Mach 4s in, DD2s out-- pretty impressed!

[metal tech]

If you drive your truck everyday you'll get adjusted much quicker than I did. I usually drive my 92 Camaro to/from work(easier to find parking) everyday. I took a 580 mile round trip w/truck 2 weeks after installing the mach 4's. The throttle was as smooth as before the install, just have to adjust your foot movement since it takes less to do what you want. I only have the jerkiness on some of these paved paths that SC calls roads. One thing I didn't mention is the injectors smooted out the initial grabby feel of my SBC Con FE. The added power makes it feel smooth like stock.



Al

 

[rivercat]

a big rodger on the paths in SC.



the dirt road towns bring you back to the days of the DUKES getting chased by Roscoe P.







Another thing what is the fuel milage with the big setups in a dynamic way



Im sure the punk kids that love to smoke up town and run every gear up to the red line with the petal in the floor get bad milage with or without the big mods just cause of their driving style. .



on the other hand



Im sure bob w can honestly say his setup is better for his conditions in high altitude and pulling what he pulls up the passes he climbs...





My consern is that I will get setup big mad/4s/b1 and the every day slow grampa/respectable driving not using but 150 hp/quarter throttle low smoke will kill me down to 14 or 12 something like a PS or DM. I know clemsnow is having a milage loss but not sure if it was a other problem causing it or if he got it fixed or not. Im not doing the best anyway with the big tires and 4. 10s, but want to stay high at like 16-18 so I don't get the



"you spent all this money and now burn more fuel" speech from wife/mom everyone just kills some of the joy



Im sure that the emmissions changes killed us on these trucks compared to the 6bt and that they have fixed them in the 3rdgen motors so that you get more power and less fuel.



So what is the diffrence when do you burn more and when do you burn less.

 

[metal tech]

On the run from Sumter to Atlanta 75-80 mph 17. 84 mpg (hand calculated). The return trip SE Alabama-Sumter 75 mph max- 17. 94 mpg(hand calc). I did run the AC on max both ways.



Al

 

[Fishin Guide]

Just got back from Montana. M4,DDUFM, PDR35. Average speed over 615 miles 72. 35mph. No stops, filled up at the end of the trip. 22. 84 MPG going, 23. 06 MPG returning. I drove over during the day and AC was on for 2nd half of the trip. No AC on the return as I did it at night.



Always hand calc the milage, I don't even have one of those little computer thingys to lie to me.



Truck was running empty. Other than about 500lbs of misc gear in the bed. Bed has a rolltop cover on board and I have dino oil in everything, no synthetic at all.



265/75-16 tire with 65PSI front, 60PSI rear.



Dave

 

[rivercat]

so yall had in increase with the power mods or what are you trying to say?



what kind of power are you running at wheels est. ?

 

[Fishin Guide]

so yall had in increase with the power mods or what are you trying to say?



what kind of power are you running at wheels est. ?

I did see an increase in milage due to efficiencies gained from adding fuel and air to the enine. Also, running for a long duration with the cruise on in the fat portion of the powerband helps as well.



My truck made close to 400hp on a dynojet with the M4s, DDUFM run in EZ mode and the PDR35-12. I need a bigger housing to get better dyno numbers, but it spools so quick and with a lack of smoke, I have yet to make the change.



This was the way I ran it down the hiway on my trip. I have no idea what the power output would be with the DDUFM on 5x5 as I have not dyno'd in this configuration.



Dave



Edited cause I can't spell!

 

[Hohn]

OK-- just topped off the tank. 180 miles took 11. x gallons-- when hand calculated (I keep a calc in the console), it was 16. 3



This was ENTIRELY around town. Nothing but cold starts and short trips.



No added timing, just the M4s and stock electronics. I'm pretty sure that a Comp (with the added timing) would bump it up about 1 mpg or so. When I can swing the $$, I'll probably pickup a Comp and dangle the wire. Then I can get my timing and not HAVE to tap the wire unless I specifically wish to.



