How To Choose A Modification

tripleblack · 08-25-2005, 08:57 AM

How to Choose A Modification

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I've noticed how often newbies (and not so newbies confused by the multi-voiced claims of the marketplace) seek help in determining which mod to start with, add on, or benefit from. Trying to find a logical method of quantifying in some way all these diverse mods is difficult, but I think I've come up with a method that will often work.

The Augus issue of MMFF features an column by Richard Holdener that contains some simple math one can use to compute the effect of a given modification on a given car. The logic goes:

1. Compute the number of g's (gravities) you car produced in current form. The example he used was a 5 speed car with 400 lb feet of torque, a 3.27:1 final drive and a 2.95:1 first gear ratio. Drivetrain efficiency was set at 87% (average for a 5 speed - automatics would be lower) to compensate for lossed in the clutch, transmission and rear, and the tires had a rolling radius of 1.1 foot (racing slick, but close to that of many 315 drag radials as well). The car in the example weighed 3000 pounds. Here is the formula:

2.95 x 3.27 x 0.87 x 400 / (divided by) 1.1 = 3,356.98/1.1 = 3051.80 pounds of thrust. Next divide the thrust by the weight of the car:
3051.80 / 3000 = 1.017 g's of acceleration.

Changes to any of the variables will rais or lower the acceleration number, ie, add 100 lb/ft of torque with a nitrous kit, and you get 1.27 g's.

Change to 4.10 gears, and you get 1.278 g's.

Reduce the weight of the car by 600 lbs, and you get 1.271 g's.

Obviously you can also dollarize the equation, assigning the cost of the modification to the g's, ie:

Nitrous kit costs $1200, you gain .25 g's, the cost is $480 per .1 g gained.

Gears cost $600, you gain .25 g's, the cost is $240 per .1 g gained.

As you can see, the better investment purely from this standpoint are the Gears - more "bang for the buck".

The article contains many caveats regarding things like aerodynamic drag not being factored into the equation - and this is true. But this forumula is at least invaluable in prioritizing the various modifications in at east a quasi-scientific manner. Just plug in your particular variables, and you have a number that means something.

If you can find it, seek out the article and read it (he has a similar write-up in the July issue regarding lateral acceleration, ie, handling and braking, that has similar potential in determining which handling modifications to do first.

I think aerodynamic loads get discussed next month. I for one am all ears.

tripleblack
__________________
tripleblack
2002 GT Convertible - Cervini ram air & bumper - Accufab 75mm - C&L plenum - MAC CAI - Bassani X pipe - Comp Cams - Diablo Predator tune - Steeda G-Trac Stage 1 - PIAA driving lights - Steeda Tri-Ax - Steeda strut tower brace - Steeda C/C plates - Steeda Sport Springs - Optima Red Top battery - Assorted billet and bling (just a little) and custom paint - 18x9 & 18x10 polished bullits - Coming soon to this stang...
Kenne Bell 1.7 sc kit

*Lances03SVT* · 08-25-2005, 01:51 PM

Very nice.

Lightning247 · 08-25-2005, 02:24 PM

Nice. In conclusion...

DON'T FEAR THE GEAR!

Philip K.

*madmatt* · 08-25-2005, 03:33 PM

Nice article. I like it.

tripleblack · 08-25-2005, 07:10 PM

Sorry 'bout the typos. Should have proofed it.

Also, hope everyone noticed that weight has a slot in the equation. A modification that increases power AND weight at the same time has a multiplier effect, ie, an aluminum drive shaft might increase power to the rear wheels and shave weight at the same time. Modifications like aluminum heads (I know, only for older cars, but still, the idea is that this formula works for all cars) would be a double hit, too.

