Power Impressions of 5.0 5sp Vs. 4.6L 5sp

[sgramer]

I have both a 91 GT 5.0 5sp, and a 2002 4.6l 5sp. My question is, why does the 91 seem faster. I can understand in everyday driving, around town, the 91 seeming faster, well it may actually be. The power curve in the 91 is more conducive to low RPM driving, I.E. 300 TQ @ 3000 225 HP @ 4000. While the 2002 has 302 TQ @ 4250, and 260 HP. The interesting part is, even at high throttle settings, not WOT, the 91 seems faster, or the 2002 is not much faster. To really notice a difference, I need to beat the daylights out of the 2002. If I drive one then the other, and floor them both, I am talking about driving abusively, the 2002 seems marginally faster. Do any of you own both a 5.0, and a 4.6, have you experience this? I would think the 2002 would seem faster flat out. Both the 0-60 times and the quarter mile times are better. Why is this?

I understand the push rod vs. the overhead cam, power curve issues. Every time I drive both in the same day I wonder, which car is faster. They are worlds apart in the feel when you drive them, but in sprints to eight, when you get down to it, they feel the same. One does not feel like it pulls harder than the other over all, or does it seem one get there faster. It just is baffling that the extra horse does not show, in more of a major way.

Any input, or experiences would be appreciated.

Scott

 

[Screwed2V]

What is the weight of both cars?

 

[2002BLGT]

I used to have a bone stock 87 LX that ran low low 13s with the stock mufflers on it , It was ordered with no air , roll up windows , cheap 4 cylinder interior , 5spd with optional 3.08 ring gear , no radio , so trust me I know the feeling , that car pulled like a motha , but when I got my 02 GT I could tell it didnt have the mustard down in the lower RPMs , I have found the quickest way to give it some kick down low is to splurge for the long tube headers , I guess its the heads and the way they flow , they really respond well to them , better so than the older 5.0s by a mile. Get you some of those put on and you will start to feel the torque kick in a lot earlier in the powerband .

 

[2k2SilverBullet]

the other reason why is that 5.0 got greater down low tq

 

[lopey4.6]

The 5.0 may seem like it will pull harder out of the gate but when you get above say 4500 it falls flat on it's fave where the sohc motor pulls strong to redline.

 

[NasaGT]

I've got a bone stock 87 LX that is like 2002blgt's - no power anything, but with radio + AC. It pulls like no tomorrow, but I've never had it at the track to know how quick it is. When I first got my 02 GT, it seemed like the 87 felt faster, but It was really just a matter of learning to drive the 02. Like you said sgramer, their powerbands are different. I think the stock 5.0 gives you the feeling of acceleration at the low rpms (where all the torque is) and kind of fades as the rpms climb, whereas the mod motor gives a smaller feeling of acceleration across the entire power band since the peak is near the top. Its one of those area-under-the-curve things, the mod motor is quicker than the 5.0, but the 5.0 gives a bigger punch when you first get on it. Just my two cents...

Hopefully this spring I'm going to get both of these cars to the track and see how they do.

 

[Beau]

i used to have an LX 5.0..and it felt very strong. when i bought my GT new in fall 2002, it felt different. the GT seems to pull stronger higher up but the LX accelerated faster from a stop IMO..

 

[cap42]

I had a 83 lx 5.0 and I had to practice and learn how to drive my 99 cause they are 2 totally different beasts. The old Fox bodies were generally lighter by a few hundred pounds plus they made their torque down low which gives a much different sotp feel.

When I first raced my 83 at the track the best I could ever pull was a 14.7 I never got to run it at the track after I made a few mods to it but I would figure I would have been low 14's. So far the best I was able to do in my 99 was 14.2 and that was when it was bone stock. Come spring I'll see what difference's my mods have made and if I can break her into the high 13's.

 

[KISSEL]

Same torque roughly 300-302, but 5.0 comes on lower in the
rpm range (roughly 1200 rpms difference). I think that it would be safe to say that the 5.0 is better at stoplight to stoplight driving, but the 4.6 will take it in the quarter (stock vs stock). 2 different animals here. I used to own a '92 gt (auto) and now I have a 4.10'd 5 spd '01. Even with the 5 speed and 4.10, my old auto still had more grunt down low, but it was a dog on the highway. The ohc 4.6's love highway, but unfortunately I'm more of a stoplight to stoplight kind of guy. They are different engines that are both amazing in their own ways.

 

[sgramer]

Hey, thanks, I guess I am not crazy. Both cars are loaded, the 02 is a premium, and the 91 has everthing even a sunroof. I am not sure of weight of either car, but they both are heavy.

I guess I just expected to feel a night, and day difference from the 02, because of the extra power. In the world of everyday driving though, I don't and will not, and the 91 even has 2.73s.

I hope to get them both to a track, and I will find out. I am sure the 02 will beat the 91 with no problem.

