My MPD S475 Kit.

[Wayne]

From the graphs it doesnt look like it helped out at all besides spooling slower and power fell off right after 3500rpms

power fell off after 3500 likely due to back pressure and air flow capability of the turbo at elevation. an 82 mm precision turbo we tested later in the day carried the power band @ 700 rpms past where this one fell off.

stock heads?

heads have heavy duty springs, but stock flow

aaron had it in his race truck 2 years ago and could never get it to spool even with a vgt turbo than they switched it out to the stage 2 which still spooled slower than stock cam from what i remember

The original cam in the built motor Aaron had started out as a stage 3, then switched to a stage 2. Too much valve overlap (causing compression drop) for lighting the turbos he ran in a reasonable amount of time The one in Tadd's truck is a stage 2+, which is stage 2 duration (no valve overlap) with stage 3 lift. The cam in the engine only hurts power below 2000 rpm's, but carries the power band much further than a stock cam. Seeing as how at this altitude the S475 doesn't start to build much boost until 2500+ rpm's it's hard to consider the cam as problematic for the setup.

We have run the stage 2 cam in a good handful of 6.0's and 6.4's with excellent street manners at both low and high rpm's. It is by no means a dramatic power loss at less than 2000 rpm's with properly sized turbos. For guys running big turbos, who have stock stall converters, and have difficulty lighting their charger/chargers before their cam will have a bigger problem if the converter isn't loosened properly.

Cruising at 2000 rpm's, the S475 setup only builds about 2 psi of boost. When cruising down the freeway at 2500 rpm's, and you mash the throttle there's a good amount of smoke (see vids posted previously), but HO-LEE-CRAP! The truck really sucks you back in the seat at that point (what do you expect? it's 750+ hp, and the truck is considerably light (SCSB).

The engine definitely has more fuel than the S475 can use at this altitude running "extreme race" programming, which is why the power dropped off going with the more agressive tuning. With custom tuning I'm sure a little more power could be squeezed out of it. Keep in mind though, the testing wasn't to prove how amazing the MPD setup is. This testing was done to compare the turbo included in the kit with a comparable precision unit. Hopefully this info helps people understand.

 

[Giddy-Up-Go]

I might have missed it... but what was the peak power of the Precision vs. the Bulls-Eye?

 

[Erikclaw]

I might have missed it... but what was the peak power of the Precision vs. the Bulls-Eye?

What's up Garret? Don't see you out here often.

 

[Powerstroked162]

I might have missed it... but what was the peak power of the Precision vs. the Bulls-Eye?

I think the Precision turbo put 50hp on the Bullseye at peak

 

[Dzchey21]

I think tadds going to.do.some.more testing on the boost an back.pressure of both turbos with some different sensors to make sure the results were accurate before posting anything. I set tadd up with a dashdaq harness so we will see

 

[jdgleason]

I might have missed it... but what was the peak power of the Precision vs. the Bulls-Eye?

27 horse peak, about 100 horse at 4k rpm

 

[Craig@MFI]

And what were the exact specs on this precision turbo

 

[TurboM700]

Also whats the price difference between the two. If I can save a few grand and be 50hp less I'm ok with that.

Mike

 

[SEABEE08FX4]

And what were the exact specs on this precision turbo

I think its a 106mm if I'm not mistaken.

 

[jdgleason]

And what were the exact specs on this precision turbo

Ill get them when I get a chance.

I think its a 106mm if I'm not mistaken.

Its a 75mm. Its almost identical to a 475.

 

[mike@haller's]

we did two of them. one was a 75mm inducer the other was an 83mm inducer. Not sure on the rest of the specs.

 

[SEABEE08FX4]

Ill get them when I get a chance.


Its a 75mm. Its almost identical to a 475.

Ah I gotcha, so just a journal bearing vs ball bearing then ? What kind of wheel was in each turbo ?

 

[Powerstroked162]

27 horse peak, about 100 horse at 4k rpm

My bad, my geela. I was off a lil' bit lol

 

[mike@haller's]

Ah I gotcha, so just a journal bearing vs ball bearing then ? What kind of wheel was in each turbo ?

Im pretty sure they were all journal bearing.

 

[SEABEE08FX4]

Im pretty sure they were all journal bearing.

I didn't think precision did journal bearing turbos.

 

[mike@haller's]

I didn't think precision did journal bearing turbos.

I guess i better let tadd answer that then.

 

[BFT]

I think its a 106mm if I'm not mistaken.

You mean this 106

 

[Erikclaw]

Ridiculous!

 

[SEABEE08FX4]

You mean this 106

Not sure if that's the one I saw on facebook or not, I just assumed that was the one used. That's a monster though lol.

 

[idkillinit]

Haha that would never spool in single form.