Just a reminder - if you use the formula to analyze a future mod, check to see if the mod will save (or add) weight. In fact, I noticed in his nitrous example that he didn't add the 20 pounds or so that the system would weigh.

tripleblack

ModMotorRacer · 08-25-2005, 10:31 PM

Underneath all that technical crap is the same adage that has been around for years.....power vs weight...plain and simple. Its being over examined. Perfect example is an O/R X pipe compared to a stock H. 99% of your gain is because you just dropped 30lbs, not because you picked up 10rwhp. Or adversely those C&L freakin caveman club inlet tubes....those things weigh a ton compared to the stock plastic units..so any actual hp gains you get from them is instantly negated because of the extra weight. Its not rocket science, just common sense. Keep these 3 figures in mind when buying parts.
10rwhp= .10(one tenth of one second at the track)
10lbs sprung weight=.010(one hundredth of one second at the track)
10lbs unsprung weight= .10
These are not end all be all numbers but they are pretty damn close.

Adam

tripleblack · 08-26-2005, 07:35 AM

Common misconception. If you drop 30#, your gain (using the example above) would be:

3051.8 / 2970 = 1.03 g

Whereas the 10hp gain would be:

3128 / 3000 = 1.04 g (slightly more advantage from 10 hp vs 30# wt. reduction)

Since you get both with the hypothetical change, the numbers would be:

3128.1 / 2970 = 1.05 g

Given a choice between shaving 30# or adding 10 hp, add the 10 hp. You're better off, particularly since more hp will help to overcome the increased aero load generated by more acceleration, etc.

As for the C&L intakes, they are definitely heavy suckers. Based on shipping weights, they look to weigh 9 pounds more than the plastic oe. C&L claims they add 7hp to an 02-03 GT.

Using our example mule, the numbers would be:

3128.1 / 3000 = 1.04 before the C&L

3181.5 / 3009 = 1.06 after the C&L - a clear but not earthshaking gain.

for the 7hp gain from the C&L to be negated to parity, it would have to weigh about 50 pounds more than the oe plastic intake.

However, if the question is whether the 7hp gain (and 9 # weight disadvantage) is worth the $100 it would cost - probably not a good modification for most people. Cost to benefit ratio is rather low. Just good common sense.

tripleblack

Quote:

Originally Posted by ModMotorRacer

Underneath all that technical crap is the same adage that has been around for years.....power vs weight...plain and simple. Its being over examined. Perfect example is an O/R X pipe compared to a stock H. 99% of your gain is because you just dropped 30lbs, not because you picked up 10rwhp. Or adversely those C&L freakin caveman club inlet tubes....those things weigh a ton compared to the stock plastic units..so any actual hp gains you get from them is instantly negated because of the extra weight. Its not rocket science, just common sense. Keep these 3 figures in mind when buying parts.
10rwhp= .10(one tenth of one second at the track)
10lbs sprung weight=.010(one hundredth of one second at the track)
10lbs unsprung weight= .10
These are not end all be all numbers but they are pretty damn close.

Adam

Shambles · 08-26-2005, 08:31 AM

Stchuckzored

stangb16a · 11-11-2005, 12:39 PM

i would think measuring performance with a first gear acceleration number would not be that beneficial. there is a lot of thrust in first gear, but when your in third you really start to notice that all that hp isnt doing anything in a heavier car. i'd rather stick to power to wieght ratio numbers. less math too. but that is just my opinion.

ModMotorRacer · 12-14-2005, 09:32 AM

Quote:

Originally Posted by tripleblack

Common misconception. If you drop 30#, your gain (using the example above) would be:

3051.8 / 2970 = 1.03 g

Whereas the 10hp gain would be:

3128 / 3000 = 1.04 g (slightly more advantage from 10 hp vs 30# wt. reduction)

Since you get both with the hypothetical change, the numbers would be:

3128.1 / 2970 = 1.05 g

Given a choice between shaving 30# or adding 10 hp, add the 10 hp. You're better off, particularly since more hp will help to overcome the increased aero load generated by more acceleration, etc.

As for the C&L intakes, they are definitely heavy suckers. Based on shipping weights, they look to weigh 9 pounds more than the plastic oe. C&L claims they add 7hp to an 02-03 GT.

Using our example mule, the numbers would be:

3128.1 / 3000 = 1.04 before the C&L

3181.5 / 3009 = 1.06 after the C&L - a clear but not earthshaking gain.

for the 7hp gain from the C&L to be negated to parity, it would have to weigh about 50 pounds more than the oe plastic intake.

