitrous. Driven to track.
As light as your car is and it being a 410 ci. you should have a lot more ET to pick up.

View attachment Demon 2 001.jpg
 
D-50394 said:
My Demon with a stock stroke 360 around 12-1 compression, ported J heads, 750 Holley, Hughes Engines solid cam, 4.88 gears, 8 in PTC convertor with completely stock interior bench seat and no roll bar. Weighed at least 3450 lbs with me in it ran a best of 6.99. I think that is 11.teens. It ran a best of 6.47 (10.20's ) on a 100 shot of nitrous. Driven to track.
As light as your car is and it being a 410 ci. you should have a lot more ET to pick up.
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How did you go 11teens with no roll bar?
 
I answered the OP question before...

You need a fuel system that can handle the carbs and the plate simultaneously, with two different operating pressures. Sometimes it means you need a separate system or it's easier. However the smaller systems are set up to run with a stock type system. So really, you need some fuel gages and regulators and some time to set things up right.

You need to learn how to tune - especially in regard to timing settings. Then follow the kit manufacturer's instructions for your system output.

You may need to replace your spark plugs with something cooler.

You need to buy the bottle venting kit.

You need the steel mounting brackets for the bottle.

I would advise having at least two spare bottles.
 
I have raced at 8 different tracks and no one says anything about it. I run 6.20's (9.80's) now in my D50 and nobody ever looks at it. NHRA does not own any tracks in my area.
 
D-50394 said:
I have raced at 8 different tracks and no one says anything about it. I run 6.20's (9.80's) now in my D50 and nobody ever looks at it. NHRA does not own any tracks in my area.
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Must be the non NHRA deal.

Good for you. I think the rules are too tight in that area anyway.
 
moper said:
I answered the OP question before...

You need a fuel system that can handle the carbs and the plate simultaneously, with two different operating pressures. Sometimes it means you need a separate system or it's easier. However the smaller systems are set up to run with a stock type system. So really, you need some fuel gages and regulators and some time to set things up right.

You need to learn how to tune - especially in regard to timing settings. Then follow the kit manufacturer's instructions for your system output.

You may need to replace your spark plugs with something cooler.

You need to buy the bottle venting kit.

You need the steel mounting brackets for the bottle.

I would advise having at least two spare bottles.
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I heard you answer me before and a few posts back I was just trying to get everybody back on track sometimes things get a little sideways. And now that you bring up spark plug heat range again I had extremely hot plugs last year and when I took my head's in this winter, the Machine Shop was like those are way too hot we're going to give you some colder plugs to use. They gave me autolite 3934's . They are side Gap plugs that are gapped at 45 right now with the New MSD ignition. It's hard to say I can tell any difference because of all the changes I've made. I seem to be running at about 33-34 all in for timing. Last year I was running about 34 all in timing and I was getting a little pre ignition which I could tell on the top of the Pistons when I took the heads off it wasn't terrible or anything but it was noticeable. I was kind of thinking it was the hot plugs. At this point I just need to get a lot of consistent passes so I can make small changes and see what makes the difference timing, plugs, jets, and carburetor that kind of stuff. For the rest of the season I think I'm not gonna try and Chase 1 or 2 tenths. if that's all I can get out of the car, I'd rather dial it back a couple tenths and just be consistent and not break anything.
 
Side gapped plugs? I'd rather see std tip but regardless in either case they should be indexed. Indexing will get you more power than side gapping.
 
j par said:
I heard you answer me before and a few posts back I was just trying to get everybody back on track sometimes things get a little sideways. And now that you bring up spark plug heat range again I had extremely hot plugs last year and when I took my head's in this winter, the Machine Shop was like those are way too hot we're going to give you some colder plugs to use. They gave me autolite 3934's . They are side Gap plugs that are gapped at 45 right now with the New MSD ignition. It's hard to say I can tell any difference because of all the changes I've made. I seem to be running at about 33-34 all in for timing. Last year I was running about 34 all in timing and I was getting a little pre ignition which I could tell on the top of the Pistons when I took the heads off it wasn't terrible or anything but it was noticeable. I was kind of thinking it was the hot plugs. At this point I just need to get a lot of consistent passes so I can make small changes and see what makes the difference timing, plugs, jets, and carburetor that kind of stuff. For the rest of the season I think I'm not gonna try and Chase 1 or 2 tenths. if that's all I can get out of the car, I'd rather dial it back a couple tenths and just be consistent and not break anything.
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I hate to be a pisser but you do NOT have a side gap plug. The plug you are using has a cut back ground wire. That is not a side gap.

We need to use the correct nomenclature or everyone will be saying something different. What you are saying (and some people are construing) is you are using a RETRACTED GAP plug. That would be equivalent to a Champion N57R or similar.

Just want to clear that up. You are using a plug with a cut back ground strap. Back in the day, we used to cut them off ourselves. Results were iffy at best. There is very little HP in the center wires, ground straps and all that stuff. The HP comes first and foremost from the correct STYLE of plug and heat range. Other than that, it is picking the fly poop out of the pepper.
 
