60' time vs. trap speed?
- Thread starter WFO
- Start date
Trap speed only goes up a little with a 1.6 vs. a 2.3 60 ft (If the same tire is used) because a quicker 60ft usually means the car left with more boost.
If a tire change is required to go from 2.3 to 1.6, then the trap speed may decrease from the additional drag of the tires (going from skinny radials to soft slicks for example).
Take off between 1.5 X to 1.2 X for every second gained in the first 60 ft.
2.3 - 1.6 = .7 seconds
.7 seconds X 1.2 = .84 seconds
.7 seconds X 1.5 = 1.05 seconds
If a car runs 13.2 @ 110 and a 2.3 60 ft, it will run about 12.36 to 12.15 with a 1.60 60ft.
A tire change would likely be required to make such a drastic 60 ft difference, though so MPH would probably drop from the added resistance of a tire that allows 1.60 60 fts on a 12 second car.
1.70 is a much more realistic goal for a car currently turning 2.3 60 fts. This gives a 12.48 to 12.30 ET in a 13.2 second car.
If a tire change is required to go from 2.3 to 1.6, then the trap speed may decrease from the additional drag of the tires (going from skinny radials to soft slicks for example).
Take off between 1.5 X to 1.2 X for every second gained in the first 60 ft.
2.3 - 1.6 = .7 seconds
.7 seconds X 1.2 = .84 seconds
.7 seconds X 1.5 = 1.05 seconds
If a car runs 13.2 @ 110 and a 2.3 60 ft, it will run about 12.36 to 12.15 with a 1.60 60ft.
A tire change would likely be required to make such a drastic 60 ft difference, though so MPH would probably drop from the added resistance of a tire that allows 1.60 60 fts on a 12 second car.
1.70 is a much more realistic goal for a car currently turning 2.3 60 fts. This gives a 12.48 to 12.30 ET in a 13.2 second car.
this is what i was trying to get at
.all else equal,just a better short time the car will usually slow down,correct?it sounds like it's because the 13 sec/2.3 guy had an extra half second+ to get up to speed than the low12/1.6 guy...is that right?
i realize that most of you guys don't screw around with street tires so i appreciate your input
.has anyone actually run their car on street tires then backed it up on slicks?just wondering what the actual difference could be in mph with no other changes...thanx,sean
This makes absolutely no sense at all. My old cavalier would be on the track for a very long time.... wouldn't help the MPH even though it would have about 18 sec....
Anyway, to relate 60 foot time to MPH, you have to transfer the time you saved in the first 60 feet to the end of the quarter mile.
For example, you cut your 60 ft from 2.1 to 1.8 sec. You saved 0.3 sec. If you transfer that 0.3 sec to the end of the quarter mile, and guestimate how much MPH you would gain in 0.3 sec at the END of the quarter mile, you could get an idea of the MPH increase.
Typically, these cars are not accelerating very much at the end of the quarter mile and in 0.3 sec you would not gain much MPH.
Of course, that depends on what turbo you are using and what kind of HP you have. A car with tons of HP who is mainly traction limited in the 1st 60 ft is still accelerating a lot at the end of the quarter mile and will gain a bigger amount of MPH with the extra 0.3 sec. The more amount of HP, the bigger the gain in MPH with lower 60 ft.
Transfering the 0.3 sec to the end of the quarter mile is not exactly right, but is just used as an analogy so everyone gets the idea of how the shorter 60 ft relates to MPH. In fact, the final MPH relates to the 60 ft MPH rather than 60 ft time. I think its its a good assumption that lower 60 fts have higher 60 ft MPH's though....
I've seen it mentioned quite a few times about shorter time to build MPH with quicker 60 ft, and it makes absolutely no sense and is wrong in every possible way.
UNGN makes a good argument for the reasons MPH can drop by adding slicks, etc.
murph
Damn, are you still trying to figure out why my car has a few extra mph on you when I'm running 18 degrees of timing and 13psi vs your race trim. Give it up. For all who wonder, my car is the 2.3 60' car that went 110mph. I doubt I would lose anything. What WFO forgets to point out is the car spun first and all of second gear. When you spin that far down the track it hurts mph too, not just ET.
