FrontEngineDragsters.Org Forum
Drag Racing Discussions => Front Engine Dragsters => Topic started by: wideopen231 on October 28, 2019, 04:37:07 PM
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Anyone have any data on how much quicker wheel speed is or isn't,if you stage lower and give engine a run at tires. In other words let it get running up to stall more should give hard hit in theory which we all know how that works out some times. Its done some in pro mods with auto and thinking it might help get wheel speed up quicker on bracket deal also in case of shake issue.
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Chris I never had any luck leaving at a low RPM with my car but it's a small block ! Mine likes around 5800 to around 6400 !
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I figure I am going to be in same area. I was just wondering because with pro mod guys I work with we let motor get run at converter to hit tires harder.Then that is 3200 hp blower car with lot more TQ than my lil injected deal. I tried inching up and does not work. Going to throw 6000 chip in if weather ever allows more testing. Thinking next time out I am going to attack it like screen name indicated WIDEOPEN and see if they smoke or move out with no shake. Then might be these M/T's will not work or need more power,oh yea more power.hum hum hum.
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We stage my car at a dead idle. It is very violent on launch. 350 rear gear, T400 trans, Very tight 9" converter, 1.0 =60 ft. !970 Lincoln block Cj heads.
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never had a car that would consider leaving at idle. Our Top Alcohol stuff even with whipple was 6000 plus. I tried 4800,shake,5400 still some but less shake and 60' picked up .035. Going to 6200 and see. If better yet I may start lowering pressure more to gain some wheel speed. Right now not looking like anything till mid December and then probably hold off till march. Would like to put some rods in that are new and not out of my TA/D combo.Only 8 runs but then 15 was max for that setup. Just warm fuzzy feeling with some new ones and new set of isky or morel lifters.
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Never going to know until you get out and run it. depends on stall, power curve, tune up, weather etc.
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Must not be keeping up Curly. I have made some test shot(part of a thread on drr).Admittedly only 3 short,part plan and part mother nature. First leave was soft with lots of shake. Second harder with lot less but still some shake and third was decent except front end was up too much ,Lifted and stab it but figured not much to learn and shut her down. After first I raised leave,after second raised it some more. After third I did the unholy and added some weight to front. Then it got all wet and figured all I would learn was how to get it down a 1/2 mile on 1/8 ,i;e track.LOL
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I got it and only way to know is to get out there and run it. Make changes and see if it is better or worse. Most everyone else is running a rear engine four link dragster with big block Chevy and most even paint them the same but they know what it takes to make it work because everyone else has similar. Trust me ours does not respond the same as the other guys and one of those guys can not say Just put a little preload in the anti roll bar. You do not have one. You can not just make a shock setting change. You do not have shocks. Our tires and weight distribution does not work the same as those guys. None are like yours. None. Any input those guys give you most likely will not work on your car. All you can do is go out in YOUR car and make changes to see if it makes it better or worse and keep making changes until it works. Even what works on mine probably is not same on your car. But I have had to make massive changes and 18 months until I was able to get it to work good. With a FED it is a balancing act between horsepower, torque converter, weight, traction, weight distribution, Tire compound, tire pressure, correct tire stiffness, chassis stiffness or flex and more.
Data logger and good slow motion video can help you narrow down what is happening and which direction to go to fix it. I actually had to change my engine angle to make it work better among many other changes.
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Agree RED guys are useless for info.Main reason I ask questions here. I am not asking what will make my car better.I was asking what others have found with their's. Nothing more than educational info. I know some like to just change and see what happens.I like to change with expected out come. Does it always work as expected,no. Knowing what should happen will help narrow down what is working proper and what is acting stupid. I like having info from many and working knowledge of as many ideas other have tried and out come. Rarely do I ask a question that is directly related to solving a problem that is current .
Curly,
You stated you changed engine angle and other things.So now question is which one really fixed problem? Which ones had no effect? What was bases for changes? Not saying what you did is wrong.I just try to never make more than one change at a time,unless I have nothing is working right and I need to throw a hale Mary shot. Like i said I have had car out.Question posted has nothing to do with that.It was to see if other have tried making a run at converter and if so what result was.Was it any different than higher stage as far as drive shaft curve if they had data recorder. Just to get idea what to expect if I try it.
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Well raising engine up helped some it was too far down. Started working with tire pressure and that did not do much. Moving some weight back helped more and working with the tires helped a little more. I have had my battery in the nose of the car, raised engine and moved battery to the rear, those two things helped and it hooked up better but was pulling big wheelies. Put battery in nose again and it stopped the wheelies but was still not working back tires right. Put the battery in the middle and now working with tires to get it right where I want it.
