5.0L Screamer Motor goes to the dyno. (w/ graphs & video)
10-03-2009, 12:15 PM
#181
Nordschleife Master
I've tuned my '80 S on the dyno and found 10 or 20 ponies (I forget!) just by tweaking the main adjustment screw and the distributor. So much more could be done with advance curves, WUR pressure and fuel pressure regulator(s). When I stand behind the car it's a bath of unburned hydrocarbons that makes my eyes burn. But I'm not an engineer at Porsche.
Kudos to the team for this result AND showing their work.
10-03-2009, 01:27 PM
#182
Rennlist Member
what main adustement screw on a 80 928 gave 10 to 20 hp???? I played with everything that could be played with with my 84, and didnt see much more than 2-3hp for major changes for timing and mixture.
certainly tuning is important. No question or challenge there. But, in dennis' case he got big hp before the tuning and after gained another 15hp or so. So, tuning was worth 15hp. Hey, I caught a lot of flak with the Holbert stroker engine for not tuning it professionally. However we did some tuning, as broad based as it was. fuel was good and safe and cam timing was optimized for my use racing. In the end, i got a safe motor that was adaquately powerful. sure, I might have got 400rwhp with some shark tuning (i.e. plus 25hp or something), but in the end, for my racing effort, the power wasnt the weak link, chassis, suspension, set up, tires , etc was. I got my 1.5 second consistantly taken off each tracks lap times for about 65hp gains. Point is, if you are looking to maximize hp for bragging rights and dyno-offs, do it all. If you just want the broad based gains, it sounds like we all know how to do that too now. intakes, cams and displacement changes all work great. Tuning puts the final touches on the numbers.
mk
certainly tuning is important. No question or challenge there. But, in dennis' case he got big hp before the tuning and after gained another 15hp or so. So, tuning was worth 15hp. Hey, I caught a lot of flak with the Holbert stroker engine for not tuning it professionally. However we did some tuning, as broad based as it was. fuel was good and safe and cam timing was optimized for my use racing. In the end, i got a safe motor that was adaquately powerful. sure, I might have got 400rwhp with some shark tuning (i.e. plus 25hp or something), but in the end, for my racing effort, the power wasnt the weak link, chassis, suspension, set up, tires , etc was. I got my 1.5 second consistantly taken off each tracks lap times for about 65hp gains. Point is, if you are looking to maximize hp for bragging rights and dyno-offs, do it all. If you just want the broad based gains, it sounds like we all know how to do that too now. intakes, cams and displacement changes all work great. Tuning puts the final touches on the numbers.
mk
And don't overlook that carmakers need to produce cars that meet emissions requirements. I was working on a GTS one day and when it was running in the garage it smelled like a steam iron. Just steam coming off hot metal.
I've tuned my '80 S on the dyno and found 10 or 20 ponies (I forget!) just by tweaking the main adjustment screw and the distributor. So much more could be done with advance curves, WUR pressure and fuel pressure regulator(s). When I stand behind the car it's a bath of unburned hydrocarbons that makes my eyes burn. But I'm not an engineer at Porsche.
Kudos to the team for this result AND showing their work.
I've tuned my '80 S on the dyno and found 10 or 20 ponies (I forget!) just by tweaking the main adjustment screw and the distributor. So much more could be done with advance curves, WUR pressure and fuel pressure regulator(s). When I stand behind the car it's a bath of unburned hydrocarbons that makes my eyes burn. But I'm not an engineer at Porsche.
Kudos to the team for this result AND showing their work.
10-03-2009, 01:42 PM
#183
Rennlist Member
I dont want to dig into the dyno comparisons, as they are all over the map. I wonder why I had such luck with a dynojet for 7 years of testing, to a mustang and back to the dynojet. I saw as little as 2-5hp difference. anyway, there are many reasons for variances. what I like about dynojets, is that they tell you how fast you can accelerate the rotating mass over time and speed. this is by definition, POWER. if you do it, you did it and you get a power figure. there is no debate. Sure, corrections are a dime a dozen, and that can skew the figures, but on that day, get the actual values and thats what you did. do it on a 80 degree near standard day, and thats your power.
