new member

[derner]

I've had my "X" for about a month now, and can't stop smiling! I've been a lifelong GM owner, and I just sold my '96 GMC 2500 Sub LT with a 454 for the "X". I'm extremely happy to this point. The hp of the PSD is good, torque is great compared to my gas big block. The mileage is awesome - I just pulled 15 mpg with winter-blend fuel with the cruise at 67 - a big change from 11 in my Sub! First thing after I got the "X" was get on this website - its a godsend to truck owners! After reading the muffler dilema, I decided to simply cut mine off and run straight pipe as an experiment. Huge difference in acceleration up to about 60 mph, with hardly any difference in cab noise unless you really get on it. I can't believe it doesn't sound like a stock car - its the best (and cheapest) mod to date. I'm looking at a Hypermax chip - looks like alot of WD fans out there, but I like the results of the dyno test of the Hypermax done last month on this site. Anybody running the Hypermax have any comments? Also, what's it cost for 550 springs and how much lift do you get? Can you run BFG 295's without some sort of lift? Thanks for any advice - I couldn't be happier!

[erlong]

Derner,

I have the Hypermax 330 chip now. The WD chip is going to a different vehicle. Definitely more power but I haven't been running it too hard because I don't have gauges yet. They'll tell you that you need gauges, and it's true. I've installed mine and am trying to baby my vehicle until the gauges arrive (any day now).

I noticed a power difference with the WD chip driving down the road. Didn't need to hammer down on the throttle nearly as much as I did when it was stock. The Hypermax is even COOLER. I noticed the power difference backing out of my driveway. The "go pedal" is a little more touchy now, but nothing you can't get used to. It's still not even close to being as touchy as a 5.0L Explorer...anyone with experience driving one of these will know what I mean--peppy little suckers.

If you're ever in the twin cities, just let me know, I would be more than happy to demo the toys I have installed.

Good luck deciding where to spend your hard-earned money! [img]images/icons/laugh.gif[/img]

[H ED S]

DERNER Welcome to the forum and the X brotherhood or crib [img]images/icons/crazy.gif[/img] . I think you will enjoy the forum as most of us do and you will learn a lot about the operation of your beast. Heck you haven't got but about a month before that ear to ear [img]images/icons/laugh.gif[/img] slips off your face. If you have not taken the bars off the luggage rack you might want to because they will wear your paint off. and do get some test strips and check the SCA in your collant. A few months back some came from the factory with none in the system. No big rush because it takes a good many miles to do irreversable damage.

Good luck and enjoy that bugger [img]images/icons/smile.gif[/img]

[Rattler]

Derner,

Welcome to the list. The fuel mileage is still making me grin also.

I must have been sleeping on this one but, can you explain the "cut off the muffler" deal for performance ??

Thanks,

Terry

[dandylee]

I must have also been sleeping! I'll second the motion for some clarification on the "muffler dilemna," and what solution the straight pipe accomplished.

By the way, I just took a 600+ highway trip with winter blend diesel, and got 16.5 mph going 65 or 70 mph most of the trip. Then, within the week I took a second trip of 350+ miles going 55 or 60 mph most of the way, and got 20.8 mpg. (manually figured. The trip computer stated a lower mpg. All stock equipment.)

So I'm happy w/mpg, too! By the way, I'm just approaching 3000 miles on the odo- and I'm thinking mpg should increase until the engine is broken in. Does anybody know how long it takes to break in the PSD engine? Any advice from you experienced beast-drivers would be appreciated -Dan

[derner]

Here's my logic behind cutting off the muffler: in reading all the posts on aftermarket mufflers (Flowmaster, Dynomax, etc), everyone says you have to order a 3.5" section of pipe to straighten out the path of the old setup because the factory muffler has offset inlet/outlet. Most retailers only sell in 10' sections, but you only need about 1.5'.

So I went to my local custom exhaust shop, and low and behold he and his dad are diesel owners (one with a Dodge Cummins and the dad with a CC Powerstroke) and they both run straight pipe on their trucks and said I should try it. They said I would hardly notice the difference in sound but I would instantly feel the power increase. I figured I would have to buy straight pipe anyway, so I gave it a shot. They were right - its awesome!

At regular idle, I don't notice a difference in the cab. Under normal driving (the one time I tried it) produced only a lower tone in the cab - not louder. Stepping on it you hear it slightly louder in cab, but again its more of a lower "growl", and the engine noise drowns out the exhaust anyway. On the outside of the cab, hardly a difference at idle. It is quite a bit louder when getting on it, and its really loud on cold days here in the midwest when the idle increases - then it does sound like a 747 sitting on the tarmac. But hey, I dig that!

Performance gains with no muffler - measured by seat of the pants - was extrodinary - especially from zero to 65 mph. The only other existing mod I have is a K&N. The other reason I started messing with the exhaust is I'm buying a Hypermax chip in the next month or so, and everyone says you need to examine the exhaust. Well, I looked at an aftermarket 4" kit, and the pipe was really light and "cheap" compared to the factory exhaust. In addition, Gale Banks said on this website that in testing PSD's, they noticed no increase in hp or torque going up from 3.5" pipe.

In the end, I think I can run a chip safely without the added cost of a 4 or 5" exhaust due to the fact I don't tow anything over 5000lbs and out here in the Dakotas we wouldn't know a mountain if it hit us. I'm not a penny-pincher, but when trading bucks for horsepower, I want the best return on my investment - and I think I have it. Geez, speaking of a penny-pincher, you just got my 2 cents and then some. Off the soapbox and on to something else!

[Rattler]

Derner,

Thanks for the explanation.

Terry