Would someone please explain these terms to me!

Side gap?

RETRACTED GAP????

What is the advantage/disadvantage?
 
Yeah - that's a cut background strap. I've always called them side-gapped but tomato tomahto. If you look at a plug for a rotary it's pribably a real side gapped plug vs cut back...
Sparks jump best off corners - and the cut back ones jump better and the thought is the spark is hotter as a result. There are all kinds of opinions on whether that's a benefit or not. I tend to believe that the flame kernel that forms, should start at the open side of the electrode and expand outward towards the exh valve without having to go around the strap. I've found that indexing to ensure this happens can yield enough of a boost to show up on a time slip. A friend used to use a special set in his car to back up record runs... But we're really talking minutia here and with multi-spark and high powered ignitions now in use there's not that much to be found there.
 
moper said:
Yeah - that's a cut background strap. I've always called them side-gapped but ((tomato tomahto.))
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That's some mind-reading stuff! That's exactly what I was thinking when the argument was presented.
 
Cudafever said:
Would someone please explain these terms to me!

Side gap?

RETRACTED GAP????

What is the advantage/disadvantage?
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Retracted gap has the ground wire BELOW the shell of the plug. I have no idea what they were originally designed for, but I do know that some 2 strokes used them. When you have the plug very close to the piston, and you can't index enough clearance, you use a retracted plug. I still have a gapping tool for retracted gap plugs.

One of the issues is when the ground wire is down in the plug shell, they are usually very cold plugs. There is no room to make the shell longer.

What jpar is using is a cut back ground wire plug. There is also surface gap, angle gap, fine wire.

Like I said, getting the correct STYLE plug is first order, then the correct heat range. The ground wire is for picking the fly poop out of the pepper. There are many ways to get quicker time slips for way less work that dealing with spark plug ground electrodes.
 
Moper and yellow rose, thank for the explanation!

I have seen all three types, just didn't know there names
 
Jason,

A random neuron fired and it went some thing like this:
From back last June when you started this thread:

i must be completely missing something ?!? (Multi-page thread 1 2 3 4 5 ... Last Page)

Till now where you are contemplating Nitrous.

Most of your posts have centered around your own admitted lack luster performance and whats wrong. After additional port work, up sizing valves and adding 1.6 rockers in place of 1.5's, you picked up 1 mph or so. Not a real good return on investment.

The thought that came to mind is..do you know for absolute certainty that the secondaries on your carbs are opening??? May be an off the wall question; don't remember if the question has been asked in the past; didn't take the time to search thru all the reply's and posts generated so far. I be-leave it's a fair question.....your carbs are air valve secondaries, been a very long time since I've been inside one adjusting secondary opening point. If they don't open, you are only running on the primaries and your times kinda reflect only about 600 cfm worth of air in the engine. Think about it, it kinda makes sense, as you did not pick up hardly any mile an hour after your winter building spree. Your combination should lay down much better mph numbers.........I mean the basic pieces are there! I'm not much interested in what the O2 sensor is telling you.......it could still just be telling you what your primaries are doing. Adjust your secondaries to open faster/sooner, probably bog, make it. Then slow them down. It's a tuning excersize.

Just do it.
Good luck.
 
JBurch said:
Jason,

A random neuron fired and it went some thing like this:
From back last June when you started this thread:

i must be completely missing something ?!? (Multi-page thread 1 2 3 4 5 ... Last Page)

Till now where you are contemplating Nitrous.

Most of your posts have centered around your own admitted lack luster performance and whats wrong. After additional port work, up sizing valves and adding 1.6 rockers in place of 1.5's, you picked up 1 mph or so. Not a real good return on investment.

The thought that came to mind is..do you know for absolute certainty that the secondaries on your carbs are opening??? May be an off the wall question; don't remember if the question has been asked in the past; didn't take the time to search thru all the reply's and posts generated so far. I be-leave it's a fair question.....your carbs are air valve secondaries, been a very long time since I've been inside one adjusting secondary opening point. If they don't open, you are only running on the primaries and your times kinda reflect only about 600 cfm worth of air in the engine. Think about it, it kinda makes sense, as you did not pick up hardly any mile an hour after your winter building spree. Your combination should lay down much better mph numbers.........I mean the basic pieces are there! I'm not much interested in what the O2 sensor is telling you.......it could still just be telling you what your primaries are doing. Adjust your secondaries to open faster/sooner, probably bog, make it. Then slow them down. It's a tuning excersize.