as far as intake, heads cams, etc, there are a lot of factors. When you were comparing intake velocities, isnt that going to depend on displacement and number of cylinders, along with stroke to bore ratios and port sizing? (and rpm)
3 cars with 440rwhp. (I have actual graphs) one with 8 liters, 10 cylinders, 6000rpm, another with 3.8liters 9000rpm, and yet another 6.5liter with 6500rpm and 8 cylinders. Then, take a stock 928 from 20 years ago and look at its 5liter engine with a set of headers making 335rwhp . I still dont see such a stretch for Dennis' engine making 350rwhp and then tuned to 375rwhp for a new set of cams as the only major mod. By the way, dennis' 385rwhp is optimistic. that value was in the "noise" area of the graph which you cant count. generally, it was a peak of 375rwhp and before the tune was near 355rwhp.
as far as intake, heads cams, etc, there are a lot of factors. When you were comparing intake velocities, isnt that going to depend on displacement and number of cylinders, along with stroke to bore ratios and port sizing? (and rpm)
3 cars with 440rwhp. (I have actual graphs) one with 8 liters, 10 cylinders, 6000rpm, another with 3.8liters 9000rpm, and yet another 6.5liter with 6500rpm and 8 cylinders. Then, take a stock 928 from 20 years ago and look at its 5liter engine with a set of headers making 335rwhp . I still dont see such a stretch for Dennis' engine making 350rwhp and then tuned to 375rwhp for a new set of cams as the only major mod. By the way, dennis' 385rwhp is optimistic. that value was in the "noise" area of the graph which you cant count. generally, it was a peak of 375rwhp and before the tune was near 355rwhp.
By Mark Kibort
First of all this is complicated subject when you get right into it but relatively simple in reality, the air speed I refer to has zero to do with the MAF and it is confined to the head's ports, however the intake tract from the bellmouth needs to be considered as that is also very important.(Part of the package) It also has nothing to do with the amount of cylinders so it is not misleading in the slightest.
As to comparative acceleration it would be interesting if you would post your figures.
By Mark kibort
In my engine development story I saw basically zero gain from changing stock cams for cams that had 239 degrees duration @0.050" on the intake side (stock is about 217 degrees) so to see 30 hp at the wheels is a lot. The GT got a 10 hp increase. Think about this, to get a gain your cams must be limiting the airflow. The airflow from these heads in terms of needed capacity is excessive. Normally you don't want excessive airflow as it normally means that you will have slower air speed, that is you are passing up extra volumetric efficiency through inertia ram effect.
If you have Phil Threshie article from the 928 Forum magazine he mentions that Mark Anderson put on much better flowing heads and saw little or no gain with the new high flow heads. Phil hypothesized that the (given he had found the manifold to be restrictive when flowed tested and bolted to the head) manifold was the cause of the lack of improvement. It may be whole or partly correct, Phil did have the right idea with tapered runners, they have proven to normally be superior to constant radius runners.
Erland *** who is a very respected engine builder has done a set of 4 valve 928 heads, he described them as huge and filled them in with epoxy, I have requested photos. As I mentioned the 4 V ports are around 2.42 sq" and from the program I have they may well be optimized around 1 sq" smaller, it is trial and error though. So port velocity may be very well just as important as the manifold restriction on the 4 V 928 engine.
Have a look at this website it will be worth your time if you want to find out more about port sizing and epoxy work. About the third of the way down when discussing the intake cycle, that is very pertinent.
http://www.mototuneusa.com/think_fast.htm
Read what he says about small fast flowing ports, that is the reason I made my 2V port for my stroker just under 2.20 sq" and it probably flows as well as a stock 4 V port on a per sq" of port area basis. In the end we will have to see how it runs on the engine to find out which is more efficient. Going back to my engine that saw no gain with the bigger cams, it may all be down to airspeed.
The data I took was that the engine at 6000 rpm was producing around 375 to 380 rwhp not at 7,000 rpm that makes a very big difference. Now as to not being that far away, have a look at these top end vehicles, compared to 197 psi for the 928 Screamer
McLaren F1 achieves 182 psi
Ferrari F430 achieves 172 psi
BMW M5 achieves 168 psi
Here is a graph of two engine masters winners
http://www.epi-eng.com/epi_general_i...ters_rules.htm
You will notice at peak power they have around the same BMEP as the Nascar engine, these are highly modified engines. Very High air speeds, note the epoxy in the manifold
http://www.popularhotrodding.com/eng.../photo_20.html
Jon Kaase actually has these heads cast to his design, note how small the ports are compared to the gasket.
http://www.popularhotrodding.com/eng.../photo_15.html
Now as to the dyno readings which i think is reasonable for this issue, the difference in the dynos can be huge and from the numbers i have seen the differences are so big it is not surprising there is conflict on this topic.
