Drag Racing Tech - Ok guru's I cant get into the 10's WTF???

Ok heres the story

@3800lbs in 40* air, DA was in the center of the earth about -1800ft it went 11.02@124 with the converter locking in the back 1/2, 60ft on that pass was 1.53. This was on 325/50 M/T radials.

SOOOOOOOOOO, I take close to 40lbs of weight out of the car(rear bumper support, door bars), put 28x10.5W slicks on the car. Disable the converter lockup in the back 1/2(trans guys says its bad for the input shaft) DA not as good as the previous 11.02 outing, probably+500 or so.
Car runs 11.03@122.8 , 60ft 1.53. Temp was in the mid 50's with higher humidity than the 11.02@124 run.

If anyone knows how to get the DA for Hattiesburg Miss last night at 7:00PM I would appreciate it.

I figured out the Da at the time of the run, was -600ft, the previous runs were at -1850 ft, so technically I guess the car IS quicker, just not on the slip.

Seems like the slicks slowed it down in the back 1/2, like the car was laboring, dropped 450 rpm through the traps with the slicks.

Car "FEELS" like it leaves much harder on the slicks, picks up the tires a foot and a half, ran a best 60 ft of 1.50

It ran a best of 7.01@97.2 in the 1/8

The converter will stall 3000 ish on the foot brake and flash to 4100/4200, the converter is the problem?



The front of my head is FLAT from doing this:bang:


David

Going from the drag radial to the slick will cost you a couple mph on the other end. I would stick with the radial and play with the air pressure and see if you can get a better 60' good luck

try going down a tire size, 325's are huge for a car thats just trying to get in the 10's.

try going down a tire size, 325's are huge for a car thats just trying to get in the 10's.

Well I did that to try and hook it on the street, it will get a 200 shot on it soon, hoping to run in the 9's. Another reason for the 325.

David

What was the zipcode for the racetrack you raced at. There is a website with historical data that you could look it up.

Locking up your converter the first time and not the second probably made a bit of MPH difference. Next time make a pass with it locked to rule out/factor the difference.

Too much tire for your combo, I did that seven years ago when my Formy had a 422ci iron block. I went 11.doh with 26's on a 1.53 and then went to a 28 and went 1.50 and ran 11.doh with less mph.

how much power was your 422 making John? off topic, i know.

472rwhp locked, 4L60E, 4.10's, 3600 raceweight Went like 11.02@122.8 or something on 28's on like a 1.5x 60 ft time. Unlocked it was around 450rwhp I think.

Fastfat needs less tire, or more gear, or more converter and more gear etc... Your rig is so heavy you don't need 28's on motor.

I ran a faster 60' on my M/T 325x50 drag radials than I did on 26x10x15 slicks. you need to try to get you sixty done a little. I see you have a 4k converter what gears do you have?

It has 4.11 gears. The slicks growing I think hurt me.....BUT the slicks are 1/2 the weight of the drag radials.


As you guys can see, I am frustrated with this car. It made 441 RWHP unlocked and 463 locked...I feel like it has the power to run 10.99. I know it is heavy, I was always taught the heavier the car them more tire it needs. Think I should try a regular 28x10 stiff sidewall tire? I have that much tire to try and hook it on the street, which it wont.

It "feels" like it dead hooks, I have not any video of the car. Guys watching the car say it leaves well.

Looks like some Kirkey seats and other lightweight items are in my future. Car makes good power just carrying too much weight to run 10's on motor. 3750 lbs it seems it just too much to overcome with 441 rwhp.



David

At 7pm the weather was:

6:53 PM 53.1 °F / 11.7 °C 37.0 °F / 2.8 °C 55% 30.30 in / 1025.9 hPa 10.0 miles / 16.1 kilometers Calm Calm - N/A Clear

The DA calculates out to -700ish. Pretty damn good air.
http://www.weatherunderground.com/

I wouldn't change the tire, it's not working that bad, 1.5's isn't that great but it isn't horrible, with 122 mph you'll be able to run 10.99 easy, only thing stopping you now is a few 0.0x's in the 60 ft.

I think back when I was running in the 10.90's my 60ft averaged about a 1.45-1.47, so you're not too far off running in the 10's, besides once you spray the car it is going to be a whole new animal, less gear and a bigger tire and lower stall works awesome with nitrous cars, you just have a trade off when you try to get the most from your combo on motor only. I'd tune on the chassis and try to get a little more out of the 60ft and then start spraying the car.

