RPM's@the Stripe

Iowa 409 Guy

Well Seasoned Member
Supporting Member 15
Thanks for all the reply's guys. Here's a few answers. Running 3:17 1st gear, car weighs 4,240#, 2 Eddy 500's.... I put a cold air induction set up from Jim Sullivan (nice) before going to a spring T&T. It was cool out and I ran right on the fastest time from the past. Next time out...way rich (warmer weather?) I was out 5 times last year and am still messing with jetting. Running about the same as before the new induction. I didn't get many runs in for tuning at Bowling Green, National Trails, and raind out at a race in October. Still at it. Haven't gained much with the cold air induction yet. I figured I should pick up a tenth??? What you say??and that would put me up against 11:50 and the roll bar rule. If I go with McQuillin intake I believe I will have to go to a fiberglass hood and scoop for clearance. I had to trim some bracing out of my stock hood to clear the induction now. Also, I would have to have Jim re-do the carb spacing for the McQuillin as it Is different than my Eddy intake. Looks like I need to educate myself more on tuning these carbs, or maybe go to 600's. Is my thinking correct that I can get plenty of gas through the 500's but maybe not enough air to utilize that gas, and need to go with 600's?

EDIT...btw..I've only been changing the primary jetting.
 
Last edited:

La Hot Rods

Well Seasoned Member
Supporting Member 15
Dave I am running 2 625 cfm on this old standard bore and stroke engine.
I think with the cold air system you have it may be causing to much restriction.
I don't remember how big your engine is.
 

Fathead Racing

Well Known Member
Supporting Member 7
Dave, I run best 11.58@115. Going through the big end with 28" tire, 4:56 gear and 1:1 trans gear @ 6000 rpm showing on the tach. That's with a 3800 stall converter. I do not know how accurate the tach is. I have two 600 cfm Carter competition series carbs sitting on an Eddy intake, 474 ci.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
I always thought,based on eariler posts,that you ran 4.30's ,Ray.With your tire,115 mph works out to 5934 ,4.56's work out to 6292.8.Neither take into account tire growth,or ,in your case,converter slip.
 

Fathead Racing

Well Known Member
Supporting Member 7
I always thought,based on eariler posts,that you ran 4.30's ,Ray.With your tire,115 mph works out to 5934 ,4.56's work out to 6292.8.Neither take into account tire growth,or ,in your case,converter slip.
Yeah Don, that has always been my calculated rpm @ 115 mph with my setup also, around 6300 rpm. Looked at the tach going past the strip couple years ago at Columbus and was surprised to see the tach around 6000 rpm. I could have misread a bit, lots going on at the time. I am planing on an upgrade tach this year sometime. On a side note. I've been working on setting up the BWR heads for this year with a new set of Beehive springs (last time for Beehives) and have ran into more than one roadblock regarding spring height measurement. Just this morning I ordered a Comp Cams height mic designed for Beehive retainers only. My conventional height mic just wouldn't cut it. Tried various methods to get height but was not satisfied with the results. I will check the Comp height gauge against snap gauge then vernier's and if it checks out I can set up both heads in less than two hours.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
What have you found against bee hives,other than special tools required to set them up.Just curious.I could learn something here.
 

Fathead Racing

Well Known Member
Supporting Member 7
What have you found against bee hives,other than special tools required to set them up.Just curious.I could learn something here.
Nothing bad Don. Just newer and better thing out there now, maybe. Conical springs are now the cats ass . I chose the Beehives for lots of reasons, number one, easy on the valve train. Not any good for high rpm full race. I think they will control the valve up to 7000 rpm. Designed for hydraulic rollers, I run them on solids.
 

chevytaylor

Well Known Member
Supporting Member 2
Thanks for all the reply's guys. Here's a few answers. Running 3:17 1st gear, car weighs 4,240#, 2 Eddy 500's.... I put a cold air induction set up from Jim Sullivan (nice) before going to a spring T&T. It was cool out and I ran right on the fastest time from the past. Next time out...way rich (warmer weather?) I was out 5 times last year and am still messing with jetting. Running about the same as before the new induction. I didn't get many runs in for tuning at Bowling Green, National Trails, and raind out at a race in October. Still at it. Haven't gained much with the cold air induction yet. I figured I should pick up a tenth??? What you say??and that would put me up against 11:50 and the roll bar rule. If I go with McQuillin intake I believe I will have to go to a fiberglass hood and scoop for clearance. I had to trim some bracing out of my stock hood to clear the induction now. Also, I would have to have Jim re-do the carb spacing for the McQuillin as it Is different than my Eddy intake. Looks like I need to educate myself more on tuning these carbs, or maybe go to 600's. Is my thinking correct that I can get plenty of gas through the 500's but maybe not enough air to utilize that gas, and need to go with 600's?

EDIT...btw..I've only been changing the primary jetting.

