How much milage does a person lose in getting to the 500HP mark with these 12V??

What are the most effective power adders??

Blygy

 

Well howdy...

The loss in mileage would depend on how much of that 500 ponies you are using. If you are a highway cruiser, your mileage "should" only be affected by timing and possibly the difference in turbocharger geometry.

The most effective adders.. Hmmm. Well the list IMHO is short.

370 Injectors or if you have the $$$ you can get F-1 EDM's made.
Turbo (differing opinions here of course) KSB1B or HX-40 equivalent
Fuel Cam Plate #10, #100 if you like to grind or #0
3k Governor Spring kit.

Intake and exhaust mod, ScottyII would be there for me.

Lookin at hoppin up a new addition????

J-eh

 

Yea sometime in the next year hopefully..

looking for a 98 12V dually ext cab 4x4 5 spd.

My buddy just picked up a 99 2500 and i gotts the bug again bad.. Might have to sell the 440 727 combo.

Yea.. Scottys fuel and air mods are on the short list along with Don's EDMs..

I'm hoping a plate, injectors and turbo will get in the 400 - 500 range.. then I gots to save for some serious mods like cam and such.. but Hopefully I will be able to play with this on as momma wants the new one left as is more or less.

Blygy

 

If anything higher hp increases mileage because you can stay in higher gears and get up to speed faster. If you get into flooring it though your mileage will go down. You don't use the added hp till you push the pedal down.

 

The way I priced it with PDR and other known vendors, Project-400 is gonna end up in the $4-5K range. That includes gauges, plate, GSK, AFC kit, clutch, exhaust, injectors, turbo, and of course SCOTTY II...

If you get too far into the 500 range, you would also be looking at upgrading the 5spd with larger input shaft and other upgrades. That would start getting pretty steep.

Just FYI...

 

Mileage can definately suffer if you select an injector that has a poor spray pattern at your intended cruising rpm..........don't go too big on the injector and you will be fine.......EDM's would be the way to go, IMO...........Many guys report a small mileage gain with Mach 1.5's and almost 100 hp on the 24v's!!.........sounds too good to be true but it seems to be the case..........I would say stay under a Mach 2.5......

 

i have around 450 rwhp, i get about the same miliage i got with the truck stock, 16 to 18 with a best of 20.47. i run 370 injectors, 16.2 timing, a bhaf,a #100 plate and a 14cm exhaust housing. making power is cheap, holding it is a whole nother thing. i would not suggest spending a dime on a 5 speed. they will just not take the abuse. i would swap in a 6 speed. i wish i did this before i droped the bucks on mine. i have a fully splined main shaft and a con fe 13.25 conversion clutch. i twisted off one input allready and i am scared to get on it now. i have a six speed and a southbend dual disk to go in it now. i just wish i spent the money for that in the first place. 370's, 100 bucks, 350 dollar ebay 5" exhaust,14cm exhaust was free from a friend, #100 plate, i showed everyone how to make them for free, timing kit was 250 but i have timed a few trucks to get that money back. power is cheap!!! rebuilt upgraded tranny1200 bucks, 13.25 conversion 1400 bucks. and it still will slip a bit with a 4th gear slam. 2600 bucks into something i am not happy with, i just wish i got the 6 speed from the get go. i know it won't shift as well but it should hold up. now the twins will be built for low dollar also and should shoot me up into the 600 plus range. and i will have the clutch and tranny to hold it.

 

"350 dollar ebay 5" exhaust"

Speaking of which, are the 5" exhausts that are 4" from turbo to muffler any good? This is all I can ever seem to find on eBay. Seems like I hear, <300hp = 3", 300hp-450hp = 4", 450hp+ = 5" but I haven't heard mention of the hybrid 5" exhaust. I would think a 4" downpipe is ok but all the way back to the muffler?!

 

mine is a 4" down pipe and as soon as it goes level with the frame goes to 5". i just put on a 5 because i knew i was going to twins. the place is out of oklahoma city i think. mike