Can someone ACTUALLY explain why you want low end torque?

This question is not as juvenile as it sounds - looking for a technical answer
Before I say anything else, this thread is purely for mature discussion, I have no desire to get in an argument with anyone.

Okay, so I've easilly read 50 threads on here and other forums trying to get an idea on a cam to go with. Inevitably, I've run across the following:
"You don't want a larger cam because you'll lose all that low end torque".

Honestly, this statement makes absolutely no sense to me. And I have yet to hear one person actually prove how this statement makes sense.

The point needs to be made right now that there is a difference between a car that is undrivable at low RPM's and a car that makes 'low' torque. This discussion is not about a crappily tuned car that bucks and surges. This is about why people freak out when they see a larger cammed car 'only' making 320 ft-lbs of torque at 2500 RPM...

In my mind, there are only 4 situations that pretty much completely describe all the possible driving scenarios.
1) Roll Racing
2) Road Racing
3) Drag Strip
4) Grocery gettin'

In each scenario, why does the torque you make below 3000 or really even 4000 RPM matter? Really?

I will say this, as an engineer, I don't necessarily care about the horsepower number per se, but I care intimately about the torque between the shift points - which just so happens to be horsepower.

I've asked this question because everyone seems to think that torque below 3000 RPM is important, and I just can't really see how its relavant (within reason).

I would think because you spend a lot more time at 3k and under than you do above. Not a lot of people would want to trade the performance they feel 90% of the time for a tad more up top. That's just my guess.

how i understand it, torque gets you going, hp keeps you going. if you dont have the torque to set you up, you'll be red-lining before you get anywhere

Okay, so I'll give my thoughts first on each of the possible driving scenarios.

1) Roll Racing: If you are below 3000 RPM, you are in the wrong gear and you will get raped. Done. (unless you are that guy on here a year ago or so who was dissappointed that he couldn't pass a Honda Minivan in 6th gear)

2) Road Racing: Look at the Experts - F1. They don't make more than about 233 lb-ft. But they rev 3 times higher than us, so they get 3 free gear reductions, and now that 233 lb-ft has turned into the equivalent 700 lb-ft in a 6000 RPM motor.

If you are road racing (truly racing), and you tell the engineer's that you are 'unhappy' with the low end torque (below 3000), YOU WILL GET LAUGHED AT AND FIRED. This is because you obviously do not know how to correctly choose gears. Having personally worked on powertrain/drivetrain development, I can back this up with all the math in the world.

Now we are getting to the 2 styles of driving that most people on here can relate to. These are the ones I expect to hear disagreement on.


3) Drag Racing: The issue here is that there are two forms, those hardcore members, and those still on street tires just having fun, wanting to beat their friends car. Well, I'll adress the hardcore members first. The only time you will spend below 3000 RPM is during the launch - maybe. The truth is, how many of the hardcore guys, leave at anything less than 3000 RPM? I have seen too many posts about guys leaving at 4500+RPM in the manuals. Here's a quote that says it all:

Quote: Originally Posted by Ben... I never leave below 4800rpm.. And the rpms never drop below 5k I think.. I just think that the car stock cam with plenty low end ... And giving some of it up might not be a bad thing.. My GTO is a DD and I hate it when the tires kick out a 30-40 mph under light accel(in the rain), I guess I'm weired and could care less about the low end.. Because the GTO will always have enough power to get me from A to B, and then when I want to race have all the top end I want.. It like having two cars in one LOL

The fact is, an extra 20 lb-ft of torque for the 0.2 seconds you might be below 3500 RPM in 1st gear is not worth it.

Now as for the guys with street tires, well, traction is going to be the issue. Even stock, 1st gear can be a spin fest for some people, so you are already at the limit of the tires, and every gear after 1st where you do have traction, you spend above 4500 RPM.

4) Grocery Gettin': I'll get to this one later, as I'm curious to hear what other people have to say first. Though personally, I find it funny when people see an enormous cammed car making more torque than I did stock - everywhere - and comment about how it must be absolutely no fun to drive...


Again, just looking for discussion here, I don't want to 'argue' with anyone.

That's not fair. I am exactly halfway between 3 and 4 !

Oh, cam. A smaller one will be more satisfying, unless you always drive in the 4500 RPM+ for the power. That said, you never lose torque with a big cam, you just don't feel the thrust of the big cam until the revs get rolling high. The Tq is up, you just feel the added power much much less in lower RPM, and after it revs, you feel the full burst, and think the low end was reduced.

Look at a dyno.

