MTX Cams in ATX 3.2L

[kconnor]

Contemplating installing higher performance cams in my ATX. It has a 3400 rpm stall converter, BBB, ported runners, 73mm MAF and a Hypertech chip. I don't want to lose too much throttle feel at the low end. Is there any advantage to using the MTX cams in the 3.2L or should I go with a Stage 1 or Plus 10 type grind.

 

[93rev2sev]

lesee...the 3.0 cams have .03" extra lift, IIRC.

Extra lift=more flow overall and lower intake air speeds.

The reason for less lift in the ATX cars has not been completely determined...to my knowledge. Some say that it was to save the transmission. Some say it was to maintain low end torque.

Since you have ported runners, BBBs, big MAF...the air will be a little bit more willing to enter the engine...since the displacement was not increased with the airflow capabilities, intake airspeeds WILL go down slightly because of the extra flow. Add in some higher lift cams and well...the intake airspeeds will go down even more...while total air volume will go up.

If I had to guess...your fuel economy will go down slightly and low end torque will be hurt...but not enough for you to feel it...especially with your high falutin' TC.

On the plus side, at higher RPMs, your engine will DEFINATELY be able to use the extra charge and you will probably see a usable increase in power.

 

[Shoaz]

The reason for less lift in the ATX cars has not been completely determined...to my knowledge. Some say that it was to save the transmission. Some say it was to maintain low end torque.

I think it was just to keep the rated chp at 220hp so that it wouldn't be higher than the MTX or the Mustangs at the time.

 

[AREA 91]

I recomend changing cams. I did it before, and thought I noticed a difference. Also do your valve stem seals while you are in there.

 

[93rev2sev]

I think it was just to keep the rated chp at 220hp so that it wouldn't be higher than the MTX or the Mustangs at the time.

Respectfully, I don't agree.

In 93, the Taurus was the number one selling sedan in the world. You will have a hard time convincing me that Ford said "no, thank you" to free horsepower...ever...let alone on it's flagship platform.

Just my opine...


Edit...to give you a little idea of what I imagine happened...

Ford bean counter: So,the 3.0 cams that are slated to go into the new 3.2 are predicted to cause an uptick in "in-warranty" ATX fail rate of .8%. The predicted increase in sales revenue due to the extra horsepower will be .78%. Therefore, Ford Motor Company will lose approximately $42,216 by using the exisiting cams. Having Yamaha grind a different cam will only cost $42,215. It's clear to us bean counters that the 3.2 should have new, lower power intake camshafts.

 

[SeanMc]

I agree with Eric. If you were right, then why did they give the ATX 15 more torques?

To the OP, everything you have sounds great...except for the 73mm MAF, and the Hypertech chip. Go get an 80mm out of the junkyard, and go get a pro tune with either SCT or TwEECer. TedB and Axianator seemed to have disappeared, or else I'd recommend getting an LPM from them.

 

[93rev2sev]

I agree with Eric. If you were right, then why did they give the ATX 15 more torques?

So the ATX would not be SLOWER than the MTX. Due to an increase in displacement?

 

[kconnor]

The 3.0L is rated at 220bhp @ 6200, 200rpm higher than the 3.2L. The 3.0L’s torque peak is 800rpm higher than the 3.2L but 15lb-ft less.
Relative to the MTX cam I’ve read that the ATX intake lobe has 4° less duration, the intake chain ****** is advanced 4 crankshaft degrees and that exhaust cam is advanced 4°. I can see why Ford chose to do this for the 3.2L. These differences plus the increase in displacement would tend to get the 3.2L on the cam earlier, which is useful for an automatic. The MTX intake lobe is marginally hotter than the ATX’s and this was probably done to keep the 3.2L from exceeding the 3.0L’s horsepower rating.
With a slight loss of torque down low, there probably are a few HP to be had by installing the MTX cam.

 

[hawkeye18]

Over the past 10 years, it's been pretty well documented by the old-timers (perry?) that putting an MTX cam in an ATX will slightly hurt low end torque, but will increase high-end HP by quite a bit, while also making quite a bit more of the RPM band useable.

The ATX just stops making power after about 7000rpm, but with the MTX cams, that can be taken up to about 7500-7700rpm. Which is useful, since doing the 1-2 shift at 7500 takes the engine down to 3500 in second, which is where the engine really starts making power.

 

[thecrew2999]

because using the mtx cams in your heads backwards will give you 155+ hp