I bought my '00 F-350 CS last summer, V10 Auto 3.73 gears, 265/75's. I just towed my enclosed snowmobile trailer for the first time last weekend. I want my 460 back.. It kept shifting up and down and to keep at 60 mph up the mountain I was at almost 4000 rpm. The trailer is 3000# with about 1500# in toys. Not much for this truck. I pull some steep grades but they are the same ones that I have pulled for years with other trucks. I even pulled this same trailer with a '90 460 and it did about the same for $15k less. The 460 would keep an even at 60 mph even in 4wd and I had clear roads this trip.

The only mods I have done is the exhaust and a K&N filter. I had a custom y pipe built into a Flowmaster 40 (single in dual out) then out dual both sides. It sounds great but it's like I lost all the torque unless I rev it like a small block V8.

Other than towing the big hills the truck runs fine. I Drive it every day with no load and it runs great. Did the y pipe kill my torque or is there something wrong?

 

Welcome to FTE

I think that your biggest problem is the 3.73 gears.

Denny

 

I think it's a part of it, but not all of it. I have a pre-PI engine with 3.73 gears, with my 245/75/16 tires I had no problem pulling and extra 2 or 3K pounds around over the weight of what you're towing. The Y pipe may be another small factor but I still can't see it effecting performance that negatively. Now if there was another hp robber or two, the combination of them may be enough.

I've told this story before, but it bears repeating; My bro-in-law owns an electrical contracting business. He previously always ran F-series, V10 pick-ups. He's gotten a little smarter recently and bot a couple E350 V10 vans, but that's neither here nor there.

Since I'm a highly paid negotiator, who also spent some time in the car business I buy all his trucks for him. And I gotta say, we bot a 2001 F-250 SC 4X4 that was a DOG. His 99 F350 CC 4X4 would flat bury it in a race, and my 98 E350 V10 would embarass that 99 F350. He didn't care, since he had his crews drive the 2001, but he did see this truck did NOT have it going on. I told him it would be a quick fix at the dealer, that it probably just needed a re-flash, but he didn't care. He never drove it.

This phenomonan was more around a bit more a few years ago, the difference in two identical V10's. I would certainly be suspecting something, as it's not normal. That small load should not effect that V10 nearly that much, Ken

 

I have a 99 Crew cab with 3 series gears, and my buddy has a 00 extra cab that has the 4 series gears in it. My truck will flat out eat his alive. Always has from stock, right on up the line of mods we have both done. I have a 50 series flowmaster, he has a 40 series. The 40 is louder that mine, but mine pulls much harder than his truck. To this day, we still are at a loss, technically speaking his truck should walk all over mine, but it doesn't

 

Fuel filter?

 

Fuel filter ,fuel pressure ,fuel pump in that order!
373 gear will cause a slight problem.
Rich

 

When looking at the torque generated by a V10 you must consider at what RRM the engine is at peak torque. The 2006 brochure says the V10 delivers 457 lb-ft at 3250 RPM. The 96 F250 I drive with the 460 has 400 ft lb of torque but at only 2200 RPM. It is a significant difference in the two engines. This is is why you are not seeing the performance from the V10 as compared to the 460! From what I am reading on this forum all the guys are saying change the differential to 4.30 ratio. This is why they are saying it. The V10 has to spool up to deliver its peak torque and 3.73 gears are keeping it below peak. If you change ratios then the V10 will perform but you will have to get used to the higher RPM. I think this is why my 460 gets nearly the same mileage when I'm towing or non towing. I have only seen a range of 2 or 3 mpg difference in the two. They are saying on this forum that a V10 gets 14 mpg or better and I don't doubt it one bit. However when you hook up a load and pull hard the V10 is going to have to reach it's peak torque RPM or she will be a dog. Granted when geared right it will be a mule but 3.73's are for gas mileage not pulling. Who buys a super duty for mileage?

I'm in the research and thinking process about my next truck. I want the V10 and have always had Ford trucks. It is interesting to see what everyone says about the V10 on this forum. I was leaning toward the Cummins in a Dodge until I started reading about the good things said about Ford's v10. However I am still haunted by torque figures and RPM. A good work engine can move the load at lower rpm's. The Cummins peak torque is at 1600 RPM!!! Can anyone correct my thinking! I'm still leaning toward the V10.