This fellow dynoed his car on a dynojet and Dyno Dynamics same day just across town within a couple of hours.
The Results:
ATP (Dynojet) - 275.8whp and 232.2 torque
Vishnu (DynoDynamics) - 224.7whp and 192.2 torque
That is a huge difference
Here's the link
http://forums.nasioc.com/forums/showthread.php?t=286440
A bit about shootout mode
http://www.towler.com.au/shootout.html
Another disbeliever about the differences in the losses, here's a list of other cars dynoed on the DD
Ferrari Modena makes 280 whp
Ferrari F430 makes 355 whp on Dynamics
M3 E36 makes 225 whp
M3 E46 makes 245 whp
M5 E39 makes 280 whp
E46 330ci makes 150 whp.
http://www.m5board.com/vbulletin/e34...s-results.html
This thread talks about a correction factor needed to compare the DD to a Dynojet, I had to laugh at that one, sorry.
http://www.efi101.com/forum/viewtopi...43172d975a61b9
Greg
First of all this is complicated subject when you get right into it but relatively simple in reality, the air speed I refer to has zero to do with the MAF and it is confined to the head's ports, however the intake tract from the bellmouth needs to be considered as that is also very important.(Part of the package) It also has nothing to do with the amount of cylinders so it is not misleading in the slightest.
As to comparative acceleration it would be interesting if you would post your figures.
By Mark kibort
In my engine development story I saw basically zero gain from changing stock cams for cams that had 239 degrees duration @0.050" on the intake side (stock is about 217 degrees) so to see 30 hp at the wheels is a lot. The GT got a 10 hp increase. Think about this, to get a gain your cams must be limiting the airflow. The airflow from these heads in terms of needed capacity is excessive. Normally you don't want excessive airflow as it normally means that you will have slower air speed, that is you are passing up extra volumetric efficiency through inertia ram effect.
If you have Phil Threshie article from the 928 Forum magazine he mentions that Mark Anderson put on much better flowing heads and saw little or no gain with the new high flow heads. Phil hypothesized that the (given he had found the manifold to be restrictive when flowed tested and bolted to the head) manifold was the cause of the lack of improvement. It may be whole or partly correct, Phil did have the right idea with tapered runners, they have proven to normally be superior to constant radius runners.
Erland *** who is a very respected engine builder has done a set of 4 valve 928 heads, he described them as huge and filled them in with epoxy, I have requested photos. As I mentioned the 4 V ports are around 2.42 sq" and from the program I have they may well be optimized around 1 sq" smaller, it is trial and error though. So port velocity may be very well just as important as the manifold restriction on the 4 V 928 engine.
Have a look at this website it will be worth your time if you want to find out more about port sizing and epoxy work. About the third of the way down when discussing the intake cycle, that is very pertinent.
http://www.mototuneusa.com/think_fast.htm
Read what he says about small fast flowing ports, that is the reason I made my 2V port for my stroker just under 2.20 sq" and it probably flows as well as a stock 4 V port on a per sq" of port area basis. In the end we will have to see how it runs on the engine to find out which is more efficient. Going back to my engine that saw no gain with the bigger cams, it may all be down to airspeed.
The data I took was that the engine at 6000 rpm was producing around 375 to 380 rwhp not at 7,000 rpm that makes a very big difference. Now as to not being that far away, have a look at these top end vehicles, compared to 197 psi for the 928 Screamer
McLaren F1 achieves 182 psi
Ferrari F430 achieves 172 psi
BMW M5 achieves 168 psi
Here is a graph of two engine masters winners
http://www.epi-eng.com/epi_general_i...ters_rules.htm
You will notice at peak power they have around the same BMEP as the Nascar engine, these are highly modified engines. Very High air speeds, note the epoxy in the manifold
http://www.popularhotrodding.com/eng.../photo_20.html
Jon Kaase actually has these heads cast to his design, note how small the ports are compared to the gasket.
http://www.popularhotrodding.com/eng.../photo_15.html
Now as to the dyno readings which i think is reasonable for this issue, the difference in the dynos can be huge and from the numbers i have seen the differences are so big it is not surprising there is conflict on this topic.
This fellow dynoed his car on a dynojet and Dyno Dynamics same day just across town within a couple of hours.