However, if the question is whether the 7hp gain (and 9 # weight disadvantage) is worth the $100 it would cost - probably not a good modification for most people. Cost to benefit ratio is rather low. Just good common sense.

tripleblack

Sorry but I don't have the education that you do, but I do have the real world experience from actual testing. None of those numbers are always true. Like I said, overanalyzing is confusing to many. I know what works and what doesn't, and decreasing your weight will benefit your ET's much more than an increase in power. Both are ideal. The "aero" affects you speak of are not going to make or break anyone at the 12-13sec levels of racing. Not to mention, the lighter weight/rotating assembly will be much easier on parts. Thats learned, and not from a book.

More power with more weight breaks parts....period.

Adam

tripleblack · 12-15-2005, 08:11 AM

The whole idea of the post was not to argue any particular method of going faster is "superior", just that when choosing between alternatives (usually in a dollar-driven, cost-is-an-object real world) it helps to have a logical process to help you vs just anecdotal evidence.

The example you sited was a very good one - and one that many folks will be choosing between right about now.

As for "overanalyzing", the math is 8th grade level at most. Its simple to use, and takes little time.

As for decreasing your weight benefiting your ets much more than an increase in power, without quantifying either side of the equation, this is impossible to prove. By this philosophy a gain of 150hp would be less advantageous than a loss of 3 pounds in weight.

Experience is supremely important. But there is a place for science as well.

As for education, I just test well .

tripleblack

Quote:

Originally Posted by ModMotorRacer

Sorry but I don't have the education that you do, but I do have the real world experience from actual testing. None of those numbers are always true. Like I said, overanalyzing is confusing to many. I know what works and what doesn't, and decreasing your weight will benefit your ET's much more than an increase in power. Both are ideal. The "aero" affects you speak of are not going to make or break anyone at the 12-13sec levels of racing. Not to mention, the lighter weight/rotating assembly will be much easier on parts. Thats learned, and not from a book.

More power with more weight breaks parts....period.

Adam

ModMotorRacer · 12-15-2005, 11:08 AM

All I can tell you is that I am a bracket racer, so small increases in power and small increases/decreases in weight sometimes make a huge difference and sometimes don't. There are so many other factors that your "8th grade" math isn't taking into consideration. I think that its great that you have formulas worked out, but unfortunately there is much more to it than that. I don't use hp numbers to calculate anything which is the biggest mistake you can make. Especially manufacturer provided numbers. Weather, track conditions, track temp, wind, etc etc etc, are the only real numbers that matter. You don't race a computer or a calculater.

12-15-2005, 11:39 AM

So when lookin at the G's, Does that mean that 4:10's have the same performance gain as nitrous?
Can anyone confirm this by when that have felt when upgrading one or the other?

tripleblack · 12-15-2005, 02:52 PM

It would be fun to bench race alternatives in a race-oriented thread - its just that the idea here was simply to lay out an alternative method of prioritizing modification decisions. The fact that it doesn't help a racer (who if he's half serious is far beyond deciding between spending his allowance on either a CAI or a set of gears) is not surprising. Good luck to you in your efforts - I hope next year is your greatest ever.

tripleblack

Quote:

Originally Posted by ModMotorRacer

All I can tell you is that I am a bracket racer, so small increases in power and small increases/decreases in weight sometimes make a huge difference and sometimes don't. There are so many other factors that your "8th grade" math isn't taking into consideration. I think that its great that you have formulas worked out, but unfortunately there is much more to it than that. I don't use hp numbers to calculate anything which is the biggest mistake you can make. Especially manufacturer provided numbers. Weather, track conditions, track temp, wind, etc etc etc, are the only real numbers that matter. You don't race a computer or a calculater.

