BMW M5 Forum and M6 Forums banner

21 - 40 of 51 Posts

·
Registered
Joined
·
200 Posts
DI'd you connect a fueL pressure gauge during the runs? Maybe pressure drops off. Tuner maybe adding fuel in upper bins in attempt to compensate for dropping pressure? This gives the spike rich, then when pressure collapses enough, it goes lean? ForgiVE me if you already checked this.
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #23 (Edited)
DI'd you connect a fueL pressure gauge during the runs? Maybe pressure drops off. Tuner maybe adding fuel in upper bins in attempt to compensate for dropping pressure? This gives the spike rich, then when pressure collapses enough, it goes lean? ForgiVE me if you already checked this.
I've never but it's good to be done. Just ordered a new OEM fuel pressure regulator and then I'm going to test. I have all symptoms of a bad regulator - black smoke from the exhaust, cold start stalling and (maybe) gasoline drips out of the tailpipe but I'm still not sure about the last one. Also should check the oil dipstick and see if I can smell fuel on it.

Thanks!

Aeromotive is a such a piece of sh*t. You should replace it regardless lol
I was pretty happy with it until three failed dyno days. If I find it causes these headaches will be replaced ASAP.
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #24 (Edited)
Ok guys, I replaced the fuel regulator with a genuine one but no difference. We still reproduce the problem at 50 degrees and 90 degrees air temp so I'm sure the fuel pump doesn't overheat. Also if it overheats that would cause runing lean not rich I believe.

I have no idea what else to replace from a mechanical side.
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #26 (Edited)
Hard to start, black smoke, running rich? What about a stuck or leaking injector? I'd pull the rail off with the injectors attached, and turn the key on and see if anyone of them start leaking fuel out of the nozzle.

Chris
It starts up easily already. Injectors are brand new and also the issue appears just sometimes depending on something but no idea what. Today it happened in 3rd but not in 4th gear.
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #27 (Edited)
Wondering if the gas pedal sensor could be bad by a chance? I have a spare one from another M5 and considering to replace it, but doesn't look like this could cause that kind of issues. Also I have another one ECU. Does it worth to give a try?
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #28 (Edited)
My investigation shows sometimes Walbro fuel pumps cause running rich with stock fuel pressure regulators. It's possible Aeromotive to do the same. I already believe I need an aftermarket FPR... but first I'm going to test the fuel pressure.
 

·
Registered
Joined
·
12,768 Posts
My investigation shows sometimes Walbro fuel pumps cause running rich with stock fuel pressure regulators. It's possible Aeromotive to do the same. I already believe I need an aftermarket FPR... but first I'm going to test the fuel pressure.
I think others SC cars are using Walbro and Aeromotive without issues. Most people are using the stock FPR. I know I am, although I have a different fuel setup (stock fuel pump and BAP). Focusing on a faulty FPR makes more sense to me.

Good luck tracking down the issue.

Regards,
Jerry
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #30 (Edited)
I think others SC cars are using Walbro and Aeromotive without issues. Most people are using the stock FPR. I know I am, although I have a different fuel setup (stock fuel pump and BAP). Focusing on a faulty FPR makes more sense to me.

Good luck tracking down the issue.

Regards,
Jerry
Hi Jerry,

I already installed brand new genuine FPR with no result. That's the reason I want to measure the fuel pressure next. Any tips & tricks to do it properly? Looks like the car need to be with wide open throttle.

Otherwise you are right most people use stock FRP without troubles. I just can't accept it could be a software issue and still looking for a bad hardware.
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #31
Guys, just wanted to let you know we find out the issue comes from improper tune. We're working on the new tune at the moment so I hope I'll return with dyno results shortly.

Jerry (gsfent), many thanks especially to you for your support!
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #32
Sorry for the delayed update, folks. I'm happy to say wе achieved great results in August (95 degrees ambient temp):


And here it is a Dragy performance report with 100-200 km/h time:


Mods list for the future contains some good headers, 88 pulley and maybe an intercooler, but I'll need a retune as well. At last I expect about 600 whp.

Cheers,
Alex
 

·
Registered
Joined
·
3,636 Posts
Based on my past observations your torque numbers look a bit off.

How much boost, octane level and meth if any?
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #34
Based on my past observations your torque numbers look a bit off.
It's in Nm equal to 440 lb/ft

8 psi of boost, 100 octane fuel (euro), Aquamist HFS-3
 

·
Registered
Joined
·
3,636 Posts
Thanks for the clarification.

Seems a bit brave to tune for 100 octane, but perhaps the 100 octane gas station is close to you.

Are you running a mixture of meth or 100%?

Also, take this with a grain of salt. You will need more than headers and 2psi to hit 600 wheels. A good set of headers like Jed’s, Dinan’s, Evolve or Supersprint drop the manifold pressure 1-2psi and in turn will make more N/A power. This would most likely lead you to install a smaller upper pulley to bring the boost level up to where it was resulting gains of additional power.

I am not saying it’s impossible, just not likely on factory internals.


I am running 10psi on 91octane with 80/20 meth and I am not close to 600 wheel. I’ll admit my tune isn’t perfect and can be improved, but that’s max 10-15hp which will still leave me short of 600 wheel.

Food for thought....
 

·
Registered
Joined
·
12,768 Posts
Thanks for the clarification.

Seems a bit brave to tune for 100 octane, but perhaps the 100 octane gas station is close to you.

Are you running a mixture of meth or 100%?

