when i decided to make a few changes to my e99, drw 4x4, zf6, 3.73..... hybrid 205/30's, t4 up pipe kit , sxe 366/73-.91, hydra and after purchasing those i decided why not an adrenaline hpop. purchased all of it from full force diesel. had the up pipes thermal coated, exh manifolds thermal coated as well as the turbine housing. i figured, why not while i have it apart. i knew a couple guys with auto trans running the sxe 364.5 pulling toyhaulers down the innerstates, as i do with mine. finding info from others that pull campers was difficult. i ran php, 1023 and jelibuilt tunes. i had ilde quality issues so i had a few revisions and they helped but nothing cleaned it up. for some reason they were tuning for 80% tips rather then the 30% and all tuners kept asking if i was sure i recieved 30% tips, ffd assured me that i did and that there injs were good. drove it that way for a while until i couldn't stand it anymore and made a switch box to test the injectors. i have video's of those tests on you tube and i did perform a cold cranking comp test while i was there. i know that isn't saying much as a leak down test or even a running comp test would be far better but i was there and did. weakest cyl was 415 psi cold crank and strongest was 425 psi, truck just turned 142k miles yesterday.
the 366/.91 exh was great at 70 mph and up while towing. empty, pulling a hill in heavy tow mode, i could spool to 30 psi if i floored it. that would make a school bus dissapear so we just don't. that turbo reacts differently to a manual vs an auto. i have no idea why but imo, the 366-.91 is far better suited for an auto then a manual. at that time i was pulling a 2011 wp 295 fifthwheel toyhauler. 10,500 lbs loaded, 12'2" tall and 34' long. if i dropped down below 65 mph in 6th then it would lug and smoke, struggle to boost back up for a few seconds. on data logs it would make 1 psi by 1500 rpm but it lugged hard. at 1850 rpm it would spool to 10 to 15 psi pretty easy but by 1950 rpm it was what i considered very responsive. on flat ground, with cruise set at 73 mph pulling the toyhauler, it would cruise at say 10 psi until the hill and then it would spike to 35 psi faster then i could shut the cruise off. never went over 1200* egts though! that was running south oni35 through kansas from nebraska to oklahoma.
the real interesting part is that you cannot build more then 20 psi empty. i say this because it turned out, i had 4 very poor injectors from ffd. 2 of the 4 made no change to mfdes when shut off at idle. i replaced them with brand new 205/30s from bitteroot diesel and all idle issues were great again. switched to aa tunes and kept php tunes as well. 1023 were un usable from day one and jelibuilts didn't make much power or i should say as much as php tunes did. couldn't get over 25 psi boost with jelibuilts were phps would spike 35 psi.
even with 4 poor inj's i could still hit those boost levels with the sxe366-.91 exh with php tunes. that turbo was all top end with my manual trans so i finally switched to a sxe 363/68-.91 exh. i now can command 10 psi at 1500 rpm. i like to set the cruise at 72 or 73 mph while towing the toyhauler and at that rpm the 363 is very responsive and does not exceed 1200* even on a 96* ambient temp day at 1400' elevation. have not made another run to idaho so i have not been back up to 9k ' with this turbo.
with the new inj's and new tunes from aa, we drove 9 hrs to mt rushmore, towing the camper down 65 mph hwys and 73 mph on the innerstate. the last half of the drive was in 30 mph gusting winds. for the first time, since all the changes, with 8 good injectors that were actually flow tested, i was able to tow 9hrs in stockish mode! didn't need a tow mode to get the job done. we are at 1440' elevation here at home and i don't remember what mt rushmore or along the way was. it is higher then here though.
swapping from the 366/73-.91 to the 363/68-.91 moved spool up down a solid 300 rpm. the stock e99 turbo saw 1psi by 1200 rpm and was very responsive but lacked top end breathe while towing on the innerstate. the two i referenced above, with auto trans are far more responsive then i saw, while towing their campers and have larger inj's then i do. i put my old turbo up for sale for 550 and got some low ball offers so i boxed it up and put it in a cabinet. it would be interesting to see the diff a .84 exh would make with the 363 but i am happy with it where it is now and don't want to change them out just for grins and giggles.
i have no idea why you cannot build more then 20 psi. i am not saying it's the jelibuilt tunes but my experience with his tunes were similar, when compared to php tunes and now aa tunes. jelibuilts tunes were great for a manual trans vs php and the unusable 1023 tunes. aa has a similar tuning strategy for manual trans as well but still make more power.......imo.
i should probably mention, the other two auto trucks i referenced were 200 and 2001 models. i say this because the e99 pcm has fewer tuning cells and is more difficult to tune. that can make a difference but no idea how much.