tripleblack · 12-15-2005, 03:15 PM

In the example, the results were about the same for the gears/nitrous equation, although including the 20# weight of the nitrous rig would tip the scales ever so slightly in favor of the gears... All dependent on the real world power gained, of course. Nitrous results are influenced by nozzle size, fuel pressure/delivery and lots of good tuning to extract the power. A 50 shot would not equal gears, whereas a 125 shot might be a shade more for your money. Gears are pretty simple, so the equation is pretty stable when looking at them, including seeing what happens when you plug in 2nd gear, 3rd, etc., depending on which is more important to your application. A better overall average could be achieved by running the comparison in all the gears you cover in a typical quarter mile run, if that is the place you plan to orient your car towards... Add them together and weight them as you like, depending on the amount of time you spend in each gear. This is also a way to evaluate strategy - what acceleration would I gain by spending more time in a given gear, etc?

Of course, as has been pointed out, hp that doesn't reach the ground (traction limit) doesn't do you any good. If you raise your power levels beyond your car's ability to use the power, without increasing your chances of hooking up, you are entering the realm of "dyno racing", which like the older "bench racing", can be fun, but proves little.

Also, gears are always "on", and never suffer from an empty bottle.

tripleblack

Quote:

Originally Posted by slappy

So when lookin at the G's, Does that mean that 4:10's have the same performance gain as nitrous?
Can anyone confirm this by when that have felt when upgrading one or the other?

ModMotorRacer · 12-15-2005, 04:22 PM

Quote:

Originally Posted by tripleblack

It would be fun to bench race alternatives in a race-oriented thread - its just that the idea here was simply to lay out an alternative method of prioritizing modification decisions. The fact that it doesn't help a racer (who if he's half serious is far beyond deciding between spending his allowance on either a CAI or a set of gears) is not surprising. Good luck to you in your efforts - I hope next year is your greatest ever.

tripleblack

Thank you and I am sure it will be better than last year. I wish that your formulas were all it took to be competitive, it would be easy to win.

Yes, they could be helpful to a performance oriented guy though.

tripleblack · 12-16-2005, 05:37 AM

Just noticed this post. The first gear numbers are a variable - the formula works for 2nd, 3rd, 6th... use any gear ratios you like, it still computes.

The whole idea of including gearing as a variable in the formula allows you to examine the effect of changes other than weight and horsepower. Without this, how to judge the potential effect of taller gears or swapping to a 6 speed or aod?

Weight/horsepower is an important ratio, as is weight/torque. Being able to compare a series of gear changes that don't alter either weight or torque but DO alter acceleration, et, etc is also good to know.

tripleblack

Quote:

Originally Posted by stangb16a

i would think measuring performance with a first gear acceleration number would not be that beneficial. there is a lot of thrust in first gear, but when your in third you really start to notice that all that hp isnt doing anything in a heavier car. i'd rather stick to power to wieght ratio numbers. less math too. but that is just my opinion.

ModMotorRacer · 12-16-2005, 02:10 PM

Altering gearing does affect weight though, and reciprocating weight too. A numerically higher gear has a thicker ring gear and a thicker pinion gear so it weighs more, and is more of a drag on the drivetrain even though it produces a higher torque multipication. Same with adding a 6 speed tranny , you have all the gearsets for the one more gear making it heavier. Like a C4 compared to a 4R70W, the C4 weighs less but is it really an advantage if I have a custom gearset (steep) 1-3 and a highway OD gear in the 4R70W even if the tranny weighs more? Like i said, its hard to just throw a blanket over everything and call it covered.

Adam

tripleblack · 12-16-2005, 02:44 PM

Absolutely. Some pretty fun fireworks occur when you have a set of gears lightened, too. Its almost scarey the amount of noise and sparks generated in the process. Once one gets serious about a build, weighing various decisions (and parts) becomes an integral element in the plan. Trimming unneeded components from rear differentials and lightening gear sets can subtract considerable weight. Lightweight brake gear and wheels are good places to shave weight, as are losing luxury items like heavy speakers and stereos, etc, etc. The comparison(s) should include the various weights, and any other variables you can predict.

