X51 Dyno Run
Burning Brakes
Joined: Dec 2006
Posts: 781
Likes: 1
First things first:
337.6 HP
287.6 TQ
Ok, so the numbers look pretty good but the circumstances were terrible. We are in one of the most violent winter storms I've experienced in N. California. Temperature is about 55 and winds are gusting to 60mph+. While we were testing, part of the roof blew off the building and shattered the rear glass on a car just outside the door. I'm talking really ugly typhoon stuff.
I arrived at the garage, got the car bolted up and ran a baseline run with all settings in normal and PSE plugged in. All runs were made in 5th gear which at 1.08 ratio is the closest to the ideal 1.0 (direct drive) in the tranny. The Dynapack dyno can run well over 150mph (no drum to turn) so it wasn't an issue.
After the first run, the PSM faulted and the ABS faulted and wouldn't let us engage Sport mode or toggle PSM, etc. The faults remained for the rest of the session, preventing any runs in Sport mode which was a big disappointment. The difference with PSE plugged or unplugged appears to be about 3-5HP in favor of unplugged. The tech struggled with the dyno software, settings and printer during the entire session which was not confidence inpiring... I don't think he fully understood how to set the steps and timing of the unit and ultimately gave me the session at no charge.
The last three runs are plotted in the graph below. They represent the best available circumstances - Engine running, throttle floored, PSM/ABS faults lit up, PSE unplugged, rain blowing into the engine comparment through the open garage door, tech seemingly satisfied the dyno was working properly.
Only 2 sets of data are shown on the graph so here are all three:
Run 1: 334.6HP, 281.3TQ
Run 2: 336.9HP, 286.7TQ
Run 3: 337.6HP, 287.6TQ
If I use the 1.16 drivetrain loss factor suggested by Mike at A.W.E., the best engine output is 401.9HP
MC
337.6 HP
287.6 TQ
Ok, so the numbers look pretty good but the circumstances were terrible. We are in one of the most violent winter storms I've experienced in N. California. Temperature is about 55 and winds are gusting to 60mph+. While we were testing, part of the roof blew off the building and shattered the rear glass on a car just outside the door. I'm talking really ugly typhoon stuff.
I arrived at the garage, got the car bolted up and ran a baseline run with all settings in normal and PSE plugged in. All runs were made in 5th gear which at 1.08 ratio is the closest to the ideal 1.0 (direct drive) in the tranny. The Dynapack dyno can run well over 150mph (no drum to turn) so it wasn't an issue.
After the first run, the PSM faulted and the ABS faulted and wouldn't let us engage Sport mode or toggle PSM, etc. The faults remained for the rest of the session, preventing any runs in Sport mode which was a big disappointment. The difference with PSE plugged or unplugged appears to be about 3-5HP in favor of unplugged. The tech struggled with the dyno software, settings and printer during the entire session which was not confidence inpiring... I don't think he fully understood how to set the steps and timing of the unit and ultimately gave me the session at no charge.
The last three runs are plotted in the graph below. They represent the best available circumstances - Engine running, throttle floored, PSM/ABS faults lit up, PSE unplugged, rain blowing into the engine comparment through the open garage door, tech seemingly satisfied the dyno was working properly.
Only 2 sets of data are shown on the graph so here are all three:
Run 1: 334.6HP, 281.3TQ
Run 2: 336.9HP, 286.7TQ
Run 3: 337.6HP, 287.6TQ
If I use the 1.16 drivetrain loss factor suggested by Mike at A.W.E., the best engine output is 401.9HP
MC
Those numbers are in line or a little better to what a non X51 997S does when you consider that a non X51 puts down around 300rwhp, so those numbers are really good.
Dave
Three Wheelin'
Joined: Feb 2006
Posts: 1,412
Likes: 4
Would be great to be able to compare this to MichaelL's AWE, plenum, Carg. etc. set up. Where are you Michael? Does anyone have figures for 997S? Think I recall seeing 310+ or so which would put Porsche's +26 hp in the ballpark.
Three Wheelin'
Joined: Feb 2006
Posts: 1,412
Likes: 4
Just for comparison, "666666" posting under "RPM Plenum sale" on 997 Forum is quoting these figures: stock 997S w Cargraphic exhaust 315/254. Same car w plenum added 327/270, all at rw. (NB: it is real difficult -impossible?- to compare different runs on same dyno let alone results from different dynos) This gets real interesting when you are considering stock, x51 and modding options. however. Personally, given deeper pockets, I would love to have an x51 motor. Gerry
Rennlist Member
Joined: Aug 2005
Posts: 602
Likes: 2
From: Panama City Beach, Florida
Prior to installing the plenum, the car made 321 rwhp. Power was essentially constant from 6600 to 7000 rpm. With a 16 % loss factor, this corresponds to 382 cshp. The plenum is probably good for 5 to 8 rwhp.
