93' camshaft question

[wahlstrom1]

Should have pointed out.....Those numbers are RWHP/TQ numbers on a mustang dyno, long bed 2wd 5 spd

1/4 mile times:

(Best N/A #'s) ET 14.304 @ 90.74 mph / MPH 94.8 / 60' 1.851 sec.

(Best on the bottle) ET 13.427 @ 100.78 / MPH 100.8/ 60' 1.933 sec.

 

[Bob Ayers]

From Ford.........................

 

[AllanD]

Those numbers sound remarkably like a typical OHV 4.0 with peak airflow point moved up 500-1000rpm, as Will, AllanD, and myself suggested. Quite the opposite of what the OP appears to need. Not that a cam is a bad change, but it does nothing to improve low RPM airflow.

Like I said THE SAME torque just at a higher rpm and considering it's a truck with too tall gears or too tall tires for the gears the SAME torque at a HIGHER rpm will do NOTHING to make the situation better infact it'll exaggerate the situation that the OP is already complaining about.

So Once again, another cam will NOT "make him happy"

it WILL make the situation worse.

And I'm gettin' tired of having to repeat myself to people who have
their little idea but refuse to listen to simple physical reality.

So I'm terribly NOT sorry to confuse anyone with facts.



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[Tee Rev]

You guys kill me!!

The #'s Andrew posted are at the wheel, not at the crank. I'll let the mathematicians figure out the Crank #'s


I'll keep my advice to PM's from now on, you guys are just too much!

 

[Bob Ayers]

Like I said THE SAME torque just at a higher rpm and considering it's a truck with too tall gears or too tall tires for the gears the SAME torque at a HIGHER rpm will do NOTHING to make the situation better infact it'll exaggerate the situation that the OP is already complaining about.

So Once again, another cam will NOT "make him happy"

it WILL make the situation worse.

And I'm gettin' tired of having to repeat myself to people who have
their little idea but refuse to listen to simple physical reality.

So I'm terribly NOT sorry to confuse anyone with facts.



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Must be a Canadian thing!!!

 

[fastpakr]

You guys kill me!!

The #'s Andrew posted are at the wheel, not at the crank. I'll let the mathematicians figure out the Crank #'s


I'll keep my advice to PM's from now on, you guys are just too much!

I don't think anybody confused the two. Obviously those are wheel numbers. The point is that you're now making your peak numbers well AFTER the factory 4.0 did. Instead of helping the problem of low end torque, you've made it worse. Your own numbers clearly demonstrate that. Not sure where the confusion lies.

 

[Bob Ayers]

I'll let the mathematicians figure out the Crank

Yes, you seem to have trouble with basic math!!!!!

 

[Tee Rev]

I don't think anybody confused the two. Obviously those are wheel numbers. The point is that you're now making your peak numbers well AFTER the factory 4.0 did. Instead of helping the problem of low end torque, you've made it worse. Your own numbers clearly demonstrate that. Not sure where the confusion lies.

Really!!

Assuming a conservative 15% loss through the drive line, 198 rwtq at 1700 = 232.9 ft/lbs at the crank. 219 rwtq at 3510 = 257.6 ft/lbs at the crank.


Can you please show me where I hurt low end torque?



BTW Bob, you may want to keep your comments to yourself! I've probably got more American heritage than you!! Scary isn't it!

 

[fastpakr]

15% isn't remotely 'conservative'. While it may be common place to make up convenient numbers to explain driveline loss, that's a tremendous amount of power to vanish into heat.

Even assuming 15% is accurate, go look where the factory 4.0 was at 1700RPM. North of 220. As good, if not better than yours. You have not improved low end torque in the slightest. You do have slightly better numbers on the top end, but again - that is not what the OP is looking for.



***** Both you and Bob need to stop the insults. Consider yourselves warned. Keep this a tech discussion. ****

 

[wahlstrom1]

Even if he is only making stock power at lower RPM, the higher rpm torque will pull harder on the under geared vehicle as you'll be pulling the same rpm's longer due to the effectively higher ratio. IMO is it the ideal setup? No....gear's rock! But it can't hurt, I know when I had the OP's setup I wish I had more power in the high end because I spent a lot more time the due to the gearing issues.