At 7pm the weather was:

6:53 PM 53.1 °F / 11.7 °C 37.0 °F / 2.8 °C 55% 30.30 in / 1025.9 hPa 10.0 miles / 16.1 kilometers Calm Calm - N/A Clear

The DA calculates out to -700ish. Pretty damn good air.
http://www.weatherunderground.com/

Can you look up the DA for Dec 16th 2007 for the same track at 6:30 pm.

When I ran the previous 11.02 the DA was -1800 feet. So the car technically IS quicker. But it frustrates the hell outta me.

I personally think the converter is too tight, but I think it will be good for the spray with some 295/65's on the car and the 4.11 gear.

I have been told on a 150 shot this car could go 9.90's.....YES I could DIG that.

David

Did you ever try to flash the convertor? (Not brake torque it off the line, just come off idle)

I did the math for 12/16 and it looks to be between -1300 and -1600 feet depending on the track altitude and the time of day you raced (I assumed 7pm like above).

So if you ran the same at half the negative air density, be happy. With the same air (all be it rare to find it that good) you would have run tens.

Like the other people have posted, either pull weight, add gear/converter or tinker for that little extra oomph to get you across. Weight would be your biggest and easiest change.

Put some 26's on it, hold the rpm's at about 1800 and flash it off the line.

Or put that pig on a diet. LOL

Heavy cars need alot of gear to help get them movin, the 26's should help you out just enough I would think.

David,

My car makes similar power to your Na and I'm going to be hitting the car with a nice shot but I'm going to try running MT 275/60/15 instead like some of the other people are saying 325's are a lot of tire. Also there are a lot of people going sub 9's on the 275's.

Good luck.

You are at the point where you might need to change something. Maybe loosen up the converter a little, or run less tire. 11.02 @ -1800 DA means that in regular weather you are like an 11.1-11.2 car.

I'd consider loosening up the converter a smidge. Research with your local guys but I've also heard that having the engine a bit leaner will make the converter hit harder, but that's just me quoting something I read.

My car went 10.92 on a 1.48, and that was the best weather I see up here, like maybe 500 DA. You need a 1.4 short time or more power to hit 10's. You could always try to make another 20hp too.

Between the super heavy race weight and the huge drop in RPM from the tires growing, i think you have your culprit for why the car won't go any faster.

If you go with a looser converter it isn't going to run as well when you put the spray to it. Same goes with more gear, it'll prolly run out of breath on the top end if you put enough gear in it N/A.

Ditching weight would probably be your best option.

Don't go to a 26" tire. 28" is just fine, it will help keep you from fighting traction problems on down the road.

I run 325/50's,4.10 gearing/3600 stall. As you can see, in my sig, it's working great on the juice but not so good on motor. Check out my video, first run ever on the juice.

It's not easy to have it both ways, but this guy can run 10.9 and 9.99 but he needs the car to 60 ft better anyway. Think about it. Car needs a 1.4 on motor to hit 10.9 and most likely he will need that extra kick on the bottle too. To go 9.99 on a 150 shot is not easy.

I think you need more converter. You need like 4800-5500 to run stronger on motor, and cut like a 1.45-1.48 short time. You could keep the 28's but you would again need more converter because you are only going to slow down as it gets warmer and hitting that 9.99 will be even hard, you might only go 10.2 on a 150 shot.

It's not easy to have it both ways, but this guy can run 10.9 and 9.99 but he needs the car to 60 ft better anyway. Think about it. Car needs a 1.4 on motor to hit 10.9 and most likely he will need that extra kick on the bottle too. To go 9.99 on a 150 shot is not easy.

I think you need more converter. You need like 4800-5500 to run stronger on motor, and cut like a 1.45-1.48 short time. You could keep the 28's but you would again need more converter because you are only going to slow down as it gets warmer and hitting that 9.99 will be even hard, you might only go 10.2 on a 150 shot.

Yeh, I think it will run a 9.99 with a 150 shot, the converter being too tight will help that. 1 second on a 150 shot should be about right. Gotta remember I have a 7100 rpm limit on LT1 ecm. I think I could loosen the converter and EASILY get into the tens, but I want to spray the car.

Yeh I know I am like everyone else, I want both worlds. But you cant have it.