Each change has helped but there is no one thing that made it work and it is still not perfect. My altered rarely if ever had an aborted run or traction problem. My dragster has been a fight but it is getting better and data logger verified it. I suspect if car lost 100 Lbs or got 100 more HP I may have to start all over to tune it to work right. In my opinion it is a balancing act to get weight and performance just right on these things.
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For us, lower launch RPM slows RT & ET, softer hit. Car is moving while flashing
Curly, Slip joint top rail in front of motor mount. Made our fed triple slip jointed top rail 174" she is free. Like holding a longer rod the dragster is not as easy to control as the shorter rod like your altered.
We Just ran our Thanksgiving race here at LVMS two weeks ago. Over the last two day's in 9 passes with a track & tire temp from a low of 57/65 to a high of 80/90 with air temps from 48 to 72. Coldest was slowest 5.661. Fastest at 72 air temp she ran a 5.651 switching lanes.
Cars first slip in front of motor is 60" out to plant the tire. 60" is a shorter rod for inertia than the 125" altered
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I have slip joint in front of motor, in uprights to front and in top rail about 18" behind axle center line. First cpl hits they have all been locked down. Not sure which will work best and figure testing after get base to work from.All t takes is 1/4" allen wrench and 1/2" wrench to try them.I know with them loose you can raise middle 7" with front wheels on ground,not going that loose but its there. all have built in stops and bolt downs.
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Wide, front slip eats up the track. Our car arches at the motor only about 2" or so depending the situation.
The looser the chassis, the looser the launch and need to be on toes. Because as the chassis arches the steering rod is not.
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Maybe correct on steering.So far it seems not to have any effect of front wheels,reason I took to extreme when checking it.Plus steering seems to have zero bind in it. Heck I might screwed up and had rod ends in right location to help. If so it was at least 90% luck.Slip in front of motor is about same point as first rod end.
I thought when driving a FED you where always suppose to be on toes and ready to----------What was that thing.Oh yea drive the car.LOL Sorry had thousand rearend guys tell me I would have to be driving all the way down track in FED vs RED just cruising down.My reply was"xxxx I thought that was what a driver did".
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wide, try opening up your fronts first. Steering rod not affected as much because of closeness.
Said passes
Slow/cold pass humidity 37, dew 25 & BP of 28.04 with DA of 1305 ET 5.661
Fast/warm pass humidity 15, dew 12 & BP 28.10 with DA of 2606 ET 5.651
plus 22 humidity & lower BP by .06 canceled out better DA numbers. Cold track .01 slow, you'll know by the 330'
Both dead .001 to dial in run for money win & .009 against .015 pack for the win, bottom bulb bracket racing
Enjoy
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Maybe correct on steering.So far it seems not to have any effect of front wheels,reason I took to extreme when checking it.Plus steering seems to have zero bind in it. Heck I might screwed up and had rod ends in right location to help. If so it was at least 90% luck.Slip in front of motor is about same point as first rod end.
I thought when driving a FED you where always suppose to be on toes and ready to----------What was that thing.Oh yea drive the car.LOL Sorry had thousand rearend guys tell me I would have to be driving all the way down track in FED vs RED just cruising down.My reply was"xxxx I thought that was what a driver did".
My car is a home built chassis, built to 6.0 specs. 185" wheelbase, SBC, Powerglide with 1.67 low, 4.30 gear, 9 in converter that flashes to 5,500. MT 33x10.5w tires. Fuel cell, battery and fire bottle out front + about 84 lbs on the nose. It took about 10 test hits adding weight, adding tire pressure and raising the wheelie bar before we figured it out. Best results so far with 8psi. and no wheelie bar, LEAVING OFF IDLE, 1.06 sixty foot, 4.69 @143 shifting at 6,400 and lifting early. Dead straight down the lane, not much driving involved. You do need to stay on your toes though because if anything goes wrong it will happen quick. I did try leaving off the brake once but it blew the tires off and shifted/hit the rev limiter without even moving so I guess I'll be leaving off idle. All our racing here is 1/8 mile. I'm probably going to change to a 390 gear so I could run a 1/4 mile. That should soften up my launch a little and then I can go with a bigger cam, more ignition timing AND make it through the 1/4 without running out of rpm.
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One point caught my attention^^^. Cam. Wondering about torque curve for those leaving low rpm. Mine is not high revving SBC Like some of the Jr Fuel guys. Also no blower for mountain towing TQ. My power band should be 6000 to about 9000 and max tq around 6750,shift at 7500 and drop back to 6600(converter stall) with cam and crank combo I am running. Bigger bore to come will change it some as will compression increase later on.
On gear part. I have a 4.11 in it now and a 4.30 ans 3.90 on shelf for testing. Like stated early I built FED because it is cool as xxxx and will require actually driving the car more than a cookie cutter RED with 4 link and bbc. Right now its play and tweak some piece on car to make better as I should have gotten them first time. LOL