Hello I am new today just found your site. I am wondering if anybody else out there is putting performance mod on their vans. I have a 1990 e150 conversion with a 5.0. In the past few years I have added a set of shorty pacesetter headers, a throttle body spacer and modified the air intake box and install a K&M filter. These mods gave me noticeable towing power to the rear wheels and better gas mileage. I sold my camper and am now going to go for better gas mileage. I have purchased a set of 2:73 gears for the rear end, current have 3:08's. I am going to install a cam that gives me peak torque around 2500 rpm. I would like to get rid to the cat and install a H or X pipe and open up the exhaust. I cannot find anybody that make a cross over pipe for a truck this old. I was wondering if anybody has tried one that would fit a 5.0 Mustang?

 

Since I have 0 mods - I can't help you much with with the crossover pipe, but I would recommend some caution with the gear ratio. There is such thing as going overboard. If you get the cruising RPMs too low, you wind lugging the engine and putting more strain on the transmission. When the tranny has to hunt up and down, it hurts your gas mileage. You also need to consider where you drive the vehicle. Around town, the 2.73s are likely to hurt your mileage because you'll have less mechanical advantage in getting the van's mass moving. There may also be some loss at speed due to the lack of aerodynamics on the van.

Of course, this is theoretical - I'm sure that someone will chime in with some real world experience with a 2.73 gear set in an Econoline.

 

I only put 3500 miles a year on my van all highway. I agree if I drove in the city more my mileage could suffer. My goal is to lower my rpm at 70 mph. Before the mods I made my van could not hold 70 mph in overdrive with a 1000 lb camper on the back with the cruse control on. Now it is not a problem. As far as the strain on the tranny I don not know for sure but my guess it should not be a problem.

 

Buddy, if you put those gears in you're gonna hate it in the city, it will be gutless, the 5.0 is wimpy as is in these heavy vans, now you are looking to kill it. Depending on the current exhaust size, you will lose the low end torque, the cross over pipe will deepen the loss. You best live in a flat state, because you'll not be able to retain over drive on the highway, every little incline will have it searching for gears, you're not supposed to tow in overdrive either, you're gonna find out how expensive rebuilding those transmissions is. I'd not tow with any gears lower than 3:50's, and never in overdrive, you're looking to make it impossible to tow at all.

 

my experence with two of these vans. i went from a 3.42 gear that would lug at 70 loaded. to a 3.73 both gerar got 15 mpg towing aceretaion improved . underdrive pulleys noticable improvment. repalacing engine van with dual electrics improvement hand made 4" cold air intake. improvment timing 12degrees be carefull inthe mountains noticable. raised fuel pressure noticable. 160 degree thermostate notisable. free flow cat back system minor power change but sounds good f150 processor. van transformed from a pidg to being able to get out of its own way. still gets 15mpg .

 

Ajax, what van do you have, I'd like to see your intake, I knocked the silencer out of mine and put in a K&N, but would like something different, to get more air, the end elbow before the filter is limiting now.

 

Pics Please !!

 

I am not planning to tow anymore. I just want the mpg. Right now I only get 13 mpg at 70 mph with a 3:07. If you are getting 15mpg with 3:73 in it must be down hill with a tail wind.

 

Like I said, better live in a flat state, those gears will have your transmission searching on every little incline, won't matter if you're towing or not, the only time those gears worked was in the older 3 speed transmissions, before overdrive. You say a cam with peak torque at 2500 RPM, you do know you just moved the power band on the engine higher than stock, counter productive for what you're doing,

 

Just a few mods I have done on my E350

Dual exhaust sportside, K&N Cold Air Intake,Jet Power-Flow Mass Air Sensor,DiabloSport Predator.
Hellwig Load Pro 25 Heavy Duty Helper Spring on rear.Rough Country Steering Stabilizer.
LT265/75 R16 Firestone Destination M/T on stock wheels.

 

I have owned 4 big vans over the years. In the mileage scramble days, I got a GMC 2500 van with a 305 in it--admittedly a dog of an engine, but a somewhat lighter van than yours as well.