I will spray it here in a month or so and see how it does.

I am gonna order some Kirkey seats to get another 40 lbs out of the car. Gonna remove the passenger airbag also. ALot of work for 15 lbs...but gotta have it.

And on a lighter note, no pun intended, I am scheduled for a Lapband at the end of this month...so the driver is about to get lighter also.


David

4200 is not enuff converter for 10.9 at your power and raceweight, it's clearly close. I think you should loosen up the converter 400 or so, after you spray it. My guess is you will go 10.2 on the hose. I went 1.48 on motor and 1.38 on the sauce, just missed 9.99 bottle pressure was low. My current converter goes to about 4800 on the brake and I'm going to put in a 5500 converter which will rock on motor but I'll need a 2step for the sauce otherwise it will flash to like 6500.

David, I also think the weight is an issue. Trying to get that much mass moving will really pull the motor down if everything isn't right (ask me how I know). All you need is a little more 60' and you're there.

Keep playing with it, you'll get there.

I don't usually give this out but...

I'm making 626 at the wheels on motor with 3780 lb raceweight going 10.15. This should give you an idea of what you need to get close to the 9's.

Thanks John, what size shot was that on what kit? I got a guy on the hook for a NOS Big Shot plate, adjustable to 300hp. For a damn good price.

Dave, thanks for the insight. I think on the spray I will 60ft better than you. I sixty foot consisitent 1.52/1.53 on the motor, with 470 to the wheels....should at least go mid 1.40's on the spray?? You guys really dont think it will go into the 9's on a 150 shot out of hole running 11.03 now? I was thinking that was a sure thing.....there I go thinkin again LMAO.


I am really not studying not it right now. I am getting squared away for this surgery and will not be able to drive the car for a while.But while I am down it will get spray installed along with a set of Kirkey economy drag seats.

I have beat the CRAP out of the car and it has not missed a beat....and is very consistent....cant bitch much about that....but I sure would like a 10 sec slip on the motor....I could put a 150lb driver in the car vs my 335 lbs and it would go 10's NO PROBLEM. I almost did that Sunday, but somehow I think thats cheating. Along with removing the air filter, exhaust cutout, removing the passenger seat etc. I want it to run a 10.99 JUST like I drive it on the street.

David

I only had a 4,500 stall in mine and I got it down to mid 1.4 60ft.s and ran 10's on the motor at LACR which is higher altitude than a lot of tracks here, at the sea level tracks it would run 1/2 faster. I would have gone faster with a 5,500 stall on the motor. I wanted it to go faster on the spray.

I personally would keep the converter, 4,200 is a great N20 stall, I ran 1.45 or so on motor and 1.30 on the spray.

Here is my point, do you want to go faster on the motor, which will always be slower than on the nitrous, or set it up to run on the nitrous which it will go fastest with?

You can go 10.90 with a N/A set up and 10.2 on the spray or go with a nitrous setup and run 11.0 and 10.0 on the spray.

Besides running 11.00 is great, running 10.00 is better, who cares how you get there as long as you're having fun and not breaking stuff right :)

Oh I thought I'd add some numbers to give example of some of the runs I did on motor and smaller shots.

10.93@121 1.46 60ft TB

10.30 @ 129 1.43 60ft foot brake

10.0@133 1.40 60ft foot brake

9.30@142 1.30 ft60 TB

People told me my car would run faster foot braking and flashing the converter but every time I left on the nitrous off the Trans Brake it always left harder. I had a th400 in mine though.

Well the goal was to run 10.90 on motor, just like it is driven on the street. Full exhaust, air filter in, full interior.

And what ever it ran on the gas SAFELY(175 shot or less) that is just what it ran. But I tried to get a happy medium with the converter.

But remember I have a 7100 rpm limit with the factory ecm.

But now I would like a 9.90 slip on a 150 shot. I think it will do it on a 150 shot with 50 more lbs out of the car(Kirkey seats and passenger airbag out)


David

David my Formy dynoed 472rwhp locked with old 422ci iron block I had in there, and was 3600 raceweight... so similar to yours. I ran a Yank 4500 TP at the time (4L60E) + 4.10's. I kinda went thru this same thinking a number of years ago, I didn't have enough converter.

I went 10.008 with a 150 NX wet shot, went 133.9mph. I think you should loosen up the converter, run some 10.95's, and then when you spray it it should still work decent. Ideally you will go 1.45 NA and 1.35 N20... a 1.4 going 9.9's means you are not getting traction or leaving hard.