I would rather have gone smaller cam. A DD Goat wants the majority of the cam upgrade to go to low end. I would most definitely go a bit smaller next time. When I hit peak power, it is louder than Hell. I would rather have that power band pulled back a bit, to allow the cam to be specified for a better low-end increase. My large cam likes to be at 5000 RPM+.

I daily drive my GTO, and rarely race it in any kind of sanctioned venue, at most twice a year. I purposely picked a mild cam (224/230) because:

1 I got heads that would give me a good bit of top end anyway.
2 I like having low end around town.

Its really personal preference. Some people do not care about how the car performs below 4000 rpms. Many do. I personally take great enjoyment out of surfing the torque curve down low, and making the front end snap up when I hit the gas at 2k. It makes the car more fun to drive around town, because you make ample power low in the rpms, and you don't have to be flying to feel the power. You can just chill and poke around at the speed limit and goose the throttle all day.

To each his own.

I cant say I disagree with the OP.

Also the feeling of instant throttle response and having a ton of torque the instant you hit the gas, at any rpm, is a good one. You don't have to be racing to enjoy your car.

You first have to understand what torque is and how heavy our Cars are and why having bottom end torque and a whole lot of it is a good thing for our gto's.

I think the whole thing about no torque downlow with a big cam is over exagerated

I'll find out soon

Quote: Originally Posted by DJJONESIVS... You first have to understand what torque is and how heavy our Cars are and why having bottom end torque and a whole lot of it is a good thing for our gto's. I think the whole thing about no torque downlow with a big cam is over exagerated I'll find out soon

I think the OP understands what torque is.

The thing about big cams is average power. I have raced N/A GTOs and F-bodies with up to 50+ rwhp over me, and been neck and neck with them. Why? Well they have huge monster cams and I have a little tiny one that makes a lot of average torque, up until peak power where the big cams shine.

Same reason a V8 GTO with 400whp will beat a 4 banger civic with 400whp. Average power, and torque under the curve.

I had a 242/248 .624/.621 on a 111 cam in my GTO. Coupled with the 6 speed and stock gears it didn't like being in 6th less than 65mph. With 3.91's it was pure heaven. Loved that cam. You could drive it like a grandma, but watch out if you hit it and let her rev. Now I'm doing a twin turbo build, so that cam left for a more boost friendly 243/247 .624/.624 on a 115. I will say the old cam was horrible on gas mileage in town. I got 12-14 in town and 20-22 on the highway. Sounded cool as heck and got me 430rwhp in 110F Phoenix heat on 91 octane. I still have an idle vid in my sig from the old cam.

Well, during most of my day-to-day driving I spend the majority of the time below 2K, more often than not I'm upshifting at 1500. Low-end torque is also what allows me to enter a freeway in 6th gear and wind up to speed without downshifting and racing the engine (which still happens, but only because I love that brief rush from 40 to 80). Low end torque is a critical thing to me.

ditto,

I like being able to murge in 6th gear or cruise at 1500 rpms on the highway. This is likely why I will go with a maggie 1900 or even a 112/122 over any other power addded. I've driven hundreds of cars, and low end torque is much nicer for daily driving, (especially a m6) if you have an A4, just throw a converter and who cares about torque)

Ryan

Torque gets an object moving. The heavier the object, the more torque needed to get it to move. This is especially true on an uphill or in mud or bad traction areas. That is why all big rigs and even boats, have huge engines that make a lot of torque down low. Also why on a semi (big rig) they have a 10 - 15 speed gear box. It is the only way to keep the engine it is's power band, which on a big truck diesel is no more than 4K rpm at most.

The best way I can describe it is. I want it for shoving my GTO in 6Th gear at 30 mph and lugging it around town getting 25 mpg. People with street cars want it so you don't have a car that leaves a stop sign without falling on it face. Or without revving it up and slipping the clutch. I guess there is thousand reasons to want it. Good luck in whatever you get out of this discussion.

Quote: Originally Posted by bruceb... which on a big truck diesel is no more than 4K rpm at most.

Diesels also just don't have the ability to rev much over 4,000 rpm. Some newer ones can make it to 5,000. But Diesels just don't rev that high to begin with. Nothing to do with being out of the power band.

I read most of the replies, but for me having low end torque is just what I wanted. My cam is a mild one 224/581 w/113 lsa. I don't track my car so all of my driving is on the streets. And for a quick light to light "fun run" opens up all my power between first and third. I do however have upper end power too, but never have any use for it. First and second go by so fast that if I'm going to overtake a "competitor" it's done before 3rd. By that time I'm already over the speed limit and shutting down.

