SeanDezart
Well-Known Forum User
And if Steve loses - what is the forfeit ,
And are you two gonna do a stage-act if I win ;-) ?
And are you two gonna do a stage-act if I win ;-) ?
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drag challenge
- Thread starter ben240z
- Start date
SeanDezart
Well-Known Forum User
Only his most handsome face ! Oooh, those chubby cheeks !
No way, sorry no forfeit from me I am afraid -- mainly because
1. I'm not that daft
2. Nothing in life is certain
3. I dont have anything to prove (I have already proved my point and acheived the time)
4. It may be ok for Mancunians to show their butts in public, (it is probably part of some mating ritual anyway) -- however, down here, it gets you a good kicking
besides I have already said that when the time gets beaten £25 goes to the club funds. That £25 will be index linked of course
Oh can I just clarify Dave ,that its the most recent time (what ever that is) that you have to beat, not just the 13.72 as I am planning to go a little quicker this year
. And would hate to deprive the shoppers just on a technicality
SeanDezart
Well-Known Forum User
Not sure if this is answerable :
how much bhp does it take to send 100 kgs up the strip over a 1/4 mile in 14 seconds ?
Is there an equation to calcualte how much power to do the same when one increases or decreases that weight ?
Told you I was sh**e at maths !
how much bhp does it take to send 100 kgs up the strip over a 1/4 mile in 14 seconds ?
Is there an equation to calcualte how much power to do the same when one increases or decreases that weight ?
Told you I was sh**e at maths !
SeanDezart
Well-Known Forum User
Where ET is estimated time ?
So ?hp = 2756 (1250kgs) divided by ((13.5 divided by 5.825)x3)
396 hp ?
So ?hp = 2756 (1250kgs) divided by ((13.5 divided by 5.825)x3)
396 hp ?
SeanDezart
Well-Known Forum User
Oops !
So ?hp = 2756 lbs (1250kgs) divided by ((13.5 divided by 5.825) to the power of 3)
221 hp ?
And 248 bhp needed for 13 seconds !
So, I might hope for somewhere between 13.2 and 13.5 seconds ?
So ?hp = 2756 lbs (1250kgs) divided by ((13.5 divided by 5.825) to the power of 3)
221 hp ?
And 248 bhp needed for 13 seconds !
So, I might hope for somewhere between 13.2 and 13.5 seconds
?221 is correct for a 13.5 second run
Dont forget that is rear wheel HP
Generally a 240 has about 18% drive chain loss from engine to tyres so to work backwards to get flywheel HP -- add 22%
221 + 22% = 269.6 flywheel HP --- possible with a stroker but unlikey on a 2.8 unless serious head and cam mods (kidney shaped chambers, BIG lift cam) Oh and throttle bodies and engine management
Plus dont forget these are hypothetical values and only apply in an ideal world
The real world will be slightly worse.
Take the weight down to say 2590lbs which is the weight of my car+me+fuel on a public weigh bridge and your rear wheel power required for a 13.5 comes to about 208 HP (254 flywheel).
Back work my 13.72 seconds with 2590 lbs and a terminal of 99.97 and you get values between 198.5 and 202 HP RWHP (rear wheel Horse power) which is exactly what we measured on the rolling road (Dave Walkers) last time ----- (see how everything ties up).
A stripped out 240Z (Early shell ,race, single seat no trim etc) weighs in at about 2300 lbs, average Joe bloggs weighs say 170 lbs, half tank fuel about 40lbs
total = 2510 --- HP required to do a 13.5 is 201-204 hp and a terminal of about 101 mph
So I know that unless I make some modification to power/ weight I will not get much lower than 13.72 --- good job I have made them ehh
None of this mathematical modelling takes into consideration launch style, traction, gear change all of these will add a few 1/10ths to the time --but a least you know the quickest achievable under ideal conditions
Dont forget that is rear wheel HP
Generally a 240 has about 18% drive chain loss from engine to tyres so to work backwards to get flywheel HP -- add 22%
221 + 22% = 269.6 flywheel HP --- possible with a stroker but unlikey on a 2.8 unless serious head and cam mods (kidney shaped chambers, BIG
lift cam) Oh and throttle bodies and engine management Plus dont forget these are hypothetical values and only apply in an ideal world
The real world will be slightly worse.
Take the weight down to say 2590lbs which is the weight of my car+me+fuel on a public weigh bridge and your rear wheel power required for a 13.5 comes to about 208 HP (254 flywheel).
Back work my 13.72 seconds with 2590 lbs and a terminal of 99.97 and you get values between 198.5 and 202 HP RWHP (rear wheel Horse power) which is exactly what we measured on the rolling road (Dave Walkers) last time ----- (see how everything ties up).
A stripped out 240Z (Early shell
,race, single seat no trim etc) weighs in at about 2300 lbs, average Joe bloggs weighs say 170 lbs, half tank fuel about 40lbstotal = 2510 --- HP required to do a 13.5 is 201-204 hp and a terminal of about 101 mph
So I know that unless I make some modification to power/ weight I will not get much lower than 13.72 --- good job I have made them ehh
None of this mathematical modelling takes into consideration launch style, traction, gear change all of these will add a few 1/10ths to the time --but a least you know the quickest achievable under ideal conditions
SeanDezart
Well-Known Forum User
Last 3.0 ltr stroker from you know who gave 238 at the rear wheels which when using your calculation of 22ù equates to 305 at the flywheel ! Yeah - right !