The Results:
ATP (Dynojet) - 275.8whp and 232.2 torque
Vishnu (DynoDynamics) - 224.7whp and 192.2 torque
That is a huge difference
Here's the link
http://forums.nasioc.com/forums/showthread.php?t=286440
A bit about shootout mode
http://www.towler.com.au/shootout.html
Another disbeliever about the differences in the losses, here's a list of other cars dynoed on the DD
Ferrari Modena makes 280 whp
Ferrari F430 makes 355 whp on Dynamics
M3 E36 makes 225 whp
M3 E46 makes 245 whp
M5 E39 makes 280 whp
E46 330ci makes 150 whp.
http://www.m5board.com/vbulletin/e34...s-results.html
This thread talks about a correction factor needed to compare the DD to a Dynojet, I had to laugh at that one, sorry.
http://www.efi101.com/forum/viewtopi...43172d975a61b9
Greg
10-03-2009, 02:18 PM
#184
Nordschleife Master
10-03-2009, 04:05 PM
#185
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Sorry, I am not fluent enough in BMEP, although Jim has tried over and over to educate me about this, to argue one way or the other. You guys can have fun with that. All I know is that the dyno results were very consistent from one session to the next (i.e., the baseline run on the next session produced essentially the same results as the end run of the previous session) and this dyno produced very conservative (low) results with other cars we have tested there and elsewhere. So, I don't think the results are due to user error or are inflated. Sorry to be so unsophisticated. I know these things are subject to error commonly. Anyway, I just like to turn wrenches. Maybe Jim will jump in, but he does not like to get into these kind of back and forth rehashes. Besides, he has some plans for another motor that will probably cause a total Rennlist meltdown if/when results are posted. We're just having fun.
10-03-2009, 05:05 PM
#186
Nordschleife Master
What are these BMEP numbers used for / what should they be used for?
John Kuhn's car is between 250-300 psi BMEP for basically the entire rev range from 3000rpm to 5500 rpm. I was planning to end up at around 275 psi. Jeff Hartman's 2.1 liter Turbo MR2 evaluates at about 550 psi BMEP. This from a short dyno pull with race gas and 31 psi boost.
According to Hartman's book, 460-500 psi BMEP is the practical limit for sustainable periods in conventional gasoline engines. He explains in more detail:
"Unquestionably, conventional gasoline engines can survive delivering 2.0 to 2. lb-ft torque (average MEP) per cubic inch from nitrous boost (305 lb-ft on a 2.0-liter engine), or 3.5 to 4.0 lb-ft with alcohol-gasoline fuel blends, and thoroughbred racing engines have definitely survived delivering 4.0 horsepower per cubic inch (about 244 horsepower per lite). For perspective, consider that a de-boosted version of GM Racinh's turbocharged 2.0-liter Ecotec drag powerplant set several land speed records at Bonneville running at approximately 750 horsepower (6.15 horsepower per cubic inch), down from the 1,200 to 1,400 horsepower available at higher boost in short-duration drag racing (11.5 horsepower per cube!)."
John Kuhn's car is between 250-300 psi BMEP for basically the entire rev range from 3000rpm to 5500 rpm. I was planning to end up at around 275 psi. Jeff Hartman's 2.1 liter Turbo MR2 evaluates at about 550 psi BMEP. This from a short dyno pull with race gas and 31 psi boost.
According to Hartman's book, 460-500 psi BMEP is the practical limit for sustainable periods in conventional gasoline engines. He explains in more detail:
"Unquestionably, conventional gasoline engines can survive delivering 2.0 to 2. lb-ft torque (average MEP) per cubic inch from nitrous boost (305 lb-ft on a 2.0-liter engine), or 3.5 to 4.0 lb-ft with alcohol-gasoline fuel blends, and thoroughbred racing engines have definitely survived delivering 4.0 horsepower per cubic inch (about 244 horsepower per lite). For perspective, consider that a de-boosted version of GM Racinh's turbocharged 2.0-liter Ecotec drag powerplant set several land speed records at Bonneville running at approximately 750 horsepower (6.15 horsepower per cubic inch), down from the 1,200 to 1,400 horsepower available at higher boost in short-duration drag racing (11.5 horsepower per cube!)."
10-03-2009, 10:50 PM
#187
By IcemanG17
Thanks for posting Brian, how much rear wheel power do you have and on what type of dyno was it tested?
Mark K can you post your acceleration figures please? If your power figures are correct you will both be faster than the GT3RS.
