300 hp 4.0 sohc

so i bet one of my buddys the other day that i could get my 98 xlt 4.0 sohc to put out 300 hp without many crazy mods. im kinda doubting myself considering its probably lost some ponies over the years but i thought it be interesting to see if it can be done without a turbo or supercharger. im gunna do some of the basics, intake, exhaust, throttle body, and all the other little things. i already have flowmaster super 44's and a kkm intake but im thinking about swapping them out for a k&n and other mufflers, im wondering what muffler and cats would be best. im also changing my gears to 4:10s but im not sure if that actually adds hp. any other ideas im thinking about putting some jba headers on but ive heard they dont do much for the 4.0s.

 

[joecrna]

300 hp normally aspirated, at the fly wheel, yes. It'll take some doing though. Cold air intake and free flowing filter. Lightening MAF, Mustang 4.6 3V throttle body rolled and blended. Headers, if you have to pass smog they'll be shorty replacement headers (JBA or Gibson). Mandrel bent exhaust tubing all the way back. Got to leave the stock Cats (emissions certification again). A set or a single free flowing muffler depending on your exhaust design.

Now it gets tricky. The heads need some work. Super Six offers a stage III head with larger valves, polished and ported. Hotter cams are necesary at this point. There are only one or two choices. All reduced radius designs. Maybe a custom cam by one of the big manufactureres if money is not much of an issue. Custom forged pistons to bump the compression ratio a point of so. Custom H beam rods and get the crank polished and shot penned. We want this engine to last.

Now you need a good custom tune done a dyno running the exact same gas you will usually use. Once you've done all that, you will essentially have my engine. Its not complete yet but I only expect 285-300 hp. If you want big power, put on a turbo or supercharger. Run whatever amount of boost you need to get the HP you want and race gas if you're looking for more than about 450 hp. A big ole shot of nitrous would be a lot easier/cheaper.

Or you could just get a bigger engine. Im not, but I probably should.

 

[Sams01XplrSprt]

do u got pics of ur explorer

 

[2000StreetRod]

225 rwhp goal

My goal is 225 rwhp with no modifications to the engine internals and normally aspirated. I think that is quite a challenge and I'll be extremely pleased if I achieve it. My stock power was 150 rwhp and I'm guessing its now approaching 190. That's a long way from 300! You'll find that its much easier and less expensive to add 50 hp to 150 than to add 50 hp to 250. Plan on spending $5,000 or more to get to 300 rwhp and having the engine stay together.

 

[tgreene92]

yea im not looking to spend 5 grand, i think 225 is a more obtainable goal thatll save me stress and money, let me know some of the things your doing and maybe how much it is costing you to obtain 225. i havent had my car dynod yet but id have to imagine its still putting out more than 150 considering it was supposed to put out 205 brand new. do you have a sohc or ohv engine.

 

[2000StreetRod]

hp vs rwhp

205 hp was the advertised rated engine power not the power at the rear wheels which is typically 20% less. I have the SOHC with 150,000 miles at the time I first put it on the dyno. Check out the links in my signature for what I've done so far.

 

[joecrna]

That 300 hp is costing me near $15k. I want it to be very durable. It could probably be done for $10k if you skipped stainless exhaust, high tech coatings and the like. Still, its not cheap. And yes, getting the first 50 horses isn"t too bad. After that it gets hard. I am using pro builders too. Sadly I no longer have time to do such extensive work myself. Some of the original brain work was done by Saleen before the buyout.

 

[techieman33]

Look at this thread, he did pretty much every bolt on you could do.
http://www.explorerforum.com/forums/showthread.php?t=162692

 

[turbo cat]

Not going to happen. just go fi it will save you alot of money

 

[Iven]

My Explorer is just as I got it. Did install a K&N air filter. 4.0 needs all the help it can get. But as we all know Money is tight. Would duel exhaust help that much? I know if it breaths , it might help. Any help we can get will have our thanks. Iven

 

[htrdlncn]

It still amazes me all the time and effort people put into
hp "numbers" yet never actually run at a track..
Be suprised how many "dyno queens" get their ass blown off at the track.
A lot of the stuff the looks good on a dyno doesnt always work well on the track.
All the hp in the world will do you no good if you dont get to that finish line first.

Like my sig states, The BS stops when the green light drops.
All the pretty dyno sheets in the world wont help if your looking at someones elses tailights at the end..

 

[techieman33]

It still amazes me all the time and effort people put into
hp "numbers" yet never actually run at a track..
Be suprised how many "dyno queens" get their ass blown off at the track.
A lot of the stuff the looks good on a dyno doesnt always work well on the track.
All the hp in the world will do you no good if you dont get to that finish line first.

Like my sig states, The BS stops when the green light drops.
All the pretty dyno sheets in the world wont help if your looking at someones elses tailights at the end..

I totally agree with you on that.

 

[Elessar65]

Horsepower sounds nice, but its your power to weight ratio that make the biggest difference. That and a good suspension set up. Check out a Caterham sometime. Or the Ariel Atom. The Atom will make a Z06 look like a pinto around a track.

 

[patman]

subscribing

 

[jah81592]

My whole reason for posting track #'s instead of dyno #'s all those years. I feel they are the most important. As far as seeing 300 to the wheels, N/A, you won't unless you jug it. Technically the engine will be n/a and you could win the bet with your buddy.

 

[Elessar65]

Have your truck lose some weight. Its different for every vehicle, but the general rule of thumb is that for every 100lbs you shed, you will be 1/10 of a second quicker. Also, reduce your un-sprung weight. ie the stuff at the end of your axles: wheels, tires, brakes. That will considerably improve acceleration, braking, and handling.

If you want 300 N/A horses, swap in a stroker V8, like a 347. Otherwise you'll be on the bottle.

 

[techieman33]

You could do 300whp on a 302 n/a pretty easily wouldn't need a 347, that would be closer to 400whp if built with good parts.

 

[patman]

i think theres a requirement in the bet that it has to be the 4.0 SOHC

 

[Elessar65]

you could start with the 4.0sohc, and stroke and bore it.

 

[techieman33]

you could start with the 4.0sohc, and stroke and bore it.

There really isn't a whole lot of room for either, but I believe Jakee is working on stroking it a bit.