 

[AllanD]

Even if he is only making stock power at lower RPM, the higher rpm torque will pull harder on the under geared vehicle as you'll be pulling the same rpm's longer due to the effectively higher ratio. IMO is it the ideal setup? No....gear's rock! But it can't hurt, I know when I had the OP's setup I wish I had more power in the high end because I spent a lot more time the due to the gearing issues.

Once you get it rolling and into the torque band, yes.

the rub is we are discussing 4x4 trucks and torque below the peak
is VERY important particularly when offroading.

I'm highly concerned with power in that part of the torque band,
not because I offroad, but because I drive more miles towing in
a year than most people here do commuting each month.

Offroading is subject to the same needs.

But torque way down low is less about acceleration than it is about precise control of the vehicle going over obstacles.

Did you ever have a boat that took FOREVER to get up on plane
but once it was there it was "fine", frankly unless you got laid in that boat you probably don't have fond memories of it.

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[Will]

That's a quick 91mph. A more usual low 14 (I used a 14.2 when I entered it into my super-secret VBasic program) would be 100mph. 91mph is 200hp net and a typical 3000# car would run a mid 15s. Completely believable. The truck is set up exceptionally well.

Otherwise, I completely agree with Fastpakr and AllanD in this. Gear the truck properly. Showing me 197ft# at 1700rpm--and giving you the 15% benefit of the doubt--you are still pretty much on the stock Ranger torque curve. And a stock Ranger 4.0 with 3.73s sux with 33" tires.

 

[Tee Rev]

Thanks Will, I attribute the low mph to the brick like shape of my truck.
If you run the 1/8th mile #'s through your program you'll see a slight increase (9.03 @ 76 mph) & although I have managed to run back to back 14.37's @ 95 mph, usually the mph is 91-92
Something else to take into consideration is the effective altitude. In Calgary The effective altitude can range from 4500' to 6500', at these altitudes the engine is only able to produce 85- 90% of it's power. 200hp here would be at the very least 220 at sea level.

Also, I'm not in disagreement about the gear issue at all. As a matter of fact, I have an 06 R/C 4.0L 4x4 that has 31's & 3.73's that I'm installing 4.56's in as soon as possible. It probably doesn't need them, but I know that bigger tires are in it's future

My intention was only to answer what I read as the question.

But I do have something to add,

Regarding the driveline loss; Friction is only part of it, the mass of the driveline is also a factor. There's close to 300#'s that link the flywheel to the rollers on the dyno(transmission, diff & wheels), Considering that the test only lasts a few seconds, it takes a considerable amount of power to accelerate this mass through the test range. The power required to do this isn't going to make it to the rollers on the dyno, & therefore is lost.

No convenient numbers, just simple physics.


AllanD is concerned with possible drivability issues with this cam. You definitely don't want a cam that has a tendency to make the engine surge while you're trying to tippy toe through rocky terrain. The 422 is a very mild grind, it still pulls 20 in/hg of vacuum at an idle of 750rpm & has only the slightest lope. By 1000rpm under very light throttle it pulls 23 in/hg of vacuum & is absolutely smooth.

Here is a link to a video of me doing a couple 1/4 mile test runs on a dyno shortly after swapping the cam. This is with the factory ECU & stock program.

Enjoy!
http://members.shaw.ca/tomak/quartmile.wmv

 

[AllanD]

Regarding the driveline loss; Friction is only part of it, the mass of the driveline is also a factor. There's close to 300#'s that link the flywheel to the rollers on the dyno(transmission, diff & wheels), Considering that the test only lasts a few seconds, it takes a considerable amount of power to accelerate this mass through the test range. The power required to do this isn't going to make it to the rollers on the dyno, & therefore is lost.

No convenient numbers, just simple physics.

Just simple physics? Yeah, that you have an incomplete grasp of.

No power is actually "lost" through driveline mass, however it affects the measurement of the power precisely as you describe.
But the power didn't actually go anywhere.

and the apparrent loss isn't nearly as great as you think it is.

you've probably been misled by others talking up their stuff the same way.

Just between you and me the picking at your posts isn't nearly what it would be if you have waved a "red flag" like saying (for example) that you had a "3/4 race camshaft" try that one sometime and the fecal material will really splatter as it hits the rotary ventilation device.

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[colinrmitchell]

"It just doesn't work out!"