I've already done research on this and you can't make a sound decision based on the 60'. Yes, you have longer to accerlerate with a bad 60 but with a good 60 you're going faster sooner.
Why don't you go to the lounge next and post a poll of who has gone 110mph with my combo in street trim and prove yourself wrong again.
I've already done research on this and you can't make a sound decision based on the 60'. Yes, you have longer to accerlerate with a bad 60 but with a good 60 you're going faster sooner.
Why don't you go to the lounge next and post a poll of who has gone 110mph with my combo in street trim and prove yourself wrong again.
Wow, I am going to have fun ripping almost everything you said...
Cavaliers have no HP and have no business being used in an analogy here. Horsepower is the single major factor for obtaining a given MPH for a given weight car. And turbo regals have lots of it!
Are you bad at Math or English? In your example, you loose 3-tenths of a second of time to attain your top MPH.
So you are saying what? Less track time = MPH increase?!
Especially if it is 3-tenths less! Once again - MPH comes from HP and you only have so much time to get there...
What extra 3-tenths? It's 3-tenths less. It is dependent on the HP, not the HP and the turbo (the turbo helps you to obtain the HP but is only a piece of the HP puzzle).
The first eleven words is a more correct phrase. The 60' time has nothing to do with the MPH except that it can add to or subtract from, the amount of time you have to achieve your top MPH.
Good assumption!
Uh...forget it. This is getting redundant. I guess AZGN and I are just wanna be's.
You must mean:
Cavaliers have no HP and have no business being used in an analogy here. Horsepower is the single major factor for obtaining a given MPH for a given weight car. And turbo regals have lots of it!
Are you bad at Math or English?
In your example, you loose 3-tenths of a second of time to attain your top MPH.So you are saying what? Less track time = MPH increase?!
Especially if it is 3-tenths less!
Once again - MPH comes from HP and you only have so much time to get there...What extra 3-tenths? It's 3-tenths less. It is dependent on the HP, not the HP and the turbo (the turbo helps you to obtain the HP but is only a piece of the HP puzzle).
The first eleven words is a more correct phrase. The 60' time has nothing to do with the MPH except that it can add to or subtract from, the amount of time you have to achieve your top MPH.
Good assumption!
Uh...forget it. This is getting redundant. I guess AZGN and I are just wanna be's.
You must mean:
But that assumes that the lower 60 foot is a result of a different (presumably stickier) tire. However, traction has many more variables than just tire adhesion. I would bet however, that if the two tires are the same size, there would not be a sizable difference in MPH as a function of tire adhesion. A car that achieves a quicker 60 foot time because of a HP increase will probably also attain a higher MPH...but both the 60 foot time and the elapsed quarter-mile time are functions of the HP increase. A car that achieves a quicker 60 foot time because of a tire change (same size) will probably ahcieve the same MPH as he still only has Xamount of HP to turn the tires for a given amount of time.
don't flatter yourself
i came to this forum to get facts from drag racers with experience .not to hear more of your viper slaying fairy tales.
the other thread got me thinking.i've been told about the correlation between 60' time and trap speed,and assumed it was true.i came here to find out.look at the facts:
me,you,crazygn and turbo6x2 all have similar builds.
you and crazygn went 12.8/9 @110 with 2.1-2.3 60'.
turbo6x2 and i went 12.3/5 @106/7 with 1.6-1.7 60'.
do the math.you "doubt it would lose any".but you don't know.hell,you don't know much of anything.
no need for that,you look stupid enough already.
why don't you ask these guys(mostly real drag racers in this forum)what they think of your "clogged junkyard convertor/untuned/ta-49 13 psi 110mph run" so for now,go outside and play,the grownups are having a conversation.we'll let you know when it's story time.