Stock gear ratio was a 2.73 with a 3-speed Turbo 350 trans, and a lockup torque converter. With very light loads, it could not make it up a very gradual uphill without going into 2nd gear.

I put an Auburn posi in the rear axle and changed the axle ratio to 3.42. It completely changed the vans' character and I did NOT lose gas mileage in either the city or the road. And the trans was not an O/D transmission. But mileage was 12-13.5 with either gear; it was a carbureted 305 and just not a great mpg combo.

I currently have a 4.6 in my 2002 E150, stock 3.55 rear end (Eaton posi added by me) with the O/D transmisison. Works great. Amazing mileage--it can break 18 mpg on freeway runs if I keep it under 70 mph, which I usually can't. Still gets over 17 mpg at about 75 mph.

If you have an O/D transmission, you absolutely should not go to a 2.73. It will spend its life struggling on uphills. With a short stroke motor like a 302, stay with what you have. Oh yeah, my first van was a 1973 Ford flatnose turtle top camper conversion with a 302 and a 3.25 rear axle. It got 12-13 mpg...

I also bought a new Ford F100 pickup back in 1978 with a 300 inch six, 2.75 rear axle, AND the 4 speed O/D manual transmission. It got decent mileage but could barely hold 55-60 mph on the slightest of uphills. I would have preferred that truck with a 3.25 axle. It would get 22 mpg unloaded, at 60 mph (these were the days of the national 55 mph speed limit). At faster speeds, it would still usually be over 20 mpg.

George

 

I agree that the 5.0 does not belong in E-van. The 180hp from the factory is not enough. Before I made any mods to my van I could not run at 70 pulling a small camper. For a two years drove from Indiana to Florida in third gear and averaged 8.8 mpg. I added about 15 horse power and could now drive in overdrive with no problems and average 12.5 mpg. Yes I still have to take it out of overdrive in the mountains. I would like to add another twenty hp with a different cam. This is supposed to work well with the shorty headers I already have in place. I believe that I am running about 2800 rpm at 70 mph with my current set up. I just installed a tac this weekend but have not had time time to try it out yet. I would like to get my rpms down to 2500 at 70 mph. Yes the 2:73 may be too much but a got a set off of ebay for $30.The Mustang guys sell them cheep. I can always take them out if I don't like them. As far as the van being a dog in the city it already is now so I am used to it.

John

 

Didn't you say you have an overdrive transmission? I don't think your rpm calculations are correct; I remember my F100 with 2.75 axle and a .8 or .79 overdrive gear (final drive ~2.19) keeping the engine at about 1600 rpms at 60 mph. A quick calculation gets me 2215 rpm with a 29" tire and a 2.73 gear and NO overdrive at 70 mph, so the OD will push you down to about 1700 rpms. Looks like an Epic Fail to me. Go get a rear wheel horsepower/torque reading on a dyno at 1700 rpms. It'll be a little better than a lawnmower with a 302 with a cam in it.

Just because you got a good deal on the gears doesn't mean they are gonna work, but put 'em in and report back if you want to go through the drill. I say that they'll accomplish worse than nothing.

A big van with 2.73 axle and a 302 just does not compute, even if you had no overdrive. I've had vans and trucks with long gearing, and I really believe that there is no way your project will not work the way you want it to. A hotter cam and shorty headers will just push the torque peak up and move you further from a useable vehicle. My old 300 inch six with 1 barrel carb had its torque peak at 1600-1800 rpm, so it would do *something* cruising in that rpm range. Your 302, not so much.

George

 

Very few understand upgrading a cam, just the word performance is all they read into it, don't know how to read the numbers. BTW gearing is an expensive venture, to have it done right we're talking new seals and bearings, then there is the labor, it comes out around $1000, that's a lot to spend for something that is a mistake.

 

$1000? Labor? Who pays for Labor! OK explain this, my 3.8 Buick Park runs 2000 rpms at 75 mph at gets 25 mpg. My Mercury Villager with a 3.0 runs 2800 rpm at 75 mph and gets 22 mph. I just have to get usable torque to the back wheels.