2 Questions

[black mamba1]

1. What exactly is the torque advantage in racing? The Gen 3 Viper has a torque advantage over the Z06 and the latest 911 TT, but loses from 0-140 mph w/ most drivers. But I constantly see guys w/ nitrous and Roe s/c talk about the torque advantage, forgive me is I am missing something here....there are lower torque cars giving the Vipers fits.

2. If you could pick 700 rwhp, 800 rwhp, or 900 rwhp...what would you pick considering drivability and traction, and usable horsepower issues. Most of my races are from the dig or from 60-150 mph. For those of you who say I have asked this question 1.6 million times...well, hell...what can I say, you're right?

One reason I ask is that MikeR used to kick IllSmq's ass in the 1/4 mile B4 MikeR was s/c due to traction problems for Illsmoq (I think)...and apparently is still kicking his ass! (Sorry Illsmoq, I couldnt resist!)

BTW MikeR and IllSmoq..I am going back to Cali, Cali, Cali..I am going back to Cali...hmmm just to smoke you!(after boost of course!)

 

[ILLSMOQ]

1. What exactly is the torque advantage in racing? The Gen 3 Viper has a torque advantage over the Z06 and the latest 911 TT, but loses from 0-140 mph w/ most drivers. But I constantly see guys w/ nitrous and Roe s/c talk about the torque advantage, forgive me is I am missing something here....there are lower torque cars giving the Vipers fits.

2. If you could pick 700 rwhp, 800 rwhp, or 900 rwhp...what would you pick considering drivability and traction, and usable horsepower issues. Most of my races are from the dig or from 60-150 mph. For those of you who say I have asked this question 1.6 million times...well, hell...what can I say, you're right?

One reason I ask is that MikeR used to kick IllSmq's ass in the 1/4 mile B4 MikeR was s/c due to traction problems for Illsmoq (I think)...and apparently is still kicking his ass! (Sorry Illsmoq, I couldnt resist!)

BTW MikeR and IllSmoq..I am going back to Cali, Cali, Cali..I am going back to Cali...hmmm just to smoke you!(after boost of course!)

oooooh........ MikeR kicks my ass cause I can't drive.

he was still kicking my ass last weekend......however If he will man up and run me this weekend I think we may see differnet results

coming to Cali too LL-slow-Snake??? ...........your the type of guy that has no idea that that car that the silver viper that's gonna put car lengths on you has ILLSMOQ on the rear. catch my drift? cause I'm that type of guy.

 

[ILLSMOQ]

oh and the way I understand it....torque is a measure of the force aaplied to get somthing moving and horsepower is a measure of how fast it accelerates

.....actually I have no clue, I just know that I like to have a lot of both

 

[black mamba1]

Re: Two Questions

I see u r up on your LL!

You guys are having wayyy too much fun out there not to share! Yeah, even in my slow n/a set up it would be a blast to come out there and hang out (and get blown away by both of you!) for a while.

The reason I ask about the torque is b/c lets say I have 528 rwhp and 537 ftlb of torque, and my buddy has 500 rwhp and 560 ftlb of torque, who has the advantage in the 1/4 mile? And why do the nitrous guys have SO much torque? And does all that torque help them over their hp?

Lastly, the reason I ask about the different hp levels is b/c I read a post on here where a guy was at 640+/- rwhp, but detuned it down to 587 rwhp due to throwing codes. But he actually got better 1/4 mile and drivability. BUT, he was driving a Mustang. I think I will try to stay around 775-830 rwhp, and hopefully I will be able to still keep the car pointed straight!

 

[Nader]

Re: Two Questions

The way I have always thought about it is - torque is what creates the initial momentum in the Viper. It is what will put you back in your seat upon stepping on the gas. Nail the throttle at 3000 rpm in second or third and that initial "jump" into exceleration is the easiest way to discribe it.

The Viper with all the torque, so long as it is able to put it to the ground, will jump on most every car due to the high torque. I have raced a modded Z06 where I would get the intial jump everytime but he would run me down with the higher rpm and gearing.

It isnt easy to put all the torque in the Viper to the ground from a dead stop due the the limitations in traction.

My $0.02. I am sure someone has a more scientific discription...

I see u r up on your LL!

You guys are having wayyy too much fun out there not to share! Yeah, even in my slow n/a set up it would be a blast to come out there and hang out (and get blown away by both of you!) for a while.

The reason I ask about the torque is b/c lets say I have 528 rwhp and 537 ftlb of torque, and my buddy has 500 rwhp and 560 ftlb of torque, who has the advantage in the 1/4 mile? And why do the nitrous guys have SO much torque? And does all that torque help them over their hp?