Just do it.
Good luck.
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Oh so now you want to bring up some old stuff! LOL just joking!
The secondaries are food for thought and I already know that Edelbrock probably aren't the best 4 drag racing anyways but it is what it is it's what I got so it's what I've had to deal with. I think the secondaries are opened up by what the motor is basically calling for. I've read a lot about dual carbs of course on the internet and I can't believe all of it but there seem to be quite a specialist talking about 2 600 CFM not being 1200 CFM but actually about 850 to 900 in the end. Explain how it didn't work that way like you would think.
I get what you're saying about the miles per hour I don't even think I picked up any of that. I had some runs better and some runs worse as far as miles per hour, but where I wanted to really pick up any rate was et.
The way I had it calculated I put another three hundred pounds or so in the car with the eight point roll bar all the fish plate the bigger Springs and the Dana vs. The eight and three quarter and frame connectors. in essence I should have slowed down 3 tenths because of the extra 3000 pounds, but I've gained 2 tense in the quarter mile which in my Twisted Brain says I picked up a half a second? And that's again apples and oranges I mean it could be discussed either way and I'm definitely not trying to argue but again just trying to point out how it came to be in my Twisted Brain. I seem to still be moving forward which is a good thing. from the car I brought home two years ago I'm feeling pretty good. In the end I will see what I can do about making sure the secondaries are opening. I'm not exactly sure how to test that?? thank you for the insight. And ideas....
 
eddy carbs,....

low vaccum, high rise...

It may be worth lookin into.

remove the hats, and goose the girl HARD..
watch and see if your pulling enough vaccum to open the secondary. if not adjust the spring.
 
j par said:
Oh so now you want to bring up some old stuff! LOL just joking!
The secondaries are food for thought and I already know that Edelbrock probably aren't the best 4 drag racing anyways but it is what it is it's what I got so it's what I've had to deal with. I think the secondaries are opened up by what the motor is basically calling for. I've read a lot about dual carbs of course on the internet and I can't believe all of it but there seem to be quite a specialist talking about 2 600 CFM not being 1200 CFM but actually about 850 to 900 in the end. Explain how it didn't work that way like you would think.
I get what you're saying about the miles per hour I don't even think I picked up any of that. I had some runs better and some runs worse as far as miles per hour, but where I wanted to really pick up any rate was et.
The way I had it calculated I put another three hundred pounds or so in the car with the eight point roll bar all the fish plate the bigger Springs and the Dana vs. The eight and three quarter and frame connectors. in essence I should have slowed down 3 tenths because of the extra 3000 pounds, but I've gained 2 tense in the quarter mile which in my Twisted Brain says I picked up a half a second? And that's again apples and oranges I mean it could be discussed either way and I'm definitely not trying to argue but again just trying to point out how it came to be in my Twisted Brain. I seem to still be moving forward which is a good thing. from the car I brought home two years ago I'm feeling pretty good. In the end I will see what I can do about making sure the secondaries are opening. I'm not exactly sure how to test that?? thank you for the insight. And ideas....
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FWIW MPH is HORSEPOWER, ET is HOOK. The two go together. If you increase HP the MPH must go up.


An example: 12.00 at 140 MPH shows you didn't hook but made HP. The opposite is true as well. A 12.00 at 88 MPH says you are hooking like you are on cogs, but you didn't make any HORSEPOWER. Or, you are a giant sandbagged. ET and MPH go together.

Also interesting is the simple fact that ALL power/speed calculators use HORSEPOWER and NEVER use torque to calculate ET. If they do, they are useless and not accurate. That's why we have transmissions and differentials.
 
have you used a vaccum gauge hooked to the base of the carbs?

you should be able to correlate that to the spring your carbs want.

Vaccum at the carb is your friend. its old school but it dont lie.
 
Vacuum isn't what opens the secondary's, if Velocity. A vacuum gauge won't tell you much on that side.

start in 3d or high gear(light throttle) around 3000 rpm and whack the throttle. stay in it until you hit your shift point.
Loosen air door/s screw 1/2 of a turn and try it again. When it finally bogs off the hit, turn back 1/4 of a turn and test again.

It is vary possible that them air doors are not opening or not all the way.

Good thought JBurch!!!!
 
Edelbrock carbs are ok, basically new copys of Carter AVS's with a few updates. People been going fast with them for years. It's what you've got, work with it, make it work!

In your vid "Bye-Bye ricer" it kinda looks like you are still hopping down the track at launch, go to a tighter shock setting, slow the body rise down just a little; that should help 60ft and out to the big end.

Good luck, let us know how it goes.

We want vids!!!!!!
 
Seems the duster is getting quicker every time out. Good size crowd for how it is now. Back to hopping at launch again. My first thought is the rear shocks are topping out (not long enough). no bog, but that could be the slippery track. I was leaving at a higher rpm, don't ask me what that is rrrrrrrr instead of rrrrr. LOL
I had a LOT of fun and came home safe.
View attachment 20160416_221318.jpg
 
Good light!

MPH says there's high 10's in the car, and it all in the chassis; adjust as needed to find it.

Shocks could be going full extension, however, slowing body rise down would make it happen later and be less noticeable IF and WHEN it occurs.
 
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