I know I'm overly meticulous about such things as the weights of the various components in a build-up (I keep an old set of scales in my garage - no kidding), but I also know that not every modification will be a success. Adding a little power and a lot of weight is a good way to lose ground. As I mentioned in the original analysis of nitrous vs gears, both changes also should reflect changes in weight. The full nitrous bottle, hoses, solenoids, switches, etc. is not weightless, nor are the higher gears usually the same weight as the oe items (lightening gears is a specialized machining job best left to experts - gears are damn tough, and easily destroyed in the hands of an amateur machinist - there's a good road-racing write-up re. this in a mmff mag from about a year ago).

If anyone wants to compare something and are having trouble with the math, post as much info as you have about the items you're trying to compare and I'll see what I can do with the math side (and I bet Adam can tell you whether or not it will work at all in the real world). The more data you can supply, the better (weight of components, gear ratios, anticipated hp and torque change, etc.). If you're just "estimating" something, thats ok, just keep in mind that the wilder the estimate, the more useless the outcome is likely to be.

tripleblack

Quote:

Originally Posted by ModMotorRacer

Altering gearing does affect weight though, and reciprocating weight too. A numerically higher gear has a thicker ring gear and a thicker pinion gear so it weighs more, and is more of a drag on the drivetrain even though it produces a higher torque multipication. Same with adding a 6 speed tranny , you have all the gearsets for the one more gear making it heavier. Like a C4 compared to a 4R70W, the C4 weighs less but is it really an advantage if I have a custom gearset (steep) 1-3 and a highway OD gear in the 4R70W even if the tranny weighs more? Like i said, its hard to just throw a blanket over everything and call it covered.

Adam

ModMotorRacer · 12-17-2005, 08:00 PM

"If you're just "estimating" something, thats ok, just keep in mind that the wilder the estimate, the more useless the outcome is likely to be."

AMEN TO THAT

GT_Johnny · 07-27-2006, 10:30 AM

Man. Things sure have changed. Back in my day you just took out what you could to lose weight, increased Cubes where possible, got as much fuel in as you could and tried to make it breathe easy. Now a guy darn near needs to know calculus to figure out what to do. Any advice for a mathmatically challenged guy that just wants his car to accelerate quicker? I have too many cars to just dump thousands into the 'stang but I would like to make some minor changes here and there. I have replaced the stock mufflers with Flowmastahs and dropped in a K&N Filter. What would you guys reccomend next? Underdrive pullies? A Power Tuner? Thanks for the input and the forums.

08-25-2005, 08:57 AM	#1 (permalink)
tripleblack Senior Member Join Date: May 2005 Posts: 337	How To Choose A Modification How to Choose A Modification -------------------------------------------------------------------------------- I've noticed how often newbies (and not so newbies confused by the multi-voiced claims of the marketplace) seek help in determining which mod to start with, add on, or benefit from. Trying to find a logical method of quantifying in some way all these diverse mods is difficult, but I think I've come up with a method that will often work. The Augus issue of MMFF features an column by Richard Holdener that contains some simple math one can use to compute the effect of a given modification on a given car. The logic goes: 1. Compute the number of g's (gravities) you car produced in current form. The example he used was a 5 speed car with 400 lb feet of torque, a 3.27:1 final drive and a 2.95:1 first gear ratio. Drivetrain efficiency was set at 87% (average for a 5 speed - automatics would be lower) to compensate for lossed in the clutch, transmission and rear, and the tires had a rolling radius of 1.1 foot (racing slick, but close to that of many 315 drag radials as well). The car in the example weighed 3000 pounds. Here is the formula: 2.95 x 3.27 x 0.87 x 400 / (divided by) 1.1 = 3,356.98/1.1 = 3051.80 pounds of thrust. Next divide the thrust by the weight of the car: 3051.80 / 3000 = 1.017 g's of acceleration. Changes to any of the variables will rais or lower the acceleration number, ie, add 100 lb/ft of torque with a nitrous kit, and you get 1.27 g's. Change to 4.10 gears, and you get 1.278 g's. Reduce the weight of the car by 600 lbs, and you get 1.271 g's. Obviously you can also dollarize the equation, assigning the cost of the modification to the g's, ie: Nitrous kit costs $1200, you gain .25 g's, the cost is $480 per .1 g gained. Gears cost $600, you gain .25 g's, the cost is $240 per .1 g gained. As you can see, the better investment purely from this standpoint are the Gears - more "bang for the buck". The article contains many caveats regarding things like aerodynamic drag not being factored into the equation - and this is true. But this forumula is at least invaluable in prioritizing the various modifications in at east a quasi-scientific manner. Just plug in your particular variables, and you have a number that means something. If you can find it, seek out the article and read it (he has a similar write-up in the July issue regarding lateral acceleration, ie, handling and braking, that has similar potential in determining which handling modifications to do first. I think aerodynamic loads get discussed next month. I for one am all ears. tripleblack __________________ tripleblack 2002 GT Convertible - Cervini ram air & bumper - Accufab 75mm - C&L plenum - MAC CAI - Bassani X pipe - Comp Cams - Diablo Predator tune - Steeda G-Trac Stage 1 - PIAA driving lights - Steeda Tri-Ax - Steeda strut tower brace - Steeda C/C plates - Steeda Sport Springs - Optima Red Top battery - Assorted billet and bling (just a little) and custom paint - 18x9 & 18x10 polished bullits - Coming soon to this stang... Kenne Bell 1.7 sc kit

