Partee Racing 4.6L S65 Stroker: 545 BHP on Engine Dyno

Title says it all. Matt Lambert, our in-house wunderkind tuner, just finished our first Motec tune of our 4.6L S65 stroker. 545 BHP, and I think it has a bit more in it. The 13.5:1 version on race gas should push 575-600. We shall see! Build terms can be reviewed in detail on our website, but here is the skinny:

Bore: 94mm--NBA (nothing but Alusil)
Stroke: 82.7mm
Custom Partee Racing 12.5:1 compression pistons made for us by JE
BMW S62 Rings
Stock length Carillo rods
ACL rod bearings with WPC treatment (couldn't achieve the clearances we wanted with BMW)
Lightly ported heads with Supertech valvesprings, retainers, locks and seats
Schrick 292/292 camshafts with stock hydraulic lifters
SRD oil pump gears
Stock injectors and coils
Tuned on a Motec M190 with full CAN-based control of throttle actuators and idle control valve.

This thing looks like a monster. Looking forward to seeing more. How "choppy" does it sound at idle?

Does this Motec unit support the knock-sensing functionality of the stock ignition coil packs?
If yes, do you have that calibration setup yet?
If not, do you have more traditional knock sensors? Or are forgoing them (for now?)?

(Just always curious about stand-alones and these crazy coils, and what I might do about it when I swap my S65 into another chassis...)

Eric335 wrote

This thing looks like a monster. Looking forward to seeing more. How "choppy" does it sound at idle?

Thanks to VANOS, it sounds bone stock in terms of chop. Having said that, while setting up the VANOS control profile, we had it idling with ~15* of intake advance and exhaust retard. Ole girl could have chopped down a forest lmao.


My inner degenerate wants to flash a “ghost cam” on my personal M3 LOL

For the record- with VANOS, it really is that easy if you want your car to chop at idle. The reason most of these cars sound a little more aggressive at startup & then the sounds smoothes is because you have several degrees of exhaust retard for a few seconds to help heat the catalytic converters.

BenFenner wrote

Does this Motec unit support the knock-sensing functionality of the stock ignition coil packs?
If yes, do you have that calibration setup yet?
If not, do you have more traditional knock sensors? Or are forgoing them (for now?)?

(Just always curious about stand-alones and these crazy coils, and what I might do about it when I swap my S65 into another chassis...)

Man you are on a hot streak with the great questions!

To my limited knowledge where standalone ECUs are concerned, no- there isn’t a standalone ECU that supports the OEM ionic knock detection system.

We have four traditional knock sensors fitted to the motor and wired to the Motec, and in all honesty, that is why we left some meat on the bones in terms of power output- not detecting knock on a dyno run is not proof that there is no knock happening, it is only proof that you are not detecting knock. The car this motor is going into will be using the OEM ECU which obviously has a far more sophisticated knock detection system. This will give us even more insight to our knock sensor tuning and will only continue to expand the knowledge base.

Chrisyphus wrote

Man you are on a hot streak with the great questions!

To my limited knowledge where standalone ECUs are concerned, no- there isn’t a standalone ECU that supports the OEM ionic knock detection system.

We have four traditional knock sensors fitted to the motor and wired to the Motec, and in all honesty, that is why we left some meat on the bones in terms of power output- not detecting knock on a dyno run is not proof that there is no knock happening, it is only proof that you are not detecting knock. The car this motor is going into will be using the OEM ECU which obviously has a far more sophisticated knock detection system. This will give us even more insight to our knock sensor tuning and will only continue to expand the knowledge base.

That's correct. Not even a Motec M190 can do it. I wonder if any of the Bosch professional units can do so. I would presume so, but it would come at an astronomically high price and a genetically attached equally expensive Bosch motorsport engineer. Before long, the cost would exceed the cost of the engine!

The question of where best to locate traditional Bosch knock sensors on an S65 when using an aftermarket ECU elicits quite a debate. In the "V" in between 1/2, 3/4, 5/6, and 7/8 would be ideal (following the S62), but the crowded V of the S65 makes that difficult. Some have used throttle actuator extender brackets that have a boss for the knock sensor, but I have my doubts as to whether that will provide a good noise-free or noise-filterable signal. So we mounted them on the existing bosses on the outside of the heads, one on each side about midway back and one pn each side at the very back. Anecdotally, the back mounted sensors provide the cleanest noise-free signal, but I cannot vouch for this yet. We will do more extensive knock sensor calibration and location testing on the next S65 stroker, which will hit the engine dyno this week.

Finally, if any team can figure out how to use an aftermarket ECU with BMW's ionic knock sensors in the stock ignition coils, it is Chris Knerr and Matt Lambert. Pure automotive porn: I just wanna watch!

Be well, and go fast.

--Peter

Chrisyphus wrote

To my limited knowledge where standalone ECUs are concerned, no- there isn’t a standalone ECU that supports the OEM ionic knock detection system.

Oh weird. I just assumed Syvecs did because of how often it is chosen as a solution. Now I really wonder why people choose it over anything else. Maybe they were just the first with enough IN/OUT and a decent S65 base tune? It kind of boggles my mind why it is so popular if it doesn't have this functionality...

BenFenner wrote

Oh weird. I just assumed Syvecs did because of how often it is chosen as a solution. Now I really wonder why people choose it over anything else. Maybe they were just the first with enough IN/OUT and a decent S65 base tune? It kind of boggles my mind why it is so popular if it doesn't have this functionality...

I just confirmed with one of my race clients that runs a Syvecs with his S65 (build by a well known builder across the pond that took three years and lasted 30 race minutes), and he confirmed that it does NOT read the stock ionic sensors, but rather, uses the same setup we used with the Moted, albet mounting only two sensors in the "V," one on each throttle actuator.

--Peter

In some ways that makes me very happy. This means I can likely get away with using my stand-alone of choice if I need to go that route (when I swap this S65 into a different chassis). I was not excited about having to learn a 5th or 6th stand-alone ecosystem that potentially wouldn't gel with me as much as my preferred system.

Loving this. As a stroker owner myself I’m glad there are companies out there still developing our platform. Just out of curiosity, how much would this total package cost? Also what kind of difference in hp numbers would it be if it was on stock cams?

Any thought of mounting knock sensors elsewhere for space/etc?

Gen 3 LS is in the valley, gen 4 LS moved to the sides of the block. I have no idea why or what this did for them, but they are there. Just a thought I had that may help - I am definitely not an engineer haha.

Outstanding numbers on pump gas!

Will this be able to be revved higher? 9k rpm?

good numbers, peak hp and torque right at 7.5K is expected on this displacement w/ the drop off to 8K being reasonable. pretty much ESS G1 type dyno graph.

really cool to see~