Thanks,
Scott

 

[KISSEL]

Again, it also has to do with the powerbands, horsepower and torque.
For example, I drive a 5.4l f-250 work vehicle and the torque right off the line
(330 ft/lbs crank) feels greater than the 5.0 motor,but the bigger engine (5.4) is
rated at something like 225 horsepower and that's where you notice the difference.
It kind of falls flat after 40 mph or so. Same theory with the 4.6/ 5.0. If you take the ratings (225 and 260 respectively), the extra 35 horses are felt more at mid to top end, rather than down low. When comparing torque and horsepower, I like to think of
it as torque gets you moving and the horsepower is more of a top end unit of measurement.

 

[sgramer]

ya, the power band on the 5.0 is more biased tword the lower RPM range. Glad to see I am not the only one that has notice this, I guess I am not insane. Thanks, for all the observations.

Scott

 

[hognutz]

I have had 4 5.0's try to race me since I bought my 4.6 and I have beaten them all easily. so I don't see how a 5.0 could be any faster than a 4.6 stock. my 01 felt slow to me when I first purchased it. I had an 88 iroc before this car. my iroc felt faster. when I race irocs now I rape them. So it probably just in your head.

 

[sgramer]

Funny, I sold a 89 IROC L98, along with my 94 GT when i got my 02.

Scott

 

[VOORHEES]

Coming from a 94 GT, I understand that grunt from a 302 has down low in the rpm's. But make no mistake the 99 GT will scorch at the higher end revs.
-Jason

 

[jfranci3]

Another reason for the difference is that the 2002 GT engine has to operate over a broader power band. This means all the intake part sizes are larger, which will remove some of the responsiveness. To illustrate this - Try comparing a GT to a Mach1, you'll notice the GT is much more responsive.
Try opening the 2002 just to 3/4 throttle. you'll get a better response than just flooring it.

 

[mogs01gt]

I have both a 91 GT 5.0 5sp, and a 2002 4.6l 5sp. My question is, why does the 91 seem faster. I can understand in everyday driving, around town, the 91 seeming faster, well it may actually be. The power curve in the 91 is more conducive to low RPM driving, I.E. 300 TQ @ 3000 225 HP @ 4000. While the 2002 has 302 TQ @ 4250, and 260 HP. The interesting part is, even at high throttle settings, not WOT, the 91 seems faster, or the 2002 is not much faster. To really notice a difference, I need to beat the daylights out of the 2002. If I drive one then the other, and floor them both, I am talking about driving abusively, the 2002 seems marginally faster. Do any of you own both a 5.0, and a 4.6, have you experience this? I would think the 2002 would seem faster flat out. Both the 0-60 times and the quarter mile times are better. Why is this?

I understand the push rod vs. the overhead cam, power curve issues. Every time I drive both in the same day I wonder, which car is faster. They are worlds apart in the feel when you drive them, but in sprints to eight, when you get down to it, they feel the same. One does not feel like it pulls harder than the other over all, or does it seem one get there faster. It just is baffling that the extra horse does not show, in more of a major way.

Any input, or experiences would be appreciated.

Scott

well you have to remember that the new car is more refined so the feel is going to be more smooth and less "rough". Not to mention the power curve, that low end torque that comes on quicker only helps to the 1/8 mile, maybe. When you have torque that goes higher in your power band, the car is going to pull a little harder after the first low end torque eachs its max torque. Its hard to explain but the 02 should pull harder when running them through the gears. I have raced a lot of minor bolt on 5.0s and they always take me in first by about a fender. After I slap second its all over. I walk em bad.

The low end torque of the 5.0 is going to make it feel faster but it really isnt.

 

[Sam98]

The Fox body is lighter than the newer Mustangs. I sold my 88 5.0 to buy my 98 and the 88 was noticeably faster than either a stock 98 or a 95 Cobra I test drove with the 235HP 5.0L. The Fox body is almost as flimsy as a Yugo, but they are light and fast...

 

[ttown]

I've beat the 3 5.0's I've raced in my 02 GT. The thing is with my 87 GT it felt weaker stock and I was disappointed until I did all the free mods which one of them being jacking up the timing 5 degrees. The the torque was unbelievable.

So when your talking 5.0 vs 4.6 I don't think I know of any that haven't had the timing setup. Put a T/A on your 02 and set the timing up and then compare or get a dyno tune and compare.

Of course most that would consider free mods with the 5.0 as stock wouldn't consider the 02 stock doing the same tricks since you have to buy stuff...........

 

[sgramer]

The 5.0 is still at 10*. I am going to get the preditor when it comes out, I will use that to mess with the timing.

Try opening the 2002 just to 3/4 throttle. you'll get a better response than just flooring it.

You are right on that one, they both feeal more responsive at 3/4 throttle. Then just ease in as the rpm climbs, and the air velocity gets up.

Scott