Lastly, the reason I ask about the different hp levels is b/c I read a post on here where a guy was at 640+/- rwhp, but detuned it down to 587 rwhp due to throwing codes. But he actually got better 1/4 mile and drivability. BUT, he was driving a Mustang. I think I will try to stay around 775-830 rwhp, and hopefully I will be able to still keep the car pointed straight!

 

[MikeR]

I really dont know much at all. I will say that as we all know, one of the big advantages to the Z06 is WEIGHT and GEARING. Ive started to see this with my last few mods as a benefit. The 3:33's and lighter rotors changed the car drastically.

Im actually going to try and get a guy I met to race me. He has a 800 rwhp Paxton GTS. I want to see what hapens with his advantage being torque and power, but mine being posibly better traction and lighter.

Anyways, after driving my car, Im used to power, yet its still scary fast. Could I use more...sure
But I think if you dont have crazy money to spend on a TT and all the upgrades, a Paxton with 700 rwhp is perfect setup, lighten the cars rotatonal mass with things like lighter wheels and rotors, get some gears and you will be almost unbeatable. How often do you really race from a stoplight. For me, not often, rare to line up on front line against another fast car and I worry about Cops. But its common to come across someone who wants to play on the freeway , be it a bike or car. As much as I like to drag race, it is actually rare that I get to the drag strip. Also, if I was serious, I would need to build up more stuff in the driveline and run 18's with slicks or drag radials. I dont think you want to do that. So when I race I always get someone to follow me to freeway, its safer and its in the Vipers sweet spot, 3rd gear rolls.

So with a nice balance of Hp/Tq/weight and gearing you can have a rocket, that beats cars with more tq or hp.

There have been some Mustangs challenging me and one I ran the other day, about 680 rwhp/600 rwtq, but he weighs 3800lbs. I walked away from him as if it was a 500 rwhp Viper.

I know I havent said anything technical, just alot of rambling.... But dont worry about the tq/hp thing.
Just get a Paxton, tune it right and get stoptechs, and a quaife with 3:33's. You wont lose to anyone in your state, come to Cali and it will be a different story......

 

[GR8_ASP]

Uh oh. Here comes an engineer.

The problem is that you are only referencing the peak torque ot the peak power. If you used a torque curve instead there would be no discussion about power versus torque as they are mathematically related. Only a torque curve or a power curve is necessary, not both.

But the real question you are asking is it better to have a torque curve with the peak at a low rpm (aka Viper) or with a high rpm peak (aka Z06). It does not matter as long as each has gearing aligned with its band. Launch is impacted as output speed is zero or very low and thus wheel spin speed is impacted. In general, for a properly sorted vehicle with equal peak power, the one with a wider, fuller torque curve will be faster. That is at points away from the peak power speed it will deliver more power (same argument with torque).

Note that at any speed the acceleration capability of a vehicle is related to the maximum torque available at that engine speed multiplied by the effective gear ratio of the trans, diff and tires. Change gears, go to a new point on the torque curve and the results change accordingly.

As to the nitrous question nitrous effectively adds fuel and oxygen at a given flow rate (not in synch with engine speed). So it increases the power by a near constant value through the rpm band (ignoring volumetric efficiency effects). That means it has a linear reduction in added torque as the engine speed increases.

 

[black mamba1]

Uh oh. Here comes an engineer.

The problem is that you are only referencing the peak torque ot the peak power. If you used a torque curve instead there would be no discussion about power versus torque as they are mathematically related. Only a torque curve or a power curve is necessary, not both.

But the real question you are asking is it better to have a torque curve with the peak at a low rpm (aka Viper) or with a high rpm peak (aka Z06). It does not matter as long as each has gearing aligned with its band. Launch is impacted as output speed is zero or very low and thus wheel spin speed is impacted. In general, for a properly sorted vehicle with equal peak power, the one with a wider, fuller torque curve will be faster. That is at points away from the peak power speed it will deliver more power (same argument with torque).

Note that at any speed the acceleration capability of a vehicle is related to the maximum torque available at that engine speed multiplied by the effective gear ratio of the trans, diff and tires. Change gears, go to a new point on the torque curve and the results change accordingly.

As to the nitrous question nitrous effectively adds fuel and oxygen at a given flow rate (not in synch with engine speed). So it increases the power by a near constant value through the rpm band (ignoring volumetric efficiency effects). That means it has a linear reduction in added torque as the engine speed increases.

Uh...uh.....ok.

Actually I do get it. So I would imagine (w/out doing a search) that the guys w/ Roe superchargers should see more torque on average at a given rpm than the Paxton guys. Which explains why a 650 hp Roe will beat a 650 hp Paxton.