So you admit you're trying to find excuses why I had more mph with way less boost. Flattering I tell you. And your combo is not similar to mine, obviously. Just look at the mph. Have fun trying to figure it out. Meanwhile I'll drive my 12 second street trim car and you can drive your 13 second slug.
drive?
hey,it's 75 degrees and sunny here in oregon,i'm sure the track's open in bakersfield.
how bout you hop in the ol hotrod and "drive" it down to the track and make some street trim passes?
i'm sure you could find all kinds of vipers and 900cc crotchrockets to outrun on the way there too...
hey,it's 75 degrees and sunny here in oregon,i'm sure the track's open in bakersfield.
how bout you hop in the ol hotrod and "drive" it down to the track and make some street trim passes?
i'm sure you could find all kinds of vipers and 900cc crotchrockets to outrun on the way there too...
LOL. Jealousy isn't good for you. For your sake I will make some street trim passes as soon as the motor is in the car. I have a different, better combo now so I'm sure I'll hear the excuses. I was already 3mph up on your race trim with my street trim with the old parts. Would you like me to lock the wastegate open so we can be competitive? Maybe I could bypass the intercooler....nah, still wouldn't be close. How about 1 degree of timing??
Two completely different cars aren't really "facts" even if their build ups are similar. Car's are different.
The decreased 60ft times and reduced mph of turbo6x2 are likely do to a high stall, non lock up converter.
If you have a car with perfect traction and a 2000 stall converter it will 60ft poorly, but have high trap mph.
Replace it with a 3500 stall converter it will 60ft well but the trap mph will be reduced.
A car with weak valve springs, 26" tires and a loose converter may never get over 106 mph, no matter how quick it's ET.
Actually the converter was a 3200 lock up converter. One we had set up locally. As far as being concerned with other people's times or amount of boost, no not at all. I'm more concerned in trying to find out just how fast I can go with a hot air set up. I just like seeing the hot airs go fast and achieve their goals.
I've never accused you of anything. I'm glad you're going fast with the hotair setup. I really wanted to keep my car bone stock looking at first. What I realized is that when my car appeared bone stock and went mid-low14s no one believed it was stock anyway. My friend went the same route you're going for a long time and he had a fast car with the GN1s and all. He did get pulled by a Viper by about 2 cars and that's when he bought my old intercooler. It was just too tempting to add 5-6mph for $500. WFO seemed to have something against my car. Claiming I lied about my times with 2 members of this board watching at the track and about 30 locals watching the Viper races is ridiculous. Saying I didn't trap 110mph at 13psi untuned with a huge intercooler, turbo, heads, cam, downpipe, headers, ported intake, etc is ridiculous when you guys believe Herb went 110mph at 18 psi with no intercooler, stock cam, smaller turbo, etc. I do believe Herb, it just makes it easier to believe my times. I hope you hit the 11s soon with no intercooler. We need more fast hotair cars. And don't forget, I haven't done the conversion, it's still the basic hotair setup.
Didn't say you did there cool 84 just trying to make my point. I have a goal of trying to get this to go as fast as possible with a hot air. I'm happy with my car and we think we found the top end issue. I will post results once I return to track. The things we found were interesting at best. I am very pleased with my 60 foot and planned on doing upgrades, such as converter and such. Stock appearing really isn't that big a deal on a hot air, most folks don't even know they exist to begin with. I mean even at a turbo buick gathering I had intercooled folks asking why I "relocated" my turbo??? I just want to see how fast I can go and support all hot airs trying to go fast. Peace out..... LOL sorry for some reason just seemed appropriate...
Scott231,
I'm sorry if my explanation of 60ft time vs MPH didn't make sense to you and others. I was just using an analogy of transferring the time saved to the end of the run and didn't mean for anyone to take it literally.
Of course, I am mainly talking about back to back runs on an identical car with no changes except 60 ft time. Assume on one run you left with little or no boost, and the next time you left with more boost (maybe upgraded brake drums, transbrake, etc...).