Please note that comparison with runs on a different dyno will not be valid. The adjustments for temperature & barometric pressure should make the local conditions to be of little consequence. These adjustments, however, are important, my car showed 340 rwhp before correction. The operator's skill in using the machine will have an effect on results. A dyno that connects directly to the wheel hubs might indicate greater power than a roller machine, due to smaller losses.
In any case, the indicated results for the X-51 motor look very impressive.
Please note that comparison with runs on a different dyno will not be valid. The adjustments for temperature & barometric pressure should make the local conditions to be of little consequence. These adjustments, however, are important, my car showed 340 rwhp before correction. The operator's skill in using the machine will have an effect on results. A dyno that connects directly to the wheel hubs might indicate greater power than a roller machine, due to smaller losses.
In any case, the indicated results for the X-51 motor look very impressive.
Race Car
Joined: Sep 2006
Posts: 3,862
Likes: 4
From: Colorado
With the correction factor, I think it was something like 360hp/308tq. Right on the money per Porsche's claims. An Evo made 512whp that same day...
Thread Starter
Rennlist Member
Joined: Nov 2001
Posts: 1,286
Likes: 4
From: CA
Addict
Rennlist Member
Rennlist Member
Joined: Nov 2002
Posts: 3,861
Likes: 38
Great news.
It confirms what some of us have maintained about the X51 package, it is worth the money and there is a significant difference over the stock S!! (IMO).
Probably the best (X51) overall 997 package for the daily commute!
It confirms what some of us have maintained about the X51 package, it is worth the money and there is a significant difference over the stock S!! (IMO).
Probably the best (X51) overall 997 package for the daily commute!
Race Car
Joined: Sep 2006
Posts: 3,862
Likes: 4
From: Colorado
Edit: Just noted the "commute" part - agreed w/997S w/X51 in that case. I'd still commute in a GT3 though.
Intermediate
Joined: May 2004
Posts: 42
Likes: 0
From: Manchester UK
The X51 numbers are very good to say the least. Good of H20NOO to post them.
I'd be VERY interested to see how much more the X51 motor gave if the standard cats were replaced with 200-cell motorsports (such as AWE). If a performace catalyst can give over 20BHP on the standard 'S' motor, it should in theory give even more on X51 - if the standard cats restrict the outflow from 355BHP they will be even more restrictive to a more powerful setup.
It could be possible with motorsport cats to equal GT3 power (maybe more)?. Now that would be a really exciting commuter / road / occasional trackday / practical / comfortable car! And it would sound incredible as 200-cell cats can add a lot of extra noise!
I'd be VERY interested to see how much more the X51 motor gave if the standard cats were replaced with 200-cell motorsports (such as AWE). If a performace catalyst can give over 20BHP on the standard 'S' motor, it should in theory give even more on X51 - if the standard cats restrict the outflow from 355BHP they will be even more restrictive to a more powerful setup.
It could be possible with motorsport cats to equal GT3 power (maybe more)?. Now that would be a really exciting commuter / road / occasional trackday / practical / comfortable car! And it would sound incredible as 200-cell cats can add a lot of extra noise!
Instructor
Joined: Jan 2003
Posts: 240
Likes: 0
From: Evergreen, CO
The ONLY thing stopping me from thinking the X51 is the answer, is that by the time you add it to a decently-optioned 997S (my last sticker was $94K), you're talking $110K+. For that money, I can get a GT3 with a claimed 415hp. Decisions, decisions....
Edit: Just noted the "commute" part - agreed w/997S w/X51 in that case. I'd still commute in a GT3 though.
Edit: Just noted the "commute" part - agreed w/997S w/X51 in that case. I'd still commute in a GT3 though.
Burning Brakes
Joined: Dec 2006
Posts: 781
Likes: 1
The X51 numbers are very good to say the least. Good of H20NOO to post them.
I'd be VERY interested to see how much more the X51 motor gave if the standard cats were replaced with 200-cell motorsports (such as AWE). If a performace catalyst can give over 20BHP on the standard 'S' motor, it should in theory give even more on X51 - if the standard cats restrict the outflow from 355BHP they will be even more restrictive to a more powerful setup.
It could be possible with motorsport cats to equal GT3 power (maybe more)?. Now that would be a really exciting commuter / road / occasional trackday / practical / comfortable car! And it would sound incredible as 200-cell cats can add a lot of extra noise!
I'd be VERY interested to see how much more the X51 motor gave if the standard cats were replaced with 200-cell motorsports (such as AWE). If a performace catalyst can give over 20BHP on the standard 'S' motor, it should in theory give even more on X51 - if the standard cats restrict the outflow from 355BHP they will be even more restrictive to a more powerful setup.
It could be possible with motorsport cats to equal GT3 power (maybe more)?. Now that would be a really exciting commuter / road / occasional trackday / practical / comfortable car! And it would sound incredible as 200-cell cats can add a lot of extra noise!
Dave