Going 11.02 at 3700 raceweight in -1800 DA is great with a 4200 stall, but I think running stronger on motor well help you run 9.9 on a 150 shot. Think about it.

Now my car went 11.3 NA in the middle of the summer with less timing, and 10.11 on the gun. I subsequently went 11.0 a few months later with nothing changed except NA timing, and that was running 50 lbs heavier than the summer.

I'm hoping to run 10.5 NA with a 5500 converter, and to 2step the car and run either a 100 shot or 150 shot and go for 9.5's but we'll see I might have to settle for a 100 shot and 9.8's.

I shift around 6800 for both, and I'm nowhere close to 7100 thru the traps.

Simple solution, take 50 pounds out of the car and you 'll run 10.90's lol.

[QUOTE=
I shift around 6800 for both, and I'm nowhere close to 7100 thru the traps.[/QUOTE]

On spray or motor?


David

I shift at 6800 for both, and on motor I go thru the traps at like 6200.

I would like to put in my two cents....First of all change one thing at a time. You can change 10 things and spend a bunch of cash and run the same times, so change one thing at a time. Secondly, a 10.5w tire is WAY TO BIG, I don't know who told you to run that tire but that is really a lot of tire . Third , I have seen plenty of guys with too much converter, you can even hear the car driving through the converter. I haven't seen anyone ask about anything to do with the motor you are running. What cam are you running? That has a big factor along with weight and gear ratio.....my thoughts would be to put some more gear in the car . With what you have said I would go with a regular 28x10.5 , tire then see what happens. Then go with something like some 4.56's on those tires. I really don't think it needs more converter, there is a point in which you have too much converter. If your powerband is strong from 3500-7200 I don't think you would need a 5500 stall in it, just my two cents....

There is a track in Rising Sun Maryland that is an NHRA track that just so happens to be 13-14 ft DOWNHILL from the starting line to the finnish line.Now without changing a thing,a little road trip might just be what your looking for.My uncle ran there last year and went 2 mph and 2/10ths faster than he has ever gone!!!

I have come to the conclusion the car does not have enough converter. It will BARELY hold still at 3000 rpm on the footbrake, really 2800 is all it will sit still at.

I know it is too much tire on the track, but on the street on a concrete bridge it will tote the front tires!!!

No worries, it went 11.02@123 with the converter unlocked, I KNOW it will run 10.90 with a 180lb driver vs my 340lbs...thats good enough for me, I built an all motor pumpgas 10 second streetcar...THAT was goal.

I just got back from a 30 minute interstate roadtrip(one way) to a car show in Mississippi...streetcars RULE!


Now I will install the gas and see if I can get in the 9's


Thanks guys

David

I would like to put in my two cents....First of all change one thing at a time. You can change 10 things and spend a bunch of cash and run the same times, so change one thing at a time. Secondly, a 10.5w tire is WAY TO BIG, I don't know who told you to run that tire but that is really a lot of tire . Third , I have seen plenty of guys with too much converter, you can even hear the car driving through the converter. I haven't seen anyone ask about anything to do with the motor you are running. What cam are you running? That has a big factor along with weight and gear ratio.....my thoughts would be to put some more gear in the car . With what you have said I would go with a regular 28x10.5 , tire then see what happens. Then go with something like some 4.56's on those tires. I really don't think it needs more converter, there is a point in which you have too much converter. If your powerband is strong from 3500-7200 I don't think you would need a 5500 stall in it, just my two cents....

My thoughts exactly, except for the gears :D

I say leave the converter alone. I made the mistake of loosening mine. 150 shot was retarded and I was tapped at 6500 before the finish in 4th gear. On a 125 shot I'm at 5800 and finish at 6200 in 4th gear with 4:56's and 29 inch tire. Nitrous and blowers like tight converters.

I say leave the converter alone. I made the mistake of loosening mine. 150 shot was retarded and I was tapped at 6500 before the finish in 4th gear. On a 125 shot I'm at 5800 and finish at 6200 in 4th gear with 4:56's and 29 inch tire. Nitrous and blowers like tight converters.

I am gonna leave the car alone, The big tire, tight converter and 4.11 gear are gonna stay like they are. The nitrous install will start this week.

It will like the spray.


David