So lets say in case 1, leaving with no boost, the car is traveling at 20 mph at 60 ft. In case 2, leaving with more boost, the car is traveling at 25 mph at 60 ft. So we have car 1 at 20 mph at 60 ft and car 2 at 25 mph. Both have the same amount of distance left to the end of the quarter mile but car 2 has a 5 mph head start.
Car 2 will have a slightly higher mph at the end of the quarter mile. It will not be a full 5 mph advantage over car 1 because both cars will accelerate alot in the first 1/8th mile but will sort of level out at the end of the quarter mile (weaker top end plus aero drag, etc). It may only translate into 1 mph or so difference.
As probably anyone can agree, if you are going faster at 60 ft, it will take you less time to complete the full quarter mile run. So for my example, not only will you have a slightly higher MPH, you will do it in less time. If a car has an even shorter 60 ft time and is going a lot faster at 60 ft, it will have an even higher final MPH, and take even less time to comple the quarter mile.
That, Scott231, is why I said it makes no sense when you said that the shorter amount of time you are on the track, the less time you have to gain MPH. Typically, its just the opposite. The quicker you can complete a given distance, the faster you are going.
Sorry if I'm being a pain or anything, I just wanted to make sure people understand exactly what is going on and try to prevent people from making bad statements. While generally it is true if you have more time you can increase your MPH while driving around. But at the track we are talking about a fixed distances. The more time you take getting up to a certain speed, the less distance you have left to increase your MPH.
murph
I'm sorry if my explanation of 60ft time vs MPH didn't make sense to you and others. I was just using an analogy of transferring the time saved to the end of the run and didn't mean for anyone to take it literally.
Of course, I am mainly talking about back to back runs on an identical car with no changes except 60 ft time. Assume on one run you left with little or no boost, and the next time you left with more boost (maybe upgraded brake drums, transbrake, etc...).
So lets say in case 1, leaving with no boost, the car is traveling at 20 mph at 60 ft. In case 2, leaving with more boost, the car is traveling at 25 mph at 60 ft. So we have car 1 at 20 mph at 60 ft and car 2 at 25 mph. Both have the same amount of distance left to the end of the quarter mile but car 2 has a 5 mph head start.
Car 2 will have a slightly higher mph at the end of the quarter mile. It will not be a full 5 mph advantage over car 1 because both cars will accelerate alot in the first 1/8th mile but will sort of level out at the end of the quarter mile (weaker top end plus aero drag, etc). It may only translate into 1 mph or so difference.
As probably anyone can agree, if you are going faster at 60 ft, it will take you less time to complete the full quarter mile run. So for my example, not only will you have a slightly higher MPH, you will do it in less time. If a car has an even shorter 60 ft time and is going a lot faster at 60 ft, it will have an even higher final MPH, and take even less time to comple the quarter mile.
That, Scott231, is why I said it makes no sense when you said that the shorter amount of time you are on the track, the less time you have to gain MPH. Typically, its just the opposite. The quicker you can complete a given distance, the faster you are going.
Sorry if I'm being a pain or anything, I just wanted to make sure people understand exactly what is going on and try to prevent people from making bad statements. While generally it is true if you have more time you can increase your MPH while driving around. But at the track we are talking about a fixed distances. The more time you take getting up to a certain speed, the less distance you have left to increase your MPH.
murph
The physics is with murph on this one.
The only way a "spinning tire Run (slow 60ft)" could equate to higher mph is if the spinning tires act as a slipping clutch, allowing the absolute maximum HP the track can take (vs. a non spinning tire run where less than the max HP is utilized).
The concept that it's faster because it has more time to accelerate is silly. Time is funtion of acceleration, (the faster it accelerates the less time it spends on the track) and not the other way round.
The only way a "spinning tire Run (slow 60ft)" could equate to higher mph is if the spinning tires act as a slipping clutch, allowing the absolute maximum HP the track can take (vs. a non spinning tire run where less than the max HP is utilized).
The concept that it's faster because it has more time to accelerate is silly. Time is funtion of acceleration, (the faster it accelerates the less time it spends on the track) and not the other way round.
Similar threads