Dave, seems your engine is making some good power with 4240lb's to push.:beer I'm no expert but this is my take on it and hope it helps.
I think the 600's would be the go, especially with the new CM intake.
I would highly recommend an air fuel gauge with the fitting connected to either left or right header collector. It'll make tuning the carb jetting allot simpler. I've jetted for around 12.7:1-13:1 through the finish line. It's a little fat but won't burn things up.
I've found that bonnet scoops do work, cool or fresh air to the carbs makes a difference. I've played around with a few different set ups but basically found that a front facing scoop works best. The cowl scoop works, but in a drag racing situation front facing is best for the ram air effect. Another thing that will help allot is a tray on top of the carbs sealed off to the scoop.
The shift point is also important. Maybe try and short shift and see what happens. With those low rear gears 28" tire and 474 inches you wont have to zing it to the moon to get into top gear and let her wind out in the deep end. The sooner you get into top gear the better, use the torque, not necessarily rpm to get there.
Anyway, not all will agree but it works for me. For example, approx 4000lb race weight, N/A, I shifted @ 5600 and crossed the finish line @ approx 6000 depending on DA. The best car has gone N/A is 11.00's @ 120+ mph in the past @ approx just above sea level DA. It mostly ran 11.1's-11.20's @ 119-120mph with an average DA of 1500'-2000' DA.
I'll try and dig out some pix of the tray and scoop set up if you like.
This is the air fuel gauge I use.
http://www.innovatemotorsports.com/products/mtxl_plus.php
 
Last edited:

Fathead Racing

Well Known Member
Supporting Member 7
Dave, seems your engine is making some good power with 4240lb's to push.:beer I'm no expert but this is my take on it and hope it helps.
I think the 600's would be the go, especially with the new CM intake.
I would highly recommend an air fuel gauge with the fitting connected to either left or right header collector. It'll make tuning the carb jetting allot simpler. I've jetted for around 12.7:1-13:1 through the finish line. It's a little fat but won't burn things up.
I've found that bonnet scoops do work, cool or fresh air to the carbs makes a difference. I've played around with a few different set ups but basically found that a front facing scoop works best. The cowl scoop works, but in a drag racing situation front facing is best for the ram air effect. Another thing that will help allot is a tray on top of the carbs sealed of to the scoop.
The shift point is also important. Maybe try and short shift and see what happens. With those low rear gears 28" tire and 474 inches you wont have to zing it to the moon to get into top gear and let her wind out in the deep end. The sooner you get into top gear the better, use the torque, not necessarily rpm to get there.
Anyway, not all will agree but it works for me. For example, approx 4000lb race weight, N/A, I shifted @ 5600 and crossed the finish line @ approx 6000 depending on DA. The best car has gone is 11.00's @ 120+ mph in the past @ approx just above sea level DA. It mostly ran 11.1's-11.20's @ 119-120mph with an average DA of 1500'-2000' DA.
I'll try and dig out some pix of the tray and scoop set up if you like.
This is the air fuel gauge I use.
http://www.innovatemotorsports.com/products/mtxl_plus.php
I've been watching you for a long time. I've learned things.
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
How are your headers set up.
The correct collector would be a must.
All the older racers would say spray paint the collector say two feet down it length of it with lacquer paint....then run the car hard then look and see how far the paint burnt off and that is where you cut the collector off.
On my charger I had some pipes that where 4 feet long or longer ( it was what I had laying around ) this car ran consistent 102 mph.
So for a try I changed the collectors to some that were 9 inches long and the car picked up to 105 mph. :good
 

La Hot Rods

Well Seasoned Member
Supporting Member 15
I also did the poor mans cowl induction and the car picked up 3 10th
Used a road sign and the bottom out of a ford truck air breather.
When you make a pan or even the bottom of your air breather needs to have the right shape to it.
It needs to blend in smooth and not have sharp or hard corners where it meet the choke horn on the carburetors.
20150612_180314 (1).jpg
20150612_180832 (1).jpg
Adjusted the hood so the back propped up and cut the foam out of some dodge van seats.
When I would these tricks I would just generally do the one for a weekend that would give me time to hone it in and sometimes it would take longer.
 

chevytaylor

Well Known Member
Supporting Member 2
Here's a couple of different ways I've tried to get the cool air to the carbs over the years Dave, ...................


. Air ducts from head lights, inline 2 x 4. Worked really well but went to cross ram.
. Cowl induction.111.jpgAt the drags.jpgDSC_1557.jpgcross ram 4.JPGDSC00313.JPGDSC02714.JPGNumber 1.jpg
. Cowl with two scoops, cross ram.
. Cowl with front facing scoop on top, worked the best.

I'm on a bit of a break at the moment, got some time to kill lol.

Hope this helps.
 

Iowa 409 Guy

Well Seasoned Member
Supporting Member 15
That cross ram looks really unique staggered on the hood. Beautiful car you have there Carl. My inlets are on each side of the radiator, same effect as using headlights, and possibly a little more pressure on the big end. I would think there is more push towards the middle than the outside of the car. Then again, I've have a few theories that were completely FOS.
 
Last edited:

Jim Sullivan

Well Known Member
Supporting Member 10
Dave, just throwing this out there, did you ever check the plugs after a test and tune run, to see how if you're rich or lean at wot? I don't know if you'd be allowed to pull a plug on the return road or not.:dunno2
 
Top