FrontEngineDragsters.Org Forum
Drag Racing Discussions => Front Engine Dragsters => Topic started by: gtpete on January 09, 2019, 11:59:58 PM
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Hello everybody. Just to help me along with my build and give me something to look forward to. Can I make a pole of your FED weight and what 1/4 times you run. Thanks in advance Pete.
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Weight divided by ET3 (cubed) X 197.14 = HP
1650# / 343 (7x7x7) = 4.81
4.81 X 197.14 = 948 HP
Rough terms is that is how much HP is needed to move that weight 1320' in that amount of time
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I'm ok with the maths its just some real world numbers i'm after.
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My car weighs with driver 1650# and I run in 7.0Pro index class and usually hit the number. I dont have the time or money for dyno time to get HP figures, And that about how "real world" I get
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Not real world but the Wallace racing calculators have a simple calculator on their web page
Wallace Racing - 1/8th Mile ET/MPH/HP Calculator
Cheers
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Thanks DRE that's what I'm after. My 140" FED weighs ### with this much horsepower and I run these times ###. Thanks again.
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need mph and weight for HP on the dream wheel. mph is the key.
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Nobody else with the specs of their FED ??
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1800lbs w/driver 387” SBC 6.47 214mph
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4.92 @ 140 with 760 hp and 1800 lbs.
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That's some quick cars. Both 1800 lbs too. Thanks for the replies looking forward to some more :)
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We race NHRA Heritage JrFuel for 17 years same car was 200" WB when first built by Dave Tuttle in 1998, and we front half the chassis in 2011 when tried an early Hemi and went to 225", max WB for the class.
Car with driver weighs 1435 with the SBC, and 1500 with Hemi . We run mostly 7.00's in the 1/4, and 4.45's in the 1/8 at 153-155mph, and 1/4 speed is 186-190. Class limits are only pure alky, 12"wide tires , powerglide, all iron engine, stack injectors all at 3 1/2 lb per CI. Our engine location is 48" from back of engine to center of rear axle. The cars being built lately are 55-60" out. CI limit for JF is 430, we run 409 on the Hemi, and 400 on the SBC., but some teams run 387 ci SBC. One option we have in JF is we can also race NHRA Comp Elim, in A/ND [JFA] or B/ND [ JFB]
Call if you have more ??'s 805-444-4489, Jon
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2011-2013 we ran a FED with SBC. Dynos numbers were 600 +. Car and driver were 1460#. Ran low 5s with good track and air in the 1/8th.
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I would like for others in particular Jon Hayden to add front weights as I think it is critical to making these animals work. Mine was 1730 with 389 on front and simply was not hooking up. So it is back at chassis shop making a bunch of changes. We are moving weight back and changing engine angle from 2.7 down to .5 approx.
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These days Engine angle has zero affect unless you were way out of the park to begin with. Engine angle is the result of the relationship to how far the motor is out from the rear end to the front oil pan clearence. We are raising the front of the motor these days so that you dont tear up the diaper. Building a new chassis right now, motors out 55" and the crank snout is 10" of the deck, I dont care what the motor angle is
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These days Engine angle has zero affect unless you were way out of the park to begin with. Engine angle is the result of the relationship to how far the motor is out from the rear end to the front oil pan clearence. We are raising the front of the motor these days so that you dont tear up the diaper. Building a new chassis right now, motors out 55" and the crank snout is 10" of the deck, I dont care what the motor angle is
That is my thinking but part of reason I am changing engine and is to keep from tearing up pan and diaper. I really think my biggest problem is too much weight up front for my combination. Thanks,
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I would like for others in particular Jon Hayden to add front weights as I think it is critical to making these animals work. Mine was 1730 with 389 on front and simply was not hooking up. So it is back at chassis shop making a bunch of changes. We are moving weight back and changing engine angle from 2.7 down to .5 approx.
The actual weight on my car is 1795lbs with 432lbs on the nose
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Our combination: 200" FED, 365 cu. in. Blown Chrysler on alcohol. Engine level and 44" out. Weighed 1680 ready to race (1260 rear, 420 front). Ran on a 4.65 sec. 1/8th mile index. With 6-71 running 10% underdrive, we run the number @ 150mph. Same set-up ran 7.30s in 1/4 mile @ 180mph. Guess we were making around 850 hp but what was really important was tires, converter and starting line RPM. Good 60' time is
needed. Ours was around 1.10 sec. I think 140" WB is too short for a serious FED these days considering tire,engine, trans/converter/clutch technology available now.
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" Simply not hooking up" is more complicated than car weight vs front end weight. Our 1435 lb car has 320 lb front end weight.
If you are running a poweglide you may have too tight of a converter , the looser the stall, the easier it hits the tire , you might have too high a 1'st gear like 1.90-1.80, we have a 1.68 1'st gear, your engine combo could have a high torque set up, again it will hit the tire hard, you could be hitting the wheely bar and unloading the slicks, your slicks could be too old and hard. Also rim width makes a difference, we ran 10" wide on 12" wide slick [ max for our JF class] then moved to 11" rim , then again moved to 12" rim as I changed the power
And you thought you were asking an easy question ?
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Wow! Thanks for the responses! I hope this does not side track original post too much but here we go. I do have a powerglide with 1.80 gears. 4.30 rear gear and 6400 stall, shift at 7600 peak horsepower is 760 @ 7500 RPM. New 3074 MT tire 14 x 32 and it is not hitting wheelie bar. Same motor, tire, transmission and rear gear worked great in my 1800 Lbs 125 inch altered. In the new 225 inch dragster spins, hooks, spins. Front tires pop up maybe an inch then right back down. I think it needs to have enough power or weight moved that it can carry front wheels out a ways to keep rear tires planted. This car may work perfect with 300 more horsepower? I started off with 389 lbs on the front and it did not work so I moved stuff around and was able to get it to 369 on the front and it seemed to help a little but not nearly enough. So now it is chassis shop again and trying some things different. Moving battery back to back of car. Making new smaller fuel cell and moving it back maybe 6 feet. Hoping that I can get front weight down around 320 lbs much more than that would require major changes just not worth it. (Cheaper than adding 300 HP!) I am running a 5.0 1/8 mile index and the et is right but I need to make car hook consistently every time.
