custm2500

iTrader: (10)

What you don't understand is that hp is held back from the factory. The Stock exhaust, stock intake, and stock tune, all restric hp. The HP spent to push the exhaust out the tail pipe, the HP spent to suck air through the stock air box/filter can be spent moving the vehical down the road.

Also a tune advances timing and this requires no more fuel. You can make ALLOT more hp from advancing the timing allone.

Also making more HP then stock often results in better fuel ecconemy as long as you use that HP efficiantly and not shoot your best 0-60 every red light.

Again I don't want to debate this any further but do a little bit of research and you will see you original statement and this rebutle has little to no fact in it. As I make changes we will see how much the known factors help and what if anything outside of the box can do.

06murder

sounds like u been buzy there buddy with 5 kids...

1989k1500

iTrader: (23)

Yea I would disagree with pretty much all of that.

custm2500

iTrader: (10)

If I were using my toung I wouldn't have as many kids. 3 are mine and 2 are my girlfriends. I get mine atleast once a week over night and fri-sun every week. We certainly have a busy household most days.

1Bear

iTrader: (1)

I know you have what you have to work with, too bad it wasn’t at least a ’98 with a L29 where you could have it tuned a little easier, beings there are not too many people in the chip burning business anymore and even that depends on whether they have a prom available. No, the old big-block trucks won’t get stellar fuel mileage by any definition, but they can be improved upon just the same. We had a ’97 crew-cab dually with the L29, 4L80e and 4.10’s, in which it got comparable mileage as to what everyone sees, it would get 10mpg no matter what, uphill/downhill/loaded/unloaded. After tuning it would get 14mpg on the highway, still nothing to write home about, but 4mpg is a hell of a difference, especially when the mileage is so dismal to start with. Besides tuning, which made the most dramatic impact, a good tune up, re-working the exhaust to something a little more free flowing (not to mention sounding better) and a new set of Michelin tires on aluminum Alcoa wheels and a good alignment to reduce all the rolling resistance I could seemed to work. Was it worth the investment, I don’t know, but it sure was nice being able to pass a few more stations before having to fill the Tank up.

Even though the TBI trucks are if nothing else reliable, one area on the older trucks to keep an eye on is the ignition system. The TBI trucks distributor and rotor are way more susceptible to degradation than the older large cap HEI equipped vehicles. A lot of the later TBI trucks that had the electronic controlled EGR valve would end up having issues, or at least more so than the earlier vacuum controlled models. Also, as old as your bus is, I would take a peek to make sure the injector pods appear to be firing cleanly and not dribbling fuel. It’s a very good chance the throttle body may need freshening up. While I doubt you will see as impressive results on the ’93 model as what I was able to accomplish, I’m sure you can get some improvements just the same.

cttandy

iTrader: (12)

custm2500 - sounds like the same ole, same ole over here.

Still staying tuned to see what you can come up with.

My speedo isn't accurate, so I have no hard numbers. I did a full tune up on my truck and bumped the time 8 degrees at idle. It now has spark knock under load with ethanol mix fuel. Lucky for me there are still several local stations that sell straight gasoline.

I am seeing a much better idle, and off-idle response now. I am also seeing longer drive times on the same money spent on fuel. This makes me wonder why I didn't do this 8 years ago when I started driving this beautiful bundle of rust.

skyhighsami

iTrader: (8)

Please explain how I added fuel AND air to my diesel and my economy. Easier air in, easier air out more efficient.

jeffreycastgsx

Read your own statement, it doesnt makes sense. Thats a diesel, and its different. Easier air in, easier air out, more fuel in, more fuel out. Its more efficient at burning gas. If you want more MPG, leave it alone. Datalogs from some of my tunes ive done on peoples car say the same thing about the mpgs. Less restrictions, less mpg.

skyhighsami

iTrader: (8)

Using that logic a more restrictive exhaust would be the ticket to economy. Maybe if they put an 1 3/4 exhaust instead of a 3 1/2 on the Escalade it would get better than 9 MPG. How is a diesel much different than a gas burner in theory?

jeffreycastgsx

Im not gonna say a freer flowing exhaust will lose MPG, since i dont have proof, but a freer flowing intake tract is DEFINITELY gonna make MPG go down. Diesels naturally waste less gas. Diesel engines are completely different, on diesels you can make more power by just adding fuel, and if you add more air (which also leads to more power) you dont have to add more fuel. If you add more air in a gas then you have to add more fuel, unless you tune for it. Once any input (maf, map, and even the o2 sensors) in the pcm sees more air is going into the engine then the pcms strategy is to add more fuel, the reason we have closed loop, and short term/long term fuel trims. Dont tell me that you base your mpg results on the estimated mpg on the dash, there not accurate, and once a programmer or tuner is added then those numbers are null.