With all that being said, if you're into drag racing your car or doing any kind of of circle or twisties type of driving then you'll want all you can get. But then again, low end torque is good to have there too.

JMO......

ROK

I like the low torkz cos THESE r my ballz.

I need the torque for good launches without attracting attention when I am coming home from the grocery store. I have to get home before my ice cream melts.
On a serious note, I spend most of my time below 3k rpm and the response brings smiles to my face. I makes the car much more tractable around town.
The days of putting up with soggy bottom ends are over for me.

on a street car you spend most of your time below 3000rpm,unless of course you have steep gears and/or a big stall if your an automatic..
keeping the rpms down will result in better gas mileage,and less wear and tear on the car.. your motor will last longer ..
but we're talking about street cars here..drag or road racing is another matter..it's all about the intended use of the car..
personally i like a broad powerband,when i hit the gas at 1500rpm i like not having to downshift to get moving..

You can have all the big cam you want as long as your car is geared accordingly and have the right weight. F1 cars rev 3 times our redline, but they also weight what 700lbs ?, and their gears are insane. BMW V8 or V10 high rev engine, 8000-9000rpm redline, check their gears. for drag racing, you also want the biggest cam you can get that would allow the car to rev freely and live where the situation demands, 5000-6000rpm launches, rpm drops because of gear changes at around 5000rpm or so.

Road racing (unless is Road or America or any other super long race track), Daily duty street, or any other form of racing where your rpm window doesn't mean 5000-7000rpm, you'll be better off with more power under the curve, simply because that is what your gears/vehicle weight allows.

If you want power everywhere/anywhere in the powerband, get FI, cam accordingly to what you are going/want to do with the car. i couldn't do nothing but laugh at a 24x/24x cam in a goat with stock gears, racing Autox. i've seen it here (Toledo Airport), and well, let me tell you, the 450rwhp at 6200rpm didn't do shit agaisnt a bone stock GTO, same day, same race.

My car is an A/4 . makes great HP at high RPMs and makes MAD TQ at low RPM, in my case I am making around 480 RWTQ at only 2500 RPMs this is great because at hiway speeds
[ 65-70 MPH ] my car is only turning around 2100 RPMs. With just a slight touch of the pedel the car taks off like a JET. Give the pedel a firm push and it will drop down a gear and the car will launch like it was shot out of a Cannon . I drive a street car, it does not spend time at the track and I don't want to have to spin my motor to RED LINE to make good power

some people say big cams can't make big low end power. mine is a 653 / 648 243 / 248. pretty big to me

P.S.
a set of NITTOS 285s are on order right now

Quote: Originally Posted by ROKS ROKET... I read most of the replies, but for me having low end torque is just what I wanted. My cam is a mild one 224/581 w/113 lsa. I don't track my car so all of my driving is on the streets. And for a quick light to light "fun run" opens up all my power between first and third. I do however have upper end power too, but never have any use for it. First and second go by so fast that if I'm going to overtake a "competitor" it's done before 3rd. By that time I'm already over the speed limit and shutting down. With all that being said, if you're into drag racing your car or doing any kind of of circle or twisties type of driving then you'll want all you can get. But then again, low end torque is good to have there too. JMO...... ROK

Hey ROK, spec wise your cam might seem mild, but I have seen first hand what your car can do on the street. the name ROKET does fit .

DIZZY

Quote: Originally Posted by JJD49... Hey ROK, spec wise your cam might seem mild, but I have seen first hand what your car can do on the street. the name ROKET does fit . DIZZY

Thanks Diz, but next to your car I felt like I was standing still, lol, lol..............

I think the torque down low argument is much more pertinent to A4 cars drag racing then M6 cars. As you said to go fast in an M6 most of us are launching at 4k+. However in an A4 even alot of the fast cars are only loading the car up anywheres from 1500 to 2500 RPM. This is where the auto cars would need that low end torque to pull our massive weight through the RPMs into the powerband. As well as in a surprise roll race the A4 might get stuck down low where as an M6 can be quickly into the powerband regardless.

This is also why M6FTW!! thats just my .02cents.