Greg
Messed up (power brake) Good
0-10 1.18 .82 1.19
0-20 2.24 1.85 2.04
0-30 3.39 3.02 3.03
0-40 4.73 4.26 4.00
0-50 6.01 5.54 5.03
0-60 7.45 6.92 6.19
0-70 ----- 8.92 7.58
0-80 ---- 11.23 9.18
0-90 ----- ---- 10.93
0-100- --- ---- 13.58
0-1/4 ----- ---- 14.44 @103.3mph
WHP 194--205 -260
0-10 1.18 .82 1.19
0-20 2.24 1.85 2.04
0-30 3.39 3.02 3.03
0-40 4.73 4.26 4.00
0-50 6.01 5.54 5.03
0-60 7.45 6.92 6.19
0-70 ----- 8.92 7.58
0-80 ---- 11.23 9.18
0-90 ----- ---- 10.93
0-100- --- ---- 13.58
0-1/4 ----- ---- 14.44 @103.3mph
WHP 194--205 -260
Mark K can you post your acceleration figures please? If your power figures are correct you will both be faster than the GT3RS.
Greg
10-03-2009, 10:56 PM
#188
By Mark kibort
Mark they are not all over the place, the DD dyno in shootout mode gives consistent results which are around 15% to 23% lower than a Dynojet. That is why when the DD is sold in the States the operators have the ability to put in a Dynojet correction factor, not a weather correction factor just a multipier (when not in Shootout mode) to make the customer happy. Dynojet is the standard in the States and as such if you start giving people low numbers they don't like it and won't come back, pretty simple. I take you never read any of the links on this.
Greg
I dont want to dig into the dyno comparisons, as they are all over the map. I wonder why I had such luck with a dynojet for 7 years of testing, to a mustang and back to the dynojet.
Greg
10-03-2009, 11:08 PM
#189
A thing about airspeed, given none of the responders seem to take this on board, If you have a port the size of a storm water pipe, it will flow plenty on the flow bench wont it. How much power will it make if it was your port? Please answer that.
Also these top engines have their induction and exhausts tuned into what the engineers thinks is the best helmholtz range, the bigger the port the less the helmholtz effect. With slow airspeeds this effect cannot be utilized effectively or at all in some cases. Just getting to 100% efficiency is not easy, let alone 120%
Now lets be clear I am not picking on anybody but given the responses to date this is a subject that needs to be discussed. Please explain to me how a higher than 100% volumetric efficiency occurs. Give it some thought and go back to this link for some decent information on the topic.
http://www.mototuneusa.com/think_fast.htm
Greg
Also these top engines have their induction and exhausts tuned into what the engineers thinks is the best helmholtz range, the bigger the port the less the helmholtz effect. With slow airspeeds this effect cannot be utilized effectively or at all in some cases. Just getting to 100% efficiency is not easy, let alone 120%
Now lets be clear I am not picking on anybody but given the responses to date this is a subject that needs to be discussed. Please explain to me how a higher than 100% volumetric efficiency occurs. Give it some thought and go back to this link for some decent information on the topic.
http://www.mototuneusa.com/think_fast.htm
Greg
10-03-2009, 11:55 PM
#190
Nordschleife Master
Oversized ports and too big (i.e., late closing) cams are going to be a nightmare from volumetric efficiency point of view.
My head guy has kept the cross-sectional area very close to stock, precisely for the reasons you list. (Keeping the stock intake valve size, too.)
Now lets be clear I am not picking on anybody but given the responses to date this is a subject that needs to be discussed. Please explain to me how a higher than 100% volumetric efficiency occurs. Give it some thought and go back to this link for some decent information on the topic.
Last edited by ptuomov; 10-04-2009 at 08:46 PM.
10-04-2009, 12:24 AM
#191
Hi Tuomo, thanks for your reply, can you do me a favour and work out what the airspeed will be on a stroker of say 6.5 liters and at 6500 and 7000 rpm and then do what Mike's 7 liter stroker would be doing at 7000 and 7500. The reason is that basically the ports on the strokers are not really opened up at all and as such I think there is something wrong somewhere with the port sizing. That is either mine or yours is wrong.
As I said I believe the S4 type port to be around the average CSA of 2.42 sq". Becareful as that is the average, Pipemax gives a much lower airspeed number to what you are getting. Also the guys that do my work say that to achieve a volumetric efficiency of 105% on a 90 degree port (like a Chevy) you need at least 270 feet per second (@28") of average velocity.