 

[black mamba1]

Re: Two Questions

The way I have always thought about it is - torque is what creates the initial momentum in the Viper. It is what will put you back in your seat upon stepping on the gas. Nail the throttle at 3000 rpm in second or third and that initial "jump" into exceleration is the easiest way to discribe it.

The Viper with all the torque, so long as it is able to put it to the ground, will jump on most every car due to the high torque. I have raced a modded Z06 where I would get the intial jump everytime but he would run me down with the higher rpm and gearing.

It isnt easy to put all the torque in the Viper to the ground from a dead stop due the the limitations in traction.

My $0.02. I am sure someone has a more scientific discription...

Yeah, the Viper has alway had monstrous torque, and monstrous wheel spin! I understand what you mean when you say torque is how hard the Viper pins you back in the seat...which would be acceleration. I think the way you described it is the best I have heard so far!

 

[j-rho]

GR8 ASP's concept is how you translate the output of your car's engine into the same form they use for jets, pounds of thrust.

If anyone cares to post a dyno chart of their car, along with that of a competitor's, I can graph it out for you. Gearing and tire sizes, if non-stock, are helpful too. Based on that info I can suggest the best starting speed for one car or another in a roll-on race.

 

[Viper X]

black mamba 1,

GR8_ASP did a good job.

1 - Here is a simple application of why torque is important in road racing:

On one of our local tracks, Willow Springs, I can drive the entire track in 3rd and 4th gears and get very good (low) lap times due to the high / broad torque band or low end grunt of my modded 2001 GTS (600 fwhp / 625 fwtq).

I can come out of corners in 3rd gear at lower rpm and still accelerate as fast as my competition does (while they are in 2nd), then pull by them as my engine speeds up. When I shift into 4th, the engine has the grunt to pull hard at low rpm and I continue to acclerate as fast or faster than they do at the same point in the power band. Again, as rpms go up, the car continues to pull harder and harder (towards peak hp). You have power at both ends of the band with the Viper. Part of the reason that it's such a beast on a road course. You will need to learn how to drive it well though to be able to effectively apply the power.

When runing against Vettes, they are almost always shifing up and down to try and stay in their power band. Shifting takes time and the car is not accelerating when you are shifting. The more you have to shift to get around a track (generally with our transmissions anyway), the slower your lap times.

2 - What would I pick, 900 peak rwhp over the others. But I would want to see the power band (dyno) too and look at the torque curve. My 925 rwhp Paxton car makes about 630 rwtq at 3000 rpm, which is more than enough. It goes up fast from there and peaks at 810 or so rwtq and holds almost all of this torque to my 6500 rpm redline. You can get most of the power to the ground with mods and some very disicplined driving and throttle modulation.

My .02 cents.

Dan

 

[Burntrubber]

All things being equal the car with more torque will win. That said all things being equal the car with more horsepower will win. But we have to look at weight, gears ratios combine with hp/tq. Remember the the Z06 had less torque made made alot of power up top and was geared to take advantage of that. Torque is what will pull you from a stop, or going aound that corner onto the straight away. torque is more brute force, say mike tyson, while hp gives a smooth linear build. thats why ROE cars break the tires loose when you slam the gas pedal, and paxton car build up that power and allow you to put it to the ground.

 

[wallbanger]

You guys are all torque!

 

[wallbanger]

For those of you will little knowledge about how a car works like myself then Howstuffworks is the ultimate website complete with moving diagrams... it has a nice section on torque

Howstuffworks "How Force, Power, Torque and Energy Work"

 

[j-rho]

For those that learn from pictures/graphs-

Below is a thrust-in-gear chart comparing the values for a 2008 SRT-10 and 2006 C6 Z06. I got lucky and found a dyno pull of each car, stock, on the same dyno.

Basically, the higher the line on the Y axis (longitudinal "G" force), the harder the car is accelerating in that gear, at that speed. Generally, tires put a soft ceiling on things in first and second gear - .7g on street tires takes a nice clean surface and good conditions.

What I see from this graph is that the SRT and Z06 have similar maximum speeds in each of their gears - the difference in gearing is made up for by the difference in redline. I notice that up to about the midpoint in each gear, the Z06 has a strong advantage, and in the upper half of the gear, the SRT has the advantage.

Thus, if I had a stock SRT and was picking a race from a roll against a stock Z06, I would want to pick a speed that started me at the beginning of my "advantage" range. In this case, that would be 65-70 for a 2nd gear race, or 90mph for a third gear race. Conversely, the Z06 would be better from a 40-45mph roll, since first gear would be hard to use.