08-25-2005, 01:51 PM	#2 (permalink)
Lances03SVT Super Moderator Join Date: May 2005 Location: Carthage, Missouri Posts: 9,177	Very nice. __________________ _______________________ 2003 Cobra SOLD

08-25-2005, 02:24 PM	#3 (permalink)
Lightning247 Huge Member Join Date: Jan 2005 Location: Charlotte/ Winston Salem, NC Posts: 233	Nice. In conclusion... DON'T FEAR THE GEAR! Philip K. __________________ 1997 Rio Red Cobra: 2700 of 6961 Tri-Ax \| BBK O/R H-Pipe \| Dynomax Race Bullets \| WMS High Velocity Intake \| Steeda UD Pullies \| T56 6 Speed \| NGK-TR6 \| 03/04 Cobra Al Driveshaft \| 11 " DD SHD Perf. Clutch Kit \| Fidanza Flywheel \| Innovative LC-1 \| Venom VCN 1000 125 jet \| Walbro 255 \| 42 lb Injectors \| 90MM LMAF \| Detroit TruTrac \| Motive lightened 4.56 \| Moser 31 Spline \| BBS RGR Diamond Black \| P-Zero's 271rwhp / 265tq 11.7 A/F 376rwhp / 451tq 100 Shot no tuning

08-25-2005, 03:33 PM	#4 (permalink)
madmatt Traitor...lol Join Date: Sep 2004 Location: Lexington, SC Posts: 7,885	Nice article. I like it. __________________ RPMPlanets

08-25-2005, 07:10 PM	#5 (permalink)
tripleblack Senior Member Join Date: May 2005 Posts: 337	Sorry for the typos Sorry 'bout the typos. Should have proofed it. Also, hope everyone noticed that weight has a slot in the equation. A modification that increases power AND weight at the same time has a multiplier effect, ie, an aluminum drive shaft might increase power to the rear wheels and shave weight at the same time. Modifications like aluminum heads (I know, only for older cars, but still, the idea is that this formula works for all cars) would be a double hit, too. Just a reminder - if you use the formula to analyze a future mod, check to see if the mod will save (or add) weight. In fact, I noticed in his nitrous example that he didn't add the 20 pounds or so that the system would weigh. tripleblack

08-25-2005, 10:31 PM	#6 (permalink)
ModMotorRacer Modular Misfit Join Date: Dec 2004 Location: Iowa Posts: 329	Underneath all that technical crap is the same adage that has been around for years.....power vs weight...plain and simple. Its being over examined. Perfect example is an O/R X pipe compared to a stock H. 99% of your gain is because you just dropped 30lbs, not because you picked up 10rwhp. Or adversely those C&L freakin caveman club inlet tubes....those things weigh a ton compared to the stock plastic units..so any actual hp gains you get from them is instantly negated because of the extra weight. Its not rocket science, just common sense. Keep these 3 figures in mind when buying parts. 10rwhp= .10(one tenth of one second at the track) 10lbs sprung weight=.010(one hundredth of one second at the track) 10lbs unsprung weight= .10 These are not end all be all numbers but they are pretty damn close. Adam __________________ www.modularmisfits.com 98GT NA Auto...12.61@109 NMRA Mod Muscle #10