So here is my thinking and tell me if I am wrong. My thinking is with a 225 inch chassis (lever) it is very critical to have the power and weight right to make it work. I am also thinking with the longer chassis it needs to be lighter up front to work right unless you have a lot of power.
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Thanks for the replys guys some good info there. Especially the weights. You guys run some real quick cars. I'm hoping to get into the tens !!! Real slow by your standards. Does anybody run in the 9/10s ??
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Like Jon says not hooking up is complicated. In my experience it's hard to believe that a FED is to heavy on front end, usually it's the opposite problem.
Run 6,5 sec in 1/4 mile with 1,00 60´and a controlled but not perfect tire spin. Have try multiple tires, rims, gear ratios, transmission ratios, converters and still fighting the launch.
When my car spins to hard it´s a result of to hard first hit and planting the tire to hard which makes them spin.
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190", 4.10's and m/t 33x10.5-15's. 350 buick with a 471. when we added the 471, it went about 70* up and broke the f/end. fixed and added 30lbs up front AND w/bars. 60's around 1.3' and 9.0@147. making new brackets for 60lbs. w/bars are pain to put on and off.
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Thanks for the reply BuickFED sounds like a cool ride. Still no one with a 10 second car ??
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Thanks for the reply BuickFED sounds like a cool ride. Still no one with a 10 second car ??
1600lb car only needs 350hp to run 10.0. id think a bone stock 350 could at least make that much. throw in some convertor slip and whatever and your 10.2x?
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While it’s not a FED, my altered ran a best of 6.81 in the 1/8 mile at about 1620# with an almost stock 350 SBC and a 2100 stall convertor. That is about a 10.50 in the ¼ mile. Engine had 86,000 miles on it with a small cam (idled at 700rpm, 14” of vacuum), a high-rise and 600cfm carb. It was slow but VERY consistent:)
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Thanks for the replies guys, keep em coming. I should hope that my 351W should make between 400/450hp and as long as its not too heavy should get me down to the low tens. I would be very happy if I could run a 9:90 ;D
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don't confuse the chevy 350, which they make a ton of everything, with the buick 350, which I make or modify other parts. we may be lighter but not faster.
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My FED is 184” and weighs 1480 with a 350 Chevy, not much done to it. It runs 9.6@136. 1.3 60 ft. Still tuning on it.
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165" FED with a 327, first year running was pretty consistent at mid 9s, 140-143mph. Plan to weigh it this spring but estimate around 1650lbs. If I wasn't so green at the wheel I feel it could get into the low 9s with better reaction time and proper shifting.
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Keep em coming guys. Getting a good idea on power to rate ratios and times.
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How many people are running in the 9's ?
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1960# FED, blown sbc, est 950hp, runs 7.60s/178mph
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130" with 302 ci Windsor, single 4 barrel, points dist on pump fuel, 727 Torqueflite & 9" @ 1250lbs - 9.70/137.
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184' 377 sbc alcohol stack injection 4:30 rear 8.71 152 mph.
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190" FED, blown alcohol 411 cu.in. sb Ford, 1602 lbs. with driver. Around 800hp.
4.69 sec. @ 151mph. in the 1/8th.
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130" with 302 ci Windsor, single 4 barrel, points dist on pump fuel, 727 Torqueflite & 9" @ 1250lbs - 9.70/137.
OK, now THAT sounds like my kind of rail!!
I've always dreamed of building a 120" dragmaster or k-88 style dragster with a 302/c4/9" combo. I've literally got everything I need.
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Thanks guys keep the info coming. Rat it would be good to see a pic of your SBF rail.
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Not my car, it is the car that got me pointed me in the right direction and buying my own. It belonged to one of the brothers that I currently drive for. Sorry Picture quality is not real great.
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Not my car, it is the car that got me pointed me in the right direction and buying my own. It belonged to one of the brothers that I currently drive for. Sorry Picture quality is not real great.
Rat, is that the same Colthrups that have been around the QLD drag race scene for years?
Roo
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You are on the money Roo, since 1966. This dragster belonged to John, the car I drive belongs to his brothers Joe & Jim.
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Cheers mate. Cool pic. Very similar to what I'm building.
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Rat, can I ask why you went with a 727 instead of a c4?
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Probably the same reason I'm using an FMX. Its what I've got and it will get me down the strip for now ;D
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Why a 727, simply it came at the right price. It was already beefed up as it came out of a Customline. It was shortened to fit in the dragster and used a push button shifter.
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So, custom bellhousing or an adapter? Also, what heads and cam are you running. Using the Wallace calculator it's showing 275rwhp so 325 or so crank. just wondering what it took.
Thanks for answering ;)
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Goinbroke2, apologies for the slow reply, factory cast iron 351 Windsor heads ported and the engine plate was duel bolt pattern.
Not 100% on the cam, 295 duration I think.
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Old thread,but bored. I was running some of the numbers thru wallace calculator and they are surprising close. Makes me fee better about potential of my combo. 1650 at 950 to 1000 hp(conservative compared to desktop dyno). Numbers ar better than I am hoping for,hey sometimes a surprise can be good,I guess. Now if can get some runs to get to where car(AKA tuner) is doing job right and see how close.