Now if I recall correctly, Erland said that the F1 ports run at over 400 feet per second and while I am giving away secrets he told me that I should run part of my Porsche port at 142 metres a second or 465 feet per second. It will be interesting if his customer can find the photos of that port he did. As for gains, again, trial and error and Erland may know as he has done this.
Greg
As I said I believe the S4 type port to be around the average CSA of 2.42 sq". Becareful as that is the average, Pipemax gives a much lower airspeed number to what you are getting. Also the guys that do my work say that to achieve a volumetric efficiency of 105% on a 90 degree port (like a Chevy) you need at least 270 feet per second (@28") of average velocity.
Now if I recall correctly, Erland said that the F1 ports run at over 400 feet per second and while I am giving away secrets he told me that I should run part of my Porsche port at 142 metres a second or 465 feet per second. It will be interesting if his customer can find the photos of that port he did. As for gains, again, trial and error and Erland may know as he has done this.
Greg
10-04-2009, 12:33 AM
#192
Race Director
This was done 100% stock plus RMB.....so the best dyno runs on this setup were 267-272-279whp....in 3rd gear on a mustang dyno.....it kept making power pretty high in the powerband for an S4.....far beyond 6000rpm...which a stock S4 should not do.....my guess is the cams are retarded 3' but even that won't explain the high top end and relative low bottom end torque....
With Carls intake spacers and a bit more RPM it made 286 whp on the same dyno with similar weater conditions
I do think Sharky is VERY strong....far stronger than any other 928 automatic I've ever been in....well except for Bills with boost!!
10-04-2009, 12:48 AM
#193
Tuomo and others that are interested, as to the explanation that the tuning (adjusting air fuel) is the reason for the high BMEP, well that can not be the case. To achieve with a 5 litre engine at 6,000 rpms with power in the range of 440 to 450 hp that requires approx 120% volumetric efficiency. Volumetric efficiency has nothing to do with the air fuel ratio. It is assumed that the engine is tuned properly when you talk efficiency numbers let alone ones that are over 100% efficiency.
Greg
Greg
10-04-2009, 03:03 AM
#194
Rennlist Member
Id did both of those things to the same level and only saw about 3-4 hp. (i.e. 3 degrees total advance and 13.5 to 12.5:1 AFR.
I wonder what you did that was different to get 5x the HP gains.
mk
I wonder what you did that was different to get 5x the HP gains.
mk
10-04-2009, 03:03 AM
#195
By IcemanG17
Brian, that seems pretty reasonable hp number especially given your accel times. I have around 310 rwhp, btw I put in your best time, it will be interesting to compare Mark's time.
----GT3 Greg's928 Brian's 928
0-30 1.4 ___2.3_____3.0
0-40 1.9___ 3.0_____4.0
0-50 2.6 ___4.5_____5.0
0-60 3.9____5.4____6.2
0-70 4.8 ___6.9_____7.6
0-80 5.8 ___8.1_____9.2
0-90 7.7 ___9.4_____10.9
0-100 9.2 __10.9____13.6
Greg
Greg
This was done 100% stock plus RMB.....so the best dyno runs on this setup were 267-272-279whp....in 3rd gear on a mustang dyno.....it kept making power pretty high in the powerband for an S4.....far beyond 6000rpm...which a stock S4 should not do.....my guess is the cams are retarded 3' but even that won't explain the high top end and relative low bottom end torque....
With Carls intake spacers and a bit more RPM it made 286 whp on the same dyno with similar weater conditions
I do think Sharky is VERY strong....far stronger than any other 928 automatic I've ever been in....well except for Bills with boost!!
This was done 100% stock plus RMB.....so the best dyno runs on this setup were 267-272-279whp....in 3rd gear on a mustang dyno.....it kept making power pretty high in the powerband for an S4.....far beyond 6000rpm...which a stock S4 should not do.....my guess is the cams are retarded 3' but even that won't explain the high top end and relative low bottom end torque....
With Carls intake spacers and a bit more RPM it made 286 whp on the same dyno with similar weater conditions
I do think Sharky is VERY strong....far stronger than any other 928 automatic I've ever been in....well except for Bills with boost!!
----GT3 Greg's928 Brian's 928
0-30 1.4 ___2.3_____3.0
0-40 1.9___ 3.0_____4.0
0-50 2.6 ___4.5_____5.0
0-60 3.9____5.4____6.2
0-70 4.8 ___6.9_____7.6
0-80 5.8 ___8.1_____9.2
0-90 7.7 ___9.4_____10.9
0-100 9.2 __10.9____13.6
Greg