08-26-2005, 08:31 AM	#8 (permalink)
Shambles The Baninator! Join Date: Mar 2005 Location: Springfield, PA Posts: 2,652	Stchuckzored __________________ Chris "Shambles" Chamblee

11-11-2005, 12:39 PM	#9 (permalink)
stangb16a Junior Member Join Date: Aug 2005 Posts: 6	i would think measuring performance with a first gear acceleration number would not be that beneficial. there is a lot of thrust in first gear, but when your in third you really start to notice that all that hp isnt doing anything in a heavier car. i'd rather stick to power to wieght ratio numbers. less math too. but that is just my opinion.

12-15-2005, 11:08 AM	#12 (permalink)
ModMotorRacer Modular Misfit Join Date: Dec 2004 Location: Iowa Posts: 329	All I can tell you is that I am a bracket racer, so small increases in power and small increases/decreases in weight sometimes make a huge difference and sometimes don't. There are so many other factors that your "8th grade" math isn't taking into consideration. I think that its great that you have formulas worked out, but unfortunately there is much more to it than that. I don't use hp numbers to calculate anything which is the biggest mistake you can make. Especially manufacturer provided numbers. Weather, track conditions, track temp, wind, etc etc etc, are the only real numbers that matter. You don't race a computer or a calculater. __________________ www.modularmisfits.com 98GT NA Auto...12.61@109 NMRA Mod Muscle #10

12-15-2005, 11:39 AM	#13 (permalink)
Jack The Ripper Posts: n/a	So when lookin at the G's, Does that mean that 4:10's have the same performance gain as nitrous? Can anyone confirm this by when that have felt when upgrading one or the other?

12-16-2005, 02:10 PM	#18 (permalink)
ModMotorRacer Modular Misfit Join Date: Dec 2004 Location: Iowa Posts: 329	Altering gearing does affect weight though, and reciprocating weight too. A numerically higher gear has a thicker ring gear and a thicker pinion gear so it weighs more, and is more of a drag on the drivetrain even though it produces a higher torque multipication. Same with adding a 6 speed tranny , you have all the gearsets for the one more gear making it heavier. Like a C4 compared to a 4R70W, the C4 weighs less but is it really an advantage if I have a custom gearset (steep) 1-3 and a highway OD gear in the 4R70W even if the tranny weighs more? Like i said, its hard to just throw a blanket over everything and call it covered. Adam __________________ www.modularmisfits.com 98GT NA Auto...12.61@109 NMRA Mod Muscle #10

12-17-2005, 08:00 PM	#20 (permalink)
ModMotorRacer Modular Misfit Join Date: Dec 2004 Location: Iowa Posts: 329	"If you're just "estimating" something, thats ok, just keep in mind that the wilder the estimate, the more useless the outcome is likely to be." AMEN TO THAT __________________ www.modularmisfits.com 98GT NA Auto...12.61@109 NMRA Mod Muscle #10

07-27-2006, 10:30 AM	#21 (permalink)
GT_Johnny Junior Member Join Date: Jul 2006 Location: Yakima, WA Posts: 16	Man. Things sure have changed. Back in my day you just took out what you could to lose weight, increased Cubes where possible, got as much fuel in as you could and tried to make it breathe easy. Now a guy darn near needs to know calculus to figure out what to do. Any advice for a mathmatically challenged guy that just wants his car to accelerate quicker? I have too many cars to just dump thousands into the 'stang but I would like to make some minor changes here and there. I have replaced the stock mufflers with Flowmastahs and dropped in a K&N Filter. What would you guys reccomend next? Underdrive pullies? A Power Tuner? Thanks for the input and the forums.