Also, take this with a grain of salt. You will need more than headers and 2psi to hit 600 wheels. A good set of headers like Jed’s, Dinan’s, Evolve or Supersprint drop the manifold pressure 1-2psi and in turn will make more N/A power. This would most likely lead you to install a smaller upper pulley to bring the boost level up to where it was resulting gains of additional power.

I am not saying it’s impossible, just not likely on factory internals.


I am running 10psi on 91octane with 80/20 meth and I am not close to 600 wheel. I’ll admit my tune isn’t perfect and can be improved, but that’s max 10-15hp which will still leave me short of 600 wheel.

Food for thought....
I have similar numbers. Of course my TQ is in Lb./ft, not NM! :) But I pulled 534 rwhp with meth and a slipping clutch on a brutally hot summer day in south Florida. 92mm pulley. I am pretty sure 93 octane here is 100 octane across the pond. Frank Smith did a live tune while on the Dynojet, best tune I have ever had on any car. He said if someone could make a replacement intake for our plastic one out of something other than plasitic, we could pick up a bunch of power due to heat soak we currently have (anyone with a 3D printer out there?? :) :)).


As to 600 rwhp, you need about 700 crank. That to me is a sleeved block and turn up the boost to double digits (and perhaps knock a little off the static compression ratio). I think about 650 crank is all you can do on a stock block without worrying about blowing it up. Supposedly, Dinan tested to about that number and backed it off a little since they were backing their S3 with a warranty!

Regards,
Jerry
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #37 (Edited)
I'm running water and meth 50/50 ratio.

600 whp is my optimistic target because I have a friend in Germany (my tuner) who built a 620 whp M5 with ported heads, IC, meth, 9.5 psi, otherwise stock internals. It runs strong 15k miles already without any issues. Here it is the graph before porting the heads (704 crank):
safe image upload

Tuner says the key for the big numbers is correct cam timing leading to good throw out, no only huge boost. I don't want to port the heads for sure. Still considering the intercooler, because that involves another S/C bracket, pipes, new blow off valve etc. Planning to do a few dyno runs soon in the winter to see what power puts down when it's cold outside and see the real benefits from the intercooler if any.
 

·
Registered
Joined
·
3,636 Posts
I have similar numbers. Of course my TQ is in Lb./ft, not NM! :) But I pulled 534 rwhp with meth and a slipping clutch on a brutally hot summer day in south Florida. 92mm pulley. I am pretty sure 93 octane here is 100 octane across the pond. Frank Smith did a live tune while on the Dynojet, best tune I have ever had on any car. He said if someone could make a replacement intake for our plastic one out of something other than plasitic, we could pick up a bunch of power due to heat soak we currently have (anyone with a 3D printer out there?? :) :)).


As to 600 rwhp, you need about 700 crank. That to me is a sleeved block and turn up the boost to double digits (and perhaps knock a little off the static compression ratio). I think about 650 crank is all you can do on a stock block without worrying about blowing it up. Supposedly, Dinan tested to about that number and backed it off a little since they were backing their S3 with a warranty!

Regards,
Jerry
Jerry - You prove my point. I pulled similar numbers as you did with same conditions and issues with clutch. Fast forward to Better clutch, Jed’s headers, smaller Upper pulley and much more recommended by the same guy who did your tune and I gained a bit over 30whp. Hence my point about 600 wheel.

Just because one or two cars are able to hit those numbers, it does not mean every SC car has a potential of 600. Here is what i’d Say is the best way to get power out of e39 M5, find a way to keep that engine cool.

By the way, I have a better Intake and have not noticed performance gains.
 

·
Registered
Joined
·
12,768 Posts
Jerry - You prove my point. I pulled similar numbers as you did with same conditions and issues with clutch. Fast forward to Better clutch, Jed’s headers, smaller Upper pulley and much more recommended by the same guy who did your tune and I gained a bit over 30whp. Hence my point about 600 wheel.

Just because one or two cars are able to hit those numbers, it does not mean every SC car has a potential of 600. Here is what i’d Say is the best way to get power out of e39 M5, find a way to keep that engine cool.

By the way, I have a better Intake and have not noticed performance gains.
If I wasn't clear, I am definitely in agreement with you about 600 rwhp. I don't know of any cars that have 600 rwhp that have not been sleeved with the exception of the one posted above(absent a race motor by Dusty perhaps--they delete VANOs and are pretty secretive about that info! ;)). I don't necessarily doubt the results, clearly cooling is a priority (both IC and meth). But I am not sure I want to live that close to the edge. Did I miss the AFR's? That would be pretty important here.

Frank was guessing my setup had 30-50 rwhp with better clutch, so your numbers put him in the correct range. I don't know that the headers or my bigger TB's do much for adding HP with FI. I do have the option of 88mm from 92mm for another 1-1.5 psi of boost. Right now about 8-8.5.

Maybe we can run some hoses from the AC to the plastic intake ala Dodge Demon for better cooling??? LOL

Regards,
Jerry
 

·
Registered
Joined
·
1,442 Posts
Discussion Starter #40 (Edited)
Well I think my car achieved pretty good results with just 8 psi and stock headers compared to another similar setups. I'm sure 550+ is not a big deal with headers, new pulleys and a retune and I'm planning to proove it. Since one healthy M5 is capable of 600 wheel I don't see a reason why I couldn't?
 
21 - 40 of 51 Posts
About this Discussion
50 Replies
9 Participants
herrubermensch
BMW M5 Forum and M6 Forums
M5Board is the best forum community for information on the BMW M5 E60 (V-10), E39 (V-8), E34 (straight 6), E28, F90 and F10. Discuss performance, specs, reviews and more!
Full Forum Listing
Top