 

Alright, try this one on for size, the 3V V10 makes 94% of its torque at 1950 rpms which is more torque than that ol 460 ever had. Also it makes over 80% at 1000 rpms.

My dad still has a 460 that he of course swears by it but let me tell you his is geared down to the point that when he is in OD at 70 mph the truck is running more rpms than mine in 3rd at 70. I beleive 70 in 3rd for me is around 2600-2800 rpms, that 460 is pulling around 3200 rpms at 70 in 4th (OD). You have to wind the 460 up no different than the V10. Many of course don't know this because many of those trucks never had a tack in them. Heck we had to put a tack in his, and at first we thought it was way off, but after further invetigation we found it to just be running that high in the rpm band. and JFYI he has 4.10 rear gears in a 96 dually. Mine has 3.73s but even if I went to 4.30s I still be just about 1000 rpms lower in the same gear. This tells me ford had some deep trany gears back in those days!!


I do have to agree with everybody but the V10 should have no probelm towing 5-6000lbs. Heck I tow over 10k with mine (20 valve with 3.73s) and I just drop it in 3rd and let here buck. There are two hills that I have to find 2nd to hold speed but 4000 rpms for 30 sec is nothing. My wife thinks I'm demented because I actually look forward to towing the larger hills we come acrross, I take great pride in passing people going up the hills with 10k in tow (4 lane road of course), it even makes it better when its a smoker or another brand, lol.

Also I have no problem getting 13-14mpg on the hwy. I've seen 15.6 one time but I wont call it my average since it took me driving like an old woman and keeping my speed under 70 and a 15mph tail wind. 11-12 around town and about 8-9 towing depending what I'm try to pass on those hills, lol.

 

Thanks for all the replies. I sounds like my problem may be a combination. My exhaust has probably raised the already high torque range. I sounds like it is higher than I expected and it is different than my old 460. My 3.73 gears add even more to the problem. (I wanted 4.10's but all the trucks I found had the 3.73's)

What I am hearing is that even with all this I should be able to keep 60 mph up the hill with a 4500# trailer. I couldn't do that. Even kicking into second I could barely keep up and pedal to the floor it would not stay in second more than 5 seconds. I didn't like manually having to keep it in second gear at that speed.

Maybe I have something else wrong like maybe a fuel problem. I have not had any luck with the dealers I have been too dealing with performance problems. They just tell me it is within speck and take my money. Is there a way I can check some of these things or does it take a full scope and expensive tools?
Maybe if someone had a spare stock Y pipe laying around I could get some torque back.

Rod

 

Wouldn't the truck stumble or flat out stall from fuel starvation if one or any of these 3 these things were bad? I changed my fuel filter out just because I thought it might part of my lack of power issue, made no difference. Fuel pressure check indicated 36 psi. That is right in the middle of the specs. it's suppose to have. Mine still flat out dies uphill with less than 5000 lbs. behind. Stock exhaust cept for a Bullet muffler, Airaid intake and TB spacer, and SCMT 1715 on tow mode.

 

Hey SLE, my 460 with a 4.10 is turning 2200 at 70 mph in OD. If I kick it out of OD it goes to 3200. Just checked it on the Interstate after I read your post today. Could they gear the tranny's differently for the V10? How do you find out the technical data on stuff like this? I would love to see a power graph on the V10.

 

I too vote that my V10 with 3.73 starts to really get winded when pulling up hill with a 4000# load. I shouldn't have to throw a rod just to get up a hill.

 

Although the trailer & gear may weigh the same, I bet the weight of the old & new trucks are substantially different. Wouldn't suprise me if the Super Duty weighs a full 1,000 lbs more than a '90 model F250. This will contribute to some of the differences you're feeling.

You bought a used truck- you may or may not know what the previous owner did (or didn't do) to it. As mentioned before, sometimes engines just aren't as good as they should be. It could be that this is one of those "dogs", but I'd go through the truck and perform all of the usual maintenance (plugs, filters & all fluids)- regardless of the number of miles on the odometer.

 

You're all in denial guys. I mean, I think it's obvious...he's driving a V10...

 

Clean the mass air sensor, it is common for the oil in the KN filter to foul the wires in the sensor.Try an inj flush if it has never been done.Use good gas,inferior gas will cause detonation, which the pcm senses thru the knock sensor and retards timing which will kill some power. Is the trans in top shape? Driving technique? [not saying yours is bad.] A lot of factors are involved in pulling good. Your exhaust is not the problem.