K&N FIPK Intake and Flowmaster exhaust

[JoshC]

Last week i bought a K&N FIPK intake 57-2541 for my wife's 01 5.4. Installed and test drove it and wow, what a seat of the pants difference. This is with stock exhaust by the way. Wife complained about it getting bad mileage around town now. After consulting with a few of you on here, we decided it's all good I drove the truck around a little bit today and it was getting great mileage on highways and interstates, but pretty poor mileage in town---stop and go. On the highway doing only 45, level ground and just enough fuel to maintain my speed i reset my MPG gauge and it put out just over 22 MPG. On the interstate doing about 65, level, enough fuel it was going about 18-19. Not to bad, i was very pleased. But around town was another story, it wanted to get to around 10-11 then, worse then it was on the same drive when it was stock. All in all, i love it and would recommend to others!

I ordered a Flowmaster 50 Series Delta muffler, single in single out from my local shop, again after getting opinions from here. It came in today so i went over to have it installed. The guy at the muffler shopped talked me into upgrading to a 3" mandrel bent tail pipe for the same price as 2.5". Not sure why he wanted me to go with that, but for the same price why not. We decided that since i didn't go with a cat back system that i wouldn't loose any back pressure because between my cats and muffler i had 4 bends, plus all the work to get the exhaust over the axle. Got it all welded it up and fired her up and boy did it sound good. It isn't overwelming, even with the windows down, but sounds great running through town. Even when you get on it, it's not to loud at all, but with the sound of the new intake and the new exhaust, it sounds good.

As for the performance notice and mileage difference after adding the exhaust i wasn't please. I couldn't tell any difference in power, actually feels like i did loose some torque. The mileage also fell on it's face, wasn't please with that at all! In all reality, i just counter acted my intake productivity with the exhaust. I can't really explain that one?? It sounds good and the 3" pipe coming out the side looks good, but i don't like the outcome.

Hope this helps someone that's thinking about going the same route

 

[ELVATO]

I think it's said that exhaust upgrades kinnda hurt your low end power. The gains are found as you rev up the car. So maybe, you have to get on the gas a little more to get more of the "low" end work done, like stop and go.

Maybe I'm wrong. Don't know.

 

[AvroAero]

Thanks for the info, I'm in the process of doing pretty much the same thing with my 99. I've ordered a K&N intake and am gona have an exhaust custom built for my truck with headers.

I know a guy that has a 5.4L 99-02 generation that put headers and a catback on it and he said he got 310 horse out of it with a chip i think. which is like a 50hp gain im pretty sure. Thats a lot. If I could get my 4.6L to 300 or so hp with the exhaust and intake I'd be happy.

 

[JoshC]

I got to drive the truck a bit more today. I love the sound!!!!! Windows down cruizin it sounds great. The power isn't to bad low end, i can punch it for a second and chirp the tires, but i haven't tired to spin them really.

 

[green03]

You may need a custom tune to add some timing in in the lower ranges to negate the backpressure changes. I know i got every bit of my low end and mileage back with tuning. That's why i recommend that you leave the stock pipe diameter if you don't do any tuning to compensate for the lower backpressure at idle.

Matt R

 

[JoshC]

Just an update. Not much change. Mileage is still where it was at stock. Only difference now is that when you get on it, it takes more fuel

 

[AvroAero]

I just put my intake on my 99 4.6L expy and its pretty good. It went in a little slower than I thought, instruction's pictures were hard to make out sometimes. That and it's not VERY cold air, it doesn't sit right against the wall of the engine compartment so hot air can reach the filter. Mind you it looks nice and sounds pretty nice to. Much lowder than stock when it gets up to 3000rpms going down the road. Not much dif with the windows up but with them down it echos in the cab. A fair boost in power for what it is, feels like accel from 40-100 is quite a bit quicker. IMHO not worth the 400 CAD it cost me. Mabye 200 in materials, another 50 or more for the K&N brand would be more reasonable. Looks nice in the engine bay. To early for millage improvement but I doubt it, considering I'm on it more now .

 

[ELVATO]

Hehe, yes, the sound of a CAI is awesome

Mine cost less than 200 (if I remember correctly) to buy and install

 

[AvroAero]

Yea, I think it may of cost less if I ordered it from the states but I gave the business to the local guy and it came out to more than I thought it would. Live and learn.

 

[AvroAero]

I gave it a test today as I was doing all highway driving. I recorded 171.4 km travelled on about (maybe less) 25 litres of fuel. When I figured it out I got about 14L/100km which is about 2 litres better than I guesstimated I was getting before. Most of the travelling was 90km/h to 100km/h.

I think it may of improved it, and 14L/100k is pretty good for a fullsize SUV. BTW mines mounted on a 1999 4.6L.