If you drop a line straight down from the end of a given thrust curve to see where you fall in the curve of the next gear, I notice that the SRT-10 is basically always drops down to where it's better. The Z06 is better off when "caught in the wrong gear", but if you're on a racetrack or something, the Viper should pull harder everywhere.

Below the graph is a link to the spreadsheet I put together that makes the graphs. If you like, play around with some of the cells on the "Data" sheet to see how it affects things on the graph. For instance, the second graph I posted has only one cell changed - the Viper's rear end ratio upped to 3.42.

Enjoy!

You must be registered for see images

http://www.jrho.com/viper/thrust.xlsx

You must be registered for see images

 

[black mamba1]

black mamba 1,

GR8_ASP did a good job.

1 - Here is a simple application of why torque is important in road racing:

On one of our local tracks, Willow Springs, I can drive the entire track in 3rd and 4th gears and get very good (low) lap times due to the high / broad torque band or low end grunt of my modded 2001 GTS (600 fwhp / 625 fwtq).

I can come out of corners in 3rd gear at lower rpm and still accelerate as fast as my competition does (while they are in 2nd), then pull by them as my engine speeds up. When I shift into 4th, the engine has the grunt to pull hard at low rpm and I continue to acclerate as fast or faster than they do at the same point in the power band. Again, as rpms go up, the car continues to pull harder and harder (towards peak hp). You have power at both ends of the band with the Viper. Part of the reason that it's such a beast on a road course. You will need to learn how to drive it well though to be able to effectively apply the power.

When runing against Vettes, they are almost always shifing up and down to try and stay in their power band. Shifting takes time and the car is not accelerating when you are shifting. The more you have to shift to get around a track (generally with our transmissions anyway), the slower your lap times.

2 - What would I pick, 900 peak rwhp over the others. But I would want to see the power band (dyno) too and look at the torque curve. My 925 rwhp Paxton car makes about 630 rwtq at 3000 rpm, which is more than enough. It goes up fast from there and peaks at 810 or so rwtq and holds almost all of this torque to my 6500 rpm redline. You can get most of the power to the ground with mods and some very disicplined driving and throttle modulation.

My .02 cents.

Dan

Great info Dan, Thanks! How useful is your first and second gears with that kind of torque at such low rpm?

 

[black mamba1]

Those graphs really tell the story! Thanks for illustrating them. It seems like the 3:42 really wakes up the Gen 4 SRT..makes u wonder why they dont come from the factory like that.

 

[GR8_ASP]

Here are a few very old graphs I made. When analyzing a vehicles potential I always translate into maximum thrust. You can the adjust for maximum tire capabilities by clipping the max thrust in the lower gears. Note these were both made from real dyno run data.

This also shows the effects of differing gear ratios. You can see how some ratios are better than others for specific speed ranges. But, of course, there in no panacea.

 

[plumcrazy]

i bet tom F&L has an answer to this question. i kinda remember him talking about this one day a long time ago

 

[black mamba1]

Are the sharp dips in the graph indicative of shift points? Great graph!

Also, it seems the 3:55 and the 3:73 have an advantage until about 110 mph. I dont follow the second graph. I am not sure what it is trying to indicate.

 

[commonsense]

Horsepower IS torque........times RPM divided by 5252. It doesn't matter if you have an engine making 250 lbs of torque at 10,000 rpm or an engine making 500 lbs of torque at 5000 rpm. They both are making 476 hp. However, a torquey motor is rarely caught out of the power band. This is an advantage on the street, especially going fast on unfamiliar roads or for an impromptu drag race. On a racetrack, where you know where you're going, I don't think it makes much difference for a skilled driver. Horsepower is horsepower and the two engines, in the example above, should perform pretty similarly if those are their respective redlines.

 

[mykes]

It's simple hp sells cars,torque wins races.

 

[NK BREKR]

Nevermind what I was going to say.

 

[cheryl mccally]

Here are a few very old graphs I made. When analyzing a vehicles potential I always translate into maximum thrust. You can the adjust for maximum tire capabilities by clipping the max thrust in the lower gears. Note these were both made from real dyno run data.

This also shows the effects of differing gear ratios. You can see how some ratios are better than others for specific speed ranges. But, of course, there in no panacea.

Thank you Gr8 ASP for the graphs and the explanation. Very good stuff! I really like the second graph where it shows exactly where the shift point would be in each gear for max output. Very useful info at the track! Lots of racers shift into 5th on some of the straights, but from your graph, apparently there's no advantage until you reach 150+. Is the time graph important in that scenario?

 

[cheryl mccally]

Never mind the previous stupid question, 4th into 5th gear works the same as all the other sweet spot shift points and you need to shift into 5th at 118 to max engine output.

 

[plumcrazy]

from 4th to 5th at 118 ?