Quote: Originally Posted by BlueGoat06... You can have all the big cam you want as long as your car is geared accordingly and have the right weight. F1 cars rev 3 times our redline, but they also weight what 700lbs ?, and their gears are insane. BMW V8 or V10 high rev engine, 8000-9000rpm redline, check their gears. for drag racing, you also want the biggest cam you can get that would allow the car to rev freely and live where the situation demands, 5000-6000rpm launches, rpm drops because of gear changes at around 5000rpm or so. Road racing (unless is Road or America or any other super long race track), Daily duty street, or any other form of racing where your rpm window doesn't mean 5000-7000rpm, you'll be better off with more power under the curve, simply because that is what your gears/vehicle weight allows. If you want power everywhere/anywhere in the powerband, get FI, cam accordingly to what you are going/want to do with the car. i couldn't do nothing but laugh at a 24x/24x cam in a goat with stock gears, racing Autox. i've seen it here (Toledo Airport), and well, let me tell you, the 450rwhp at 6200rpm didn't do shit agaisnt a bone stock GTO, same day, same race.

i've seen it too where someone bought a cam with a slide ruler (they still make those?) and got their butt handed to them by someone with a smaller cam with that enigmatic "power under the curve". i guess that's why i put my trust in the judgment of Ed Curtis to grind a cam that fits my driving style. sometimes experience wins over "science"

Quote: Originally Posted by FSAE_Junkie... This question is not as juvenile as it sounds - looking for a technical answer Before I say anything else, this thread is purely for mature discussion, I have no desire to get in an argument with anyone. Okay, so I've easilly read 50 threads on here and other forums trying to get an idea on a cam to go with. Inevitably, I've run across the following: "You don't want a larger cam because you'll lose all that low end torque". Honestly, this statement makes absolutely no sense to me. And I have yet to hear one person actually prove how this statement makes sense. The point needs to be made right now that there is a difference between a car that is undrivable at low RPM's and a car that makes 'low' torque. This discussion is not about a crappily tuned car that bucks and surges. This is about why people freak out when they see a larger cammed car 'only' making 320 ft-lbs of torque at 2500 RPM... In my mind, there are only 4 situations that pretty much completely describe all the possible driving scenarios. 1) Roll Racing 2) Road Racing 3) Drag Strip 4) Grocery gettin' In each scenario, why does the torque you make below 3000 or really even 4000 RPM matter? Really? I will say this, as an engineer, I don't necessarily care about the horsepower number per se, but I care intimately about the torque between the shift points - which just so happens to be horsepower. I've asked this question because everyone seems to think that torque below 3000 RPM is important, and I just can't really see how its relavant (within reason).

by your sig i see you just have bolt ons..drive a car with a big cam around town,in traffic,etc.,it's not much fun,no matter how good the tune is..

Quote: Originally Posted by ROKS ROKET... Thanks Diz, but next to your car I felt like I was standing still, lol, lol..............

Welcome. a lot of people still feel that small or mild cams can't make good power. They are dead wrong on that one. Just like the one's who say big cams can't make good power down low, They have to be at 4500 RPMs or more. You need the RIGHT cam to fit your mods or bolt on's . you can't just pic a spec for a cam without thinking about your current or future mods

Quote: Originally Posted by 66deuce... by your sig i see you just have bolt ons..drive a car with a big cam around town,in traffic,etc.,it's not much fun,no matter how good the tune is..

It would have been no fun to drive if I kept the tune in it that shop that installed it did. THEY SUCK, car would buck, stall, shutter , you name it
Found one of our Sponsers { Mongillo Motors } and they did the rest

This car is a blast to drive anywhere and anytime. around town, on the hiway, out of state, even to go get a quart of milk down the street. still get 25 MPGs on the hiway , around 17 city. no stalling, surging, bucking. Drive it easy, drive it hard. No Problems.. several people on this site can back me up on that one. Go for a ride in it and find out for yourself. Got even better after the install of a Procharger and Speed Density tune

I think there is a certain mentality with big cams. Or should I say bragging rights? I'm not very fluent with cams at all, and at some point want to get a very mild (small) blower cam that's more fi friendly, but by no means do I want a huge cam. For one, I don't want the sound of one on my car, hearing someone elses on youtube or on the street, great, but not for me. I like my little wag the stock cam gives the goat now, that's plenty.

But anyway, good info in this thread and opinions. I absolutely love the torque down low, hence why I have a maggie and not a procharger. There are times when I may take the goat to work (~60 miles round trip) that I don't get to romp on it any except to 4 or 5k max (and then probably don't even hit boost). There is too much traffic and idiots in the way tootling along in the fast lane because they have to turn left 10 miles up the road. The gear rowing and passing ability to get through traffic at a moments notice at 2500k makes all the traffic bs worth it. Always instant power, even out of boost. I want to keep it that way too...

I see the different sides of the big cams, def a lot of misinformation out there too.