M90 MPX-S Dyno Verified 400hp+

XR7 Phillip

Registered User
3.8L 5spd with MPX-S @ 20% OD with approximately 19psi on pump gas and methanol.

Phil 401rwhp dyno.jpg

Dyno video


11.95 time slip from the end of last season.

11.95 timeslip R.jpg
 

KMT

Registered User
Very nice - any chance we can learn what kind of $$ that level of performance goes for these days, thanks.

Ken
-=-
 

no164ford

Registered User
Congrads see the od helped out I run 30% now the coated rotors did not like it at first but after they broke in the extra 10% helped alot shaved off 2 tenths and car would no longer hook in the 60'

Congrats.

Hope the t56 gets it quicker.
 

Magnum Powers

Registered User
Great results, Congratulations!!!! Do you mind sharing the engine build and other details related to power performance?

Cheers,
Charles
 

XR7 Dave

Registered User
Great results, Congratulations!!!! Do you mind sharing the engine build and other details related to power performance?

Cheers,
Charles

The engine is nothing special. It's a basic 3.8L with a good set of ported heads. The cam is aggressive but not much different than a lot of other people are running. We haven't flowed the heads, but I'm guessing somewhere around 220/170cfm. The cam is a solid roller design but it's not a high rpm profile. It's solid roller for reliability reasons only. I feel that valve float and bounce at higher rpms and higher boost levels is a big problem with these motors so we wanted to be sure and run ample valve spring pressure to avoid that.

Other than a responsibly built motor, the rest of the performance recipe is a 3 legged stool.

1) Supercharger. The blower itself is of major importance here, and the abradive coated rotors are even more so. This is an out of the box MPX with the new rotor pack properly clearanced and broken in to where the blower runs smooth and quiet (relatively speaking). With that, the ability to make nearly 20psi of boost with 20% OD is one of the most important factors in this build. We could have made the same boost with the MPX at 30% OD, but in our experience increases in boost without an increase in OD results in approximately double the HP gain per pound of boost. We feel that this boost level and OD level represent a more or less ideal balance for this engine and this supercharger. This is particularly relevant when you consider that this motor sees 6800rpm at the track and has no signs of belt slip. The belt speeds that would be encountered at that rpm and 30% OD would make belt control very difficult. In a whole season of racing and dyno, etc., we are still using all the same set of belts so we are comfortable with this OD level.

2) Cooling. We use a very large front mounted intercooler along with alcohol injection to keep air charge temps under 100degF throughout an entire 1/4 mile pass. We initially used a large 3" core but found that to be insufficient so we are currently using a 4"x24"x12" core mounted outside the engine bay (right behind the bumper).

3) Tuning. There is no magic here, but having 20psi on tap from 2500rpm on up means that you must be aware of the engine's detonation tendencies and have fuel and an ignition advance curve that match that requirement. You can't just throw xx deg of timing in and expect xxx results. Each motor is different and at 20psi your margin of error (especially on pump gas) is small. We tune specifically to avoid detonation in the mid range then bring in our more aggressive tune on the top end for more HP when it is safer to do so.

That is the three legged stool that supports this power level.

The only other thing I will add, is that it is no small thing to be aware that this motor does this with stock exhaust manifolds, emissions legal cats, and a full rear exit, quiet exhaust system. The car is fully streetable, is daily driven, and passes OH E-check with flying colors.
 

Magnum Powers

Registered User
Congrats

Thanks for the break-down Dave! The combo is a great streetable setup for daily drivers on pump gas, seems there would be a lot of SC'ers wanting to copy that combo.

Cheers,
Charles
 
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Magnum Powers

Registered User
Tweeking out a bit more

Dave, I ported Kevin's MPx that helped him a lot, we might want to consider minor porting at this point, could pick up some even with 20% overdrive. When I developed the porting for the MPx my goal was to flow more air then a ported late model M90 without decreasing boost below 10,000 rpms. When I finalized the MPx port design it had greater airflow above 9,000 rpm then my best M90 port job. However there is more airflow to be had with some minor porting. If you would like to consider this let me know.

Cheers,
Charles
 

kenewagner

SCCoA Member
Nice numbers and with stock manifolds. Why did the run get cut short? Looks like it was still heading north on the dyno sheet

Ken
 

XR7 Dave

Registered User
Nice numbers and with stock manifolds. Why did the run get cut short? Looks like it was still heading north on the dyno sheet

Ken

That's a good question Ken and it segue's right into our philosophy on performance and dyno numbers. We are not obsessed with dyno numbers, we just wanted to demonstrate that this M90 combo is capable of repeated and consistent 400+rwhp. That dyno pull represents the first real time out for the car this year, without any more tuning or tweaking than it had last fall when it ran 11.95. Phil's real goal is to see how fast he can make it at the track, and not so much how much HP he can make on the dyno. We will dyno again later, and I expect there are a few more HP in it, but that is something for another day.

Charles, we have talked about having you port the case, but frankly this particular blower runs so well we don't want to take it apart. I have another MPX here that you already ported for me a couple years ago that we have considered sending to you for a rotor upgrade. This way we can also run the two blowers back to back on the same day like we did with this blower vs. a stock MPX when we first tested the new rotor pack.
 

XR7 Dave

Registered User
Very nice - any chance we can learn what kind of $$ that level of performance goes for these days, thanks.

Ken
-=-


That's a loaded question. If you have a stock SC and want to drop plastic and have it all done, the cost is pretty high. But, if like Phil you take your time, shop around, and spend wisely, it's not that bad. It took Phil 3 years, patience, a lot of weekend work, and all his spare cash to get it done.
 

1FSTBRD

Registered User
The only other thing I will add, is that it is no small thing to be aware that this motor does this with stock exhaust manifolds, emissions legal cats, and a full rear exit, quiet exhaust system. The car is fully streetable, is daily driven, and passes OH E-check with flying colors.

This build already seemed impressive enough, but this quote from you really made this build that much better. My goal is to build a faster SC, but with quiet mufflers and have it be a daily driver, as well.
 

Mike8675309

Registered User
Very nice build. The kind of power that feels good anywhere you go, and in any gear. Plus you don't have to worry about it blowing up on the way to the ice creme shop.
 
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