My 3.1 I expect to have 270 at the flywheel - 210 then at the rear wheels ! So, I won't be troubling you and D.Dave unless my car is lighter than 2756 lbs ;-) I've lost 11 lbs since Christmas too - it all helps !
Of course, I might hope for more power too so we'll see - I have to be at a drag run first - right ?
""None of this mathematical modelling takes into consideration launch style, traction, gear change all of these will add a few 1/10ths to the time"" This is what I've said all along Steve and isn't 'launch style (or in your case - control) a factor in reaction time ?
My 3.1 I expect to have 270 at the flywheel - 210 then at the rear wheels ! So, I won't be troubling you
and D.Dave unless my car is lighter than 2756 lbs ;-) I've lost 11 lbs since Christmas too - it all helps !Of course, I might hope for more power too so we'll see - I have to be at a drag run first - right ?
""None of this mathematical modelling takes into consideration launch style, traction, gear change all of these will add a few 1/10ths to the time"" This is what I've said all along Steve and isn't 'launch style (or in your case - control) a factor in reaction time
?Ehh!
238 + 22% = 290 ---- muppet
And as I have said all along, the maths will give you a maximum or best possible figure -- its up to you to achieve it --- maths cant cater for "stupid drivers" Duh!!!!!""None of this mathematical modelling takes into consideration launch style, traction, gear change all of these will add a few 1/10ths to the time"" This is what I've said all along Steve and isn't 'launch style (or in your case - control) a factor in reaction time
SeanDezart
Well-Known Forum User
I figured 238 = 78% and therefore one should divide 238 by 78 then multiply by 100 (to get the original 100% before drive-train loss) !
And then I read that you were quoting 18% drive train loss - me muppet but I thought that 22% was closer to what I've heard, 18% is a very well set up car - no ?
And then I read that you were quoting 18% drive train loss - me muppet
but I thought that 22% was closer to what I've heard, 18% is a very well set up car - no ?
SeanDezart
Well-Known Forum User
But then again, at 'only' 18% loss and 'only' 270 bhp, with a weight of 2756 lbs and a perfect launch and gearchanges, I could beat you !!!!!!!!!
SeanDezart
Well-Known Forum User
Now, how to lose more weight.......?
Yes you could, but dont forget the "driver" element
It took me months to get my launch "right"
(I have 40 tickets to prove it) and even now I feel that there are many areas of improvementregarding 18%
Dont forget that the early Z drive chain is very simple and most of that 18% is tyre losses
SeanDezart
Well-Known Forum User
There you are you see - the moment I get all het up and excited you dampen it down and say 'arrh, yes but then there's the driver element" ! Now, if a driver isn't the most variable factor in the whole set-up.....
Not only do we need an identical car and engine but the same driver to test carbs and TBs ;-)...and it needs to be someone very objective to avoid ANY 'mis-management' !
I feel confident (with a few pointers from experienced people) that my launch style and reaction time will impress. After that is the ability of the car to deliver but my gearchanges won't be at 7500 like yours !
Not only do we need an identical car and engine but the same driver to test carbs and TBs ;-)...and it needs to be someone very objective to avoid ANY 'mis-management' !
I feel confident (with a few pointers from experienced people) that my launch style and reaction time will impress. After that is the ability of the car to deliver but my gearchanges won't be at 7500 like yours !
Sean, everyone who has never raced says that.
The reality IS different.
Trust me. 40 launches is a minimum figure to start feeling "reasonably competent".
Just remember the phrase with the flag and the waste material from male bovines rear ends in it.
All this theotetical talk and formulas is just talk. (albeit mildly entertaining)
The only thing that has any shred of credability in it is "the pink slip."
And as far as racing in the 21st century goes Skiddell is the only one with a ticket.
I dont mean to detract from Steve adams and Daves times, but they are now history AFAIC.
SeanDezart
Well-Known Forum User
TheMinel said:
Pete,
Anything is possible, maybe that extra touch of youth I'm still clinging to will be, for once, positive !
The first time I was at Santa Pod, my reaction time was, quote 'couldn't be more perfect for a human being' un-quote ! I honestly can't remember what it said on my slip but it impressed the person handing it out !
I could, after 40 runs, completely fluff one - can work the other way too !
Either way, it does make me keen to have a go which is what counts - right ?
Sorry I'll be leaving you back in the 14s though Pete
No Sean, thats just a rhetorical phrase with no element of truth in it.
Again No. People with that amount of practice dont"completely fluff" starts.
The more you do the more consistent you become.
Only rank novices "completely fluff" starts.
Wrong again. Sorry. Having a go is worthy of encouragement.
But as previously stated only pink slips count.
No wrong again on two counts this time. Firstly you have no times at all for your car let alone a sub 14sec run. So until you do your are in the land of "wishful thinking"
Secondly there are posted sub 14s times for NA Z32s(without nos). Since I am already the fastest Z32 NA driver/car combo here in the UK at the moment I am well capable of following our American friends into the 13sec bracket. Especially If I use one of the concrete launch pad tracks to run on.
And finally what is the reason for "The Minel" quote in your reply??? Its not even from this thread is it????