Thus far, I am very happy and somewhat surprised at the increases in fuel economy. I don't get a chance to make many extended highway runs, so city mpg is all I have to report for now.



JMO

 

[Bob Wagner]

Keep yer eyes peeled for a catcher to test for a couple of days :-laf , should have it by the weekend

 

[Hohn]

Bob, you Rascal!!



I've heard of Bait-and-switch, but never "bait-and-hook" for sales techniques



jlh

 

[Bob Wagner]

Bob, you Rascal!!



I've heard of Bait-and-switch, but never "bait-and-hook" for sales techniques



jlh

this is for your testing only, I will need the catcher back

 

[Fishin Guide]

I am curios how the special Catcher/ DDUFM/ M4/ cam/ 12V lift pump/ undetermined bottom charger combo would work! :-laf



Dave

 

[Hohn]

this is for your testing only, I will need the catcher back

Are you sure that you won't take a check in lieu?

 

[Clmsnow]

How much of a difference in EGT* between the DDII's and the Mach 4's?? I have II's right now and I am considering 3's or 4's, but want to know if my turbo will keep things in check.

 

[Bob Wagner]

justin, your pm box is full :{

 

[dslmacdown]

OK-- just topped off the tank. 180 miles took 11. x gallons-- when hand calculated (I keep a calc in the console), it was 16. 3



This was ENTIRELY around town. Nothing but cold starts and short trips.



No added timing, just the M4s and stock electronics. I'm pretty sure that a Comp (with the added timing) would bump it up about 1 mpg or so. When I can swing the $$, I'll probably pickup a Comp and dangle the wire. Then I can get my timing and not HAVE to tap the wire unless I specifically wish to.



Thus far, I am very happy and somewhat surprised at the increases in fuel economy. I don't get a chance to make many extended highway runs, so city mpg is all I have to report for now.



JMO

I beared witness to some of your "testing" :-laf :-laf I am impressed with how clean the injectors are, I would say the smoke is about the same as your old injectors. I filled up yesterday for about $62 :{ :{ it is a sad time when I am happy to pay $2. 23 at the Kum and Go.

 

[rivercat]

Can't wait to hear how the mad/ecm reacts with the 4s and stock turbo

 

[Hohn]

Me, too I should know pretty soon. Rumor has it that's it's coming today or tomorrow.

 

[Clmsnow]

How about the difference in EGT's???... (going from DDII's to Mach 4's)

 

[Hohn]

It's too early to say, because in it's present setup, the truck's ECM shuts off the fuel before anything can get too toasty.



The EGTs definitely get to the high side faster. After all, these ARE 150hp injectors-- not your milder injector for sure. Steady cruise EGTs are down slightly-- maybe 50 degrees.



It appears these sticks are netting me a considerable fuel economy improvement. Right now, my fuel needle is touching the F mark, and I have 104 miles on this tank so far (it would be here at about 80 miles before). Previously, I would be at the first hashmark below F at 116 miles. Now it hits that point at about 150 miles.



Highway mileage looks pretty exciting-- I can't wait for a long trip to test it.



Once I get some kind of boost fooler/chip/ECM or something, I can post how quickly EGTs head for meltdown. I'm betting it will flash 1600.



jlh

 

[shawn huizenga]

Well, I've a completely different setup than you I can post a few results from my experience with the 4's. I currently have around 12,000 miles on mine and note that the engine emits a light smoke until completely warm(and I mean completely). I just got back from a 5,000 mile trip driving empty with a 2500 shortbed, average speed 75-80mph with an average mileage of 17. 5 mpg. That's including the test runs up at dtt. The highest tank was about 18. 9mpg, 75mph average on level ground with the cruise set. I'm not sure what difference the eep cam, and ported head make on mileage, but that's what I got. Just thought I'd throw in my . 000002



Shawn