Dyno results: Stillen Headers
10-15-2003, 07:53 AM
#41
Senior Member
Join Date: Dec 2001
Location: Charlotte, NC
Posts: 1,687
As we all know, my plugs were bad.
I still found the car running rich, even at idle. The ECU is definitely compensating for the increased air flow. It appears (as stated before) that the algorithm for the air/fuel mixture is incorrect from the factory.
I'm running at a 9% reduction (in air) so that the car leans out the gas... at idle.
Starting at 4200-5000, I'm up to a 12% reduction (in air) so that the car leans out the gas even more.
There's not a single range where I'm not reducing the air input to the ECU because of the over-compensating algorithm.
I'm scheduled to get back on the dyno soon. I'll be tuning the car for regular street driving, then for race driving.
Screen shots from the E-Manage are available at:
http://maxima.theowensfamily.com/images/e-manage.jpg
Please note that the values listed are not my final values, but they are just an idea of how the unit works.
In the middle portion of the screen, the blue boxes down the left side of the table are where your throttle position numbers go. With the software running in "OFFLINE" mode (not currently connected to the unit), it won't show the throttle position, as the measurements are stored in the actual E-Manage itself, not in the data file. But if it was "ONLINE", then you'd see numbers in those columns.
I still found the car running rich, even at idle. The ECU is definitely compensating for the increased air flow. It appears (as stated before) that the algorithm for the air/fuel mixture is incorrect from the factory.
I'm running at a 9% reduction (in air) so that the car leans out the gas... at idle.
Starting at 4200-5000, I'm up to a 12% reduction (in air) so that the car leans out the gas even more.
There's not a single range where I'm not reducing the air input to the ECU because of the over-compensating algorithm.
I'm scheduled to get back on the dyno soon. I'll be tuning the car for regular street driving, then for race driving.
Screen shots from the E-Manage are available at:
http://maxima.theowensfamily.com/images/e-manage.jpg
Please note that the values listed are not my final values, but they are just an idea of how the unit works.
In the middle portion of the screen, the blue boxes down the left side of the table are where your throttle position numbers go. With the software running in "OFFLINE" mode (not currently connected to the unit), it won't show the throttle position, as the measurements are stored in the actual E-Manage itself, not in the data file. But if it was "ONLINE", then you'd see numbers in those columns.
10-15-2003, 09:21 AM
#42
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
Originally Posted by Jeff92se
It would have been alot bette to get the wideband o2 sensor option. I would have shown if the a/f was getting rich/lean etc..
Unless Nissan had calibrated their injectors to function close to 80% duty on the stock hp ratings, I just don't see them going lean or overdriven. Maybe there's something in the ecu program that prevents big changes in the a/f ratios. But aren't the 3.5vqs in the Zs doing just fine w/ the sc and turbos?
Maybe there's something seriously wrong with the resonance tuning of the headers that make it drop at those rpm.
Unless Nissan had calibrated their injectors to function close to 80% duty on the stock hp ratings, I just don't see them going lean or overdriven. Maybe there's something in the ecu program that prevents big changes in the a/f ratios. But aren't the 3.5vqs in the Zs doing just fine w/ the sc and turbos?
Maybe there's something seriously wrong with the resonance tuning of the headers that make it drop at those rpm.
Sorry to hear about all this.
I'm with Jeff on this one. I'd find it very odd that Nissan would put injectors in the 3.5 VQ that are already close to maxed out. I've seen ATI Procharger's supercharged 350Z and talked to a couple techs that did the work and ATI is using the stock injectors. Only when they started pusing around 8psi did the injectors reach a critical level. A SC pushing 8psi is moving a ton more air than an NA 3.5 VQ ever could. I believe DAVEB has looked up part numbers and the 350Z injectors were the same as the Maxima's.
I think the problem lies in the tuning of the headers, possible conflicts with the relocated O2 sensors, and some sort of A/F issue under extreme load. Header tuning is a very complicated thing and you just can't whip out a pretty set and think it's going to perform. Good working headers scavage exhaust out of the heads and these headers may just be causing tubulence.
Looking at the dyno pull, you can kind of trace in a curve where the power nose-dived between 4400-5600rpms. Simply trace a positive curve that follows the beginning and ending trends for both HP and TQ. While not incredibly accurate, it should get you within 5-10hp/tq. From what I can tell, the curve in both HP and TQ would have peaked around 235hp and 235tq. Since he didn't show the scale, it's hard to know exactly, it looks like the TQ and HP scales aren't the same. Comparing the "assumed" curves on WillSE's Max vs Studman's header curves looks to show both cars have similiar curves. They both make different numbers, but they're dynoing on different machines. Either way, these headers aren't doing what they're suppose to and there is definately something wrong with WillSE's VQ with the huge loss in power.
The fact that his car is loosing so much power in the midrange means his car is significantly slower since that's where you spend all your time accelerating.
Dave
10-15-2003, 09:25 AM
#43
Not DAVEB the parts guy
Join Date: Aug 2000
Posts: 8,555
Originally Posted by Rafe
can be solved if you dyno tune . From what it seems like, you have worked on the air flow of things w/headers,intake ,exhaust, but no real work on fuel and other internals. An upgrade ECU would help too....remeber your stock ECU is still reading a stock set up. Wether or not you reset it or not, you have to have an ECU that is programmed to your mods.If it was that easy to just reset the ECU w/ mods, there would be no reason for performance companies to sell perfromace ECU's.
They would be out of business......
They would be out of business......
Nissan's ECU, like most OBD-II/III ecus, is able to "learn" changes in A/F ratios therefore the ECU can take advantage of most intake/exhaust work. Tuning ECUs for mods is more of an issue for late model turbo cars like WRXs.
Dave
10-15-2003, 09:54 AM
#44
Originally Posted by Dave B
The 97-03 ECUs can't be upgraded due to their design. The 95-96 and 04+ ECUs are upgradable.
Nissan's ECU, like most OBD-II/III ecus, is able to "learn" changes in A/F ratios therefore the ECU can take advantage of most intake/exhaust work. Tuning ECUs for mods is more of an issue for late model turbo cars like WRXs.
Dave
Nissan's ECU, like most OBD-II/III ecus, is able to "learn" changes in A/F ratios therefore the ECU can take advantage of most intake/exhaust work. Tuning ECUs for mods is more of an issue for late model turbo cars like WRXs.
Dave
They can be reprogrammed.
10-15-2003, 10:24 AM
#46
Supporting Maxima.org Member
Join Date: May 2002
Location: Atlanta
Posts: 1,815
Originally Posted by Jeff92se
Can Studman see off a OBD-II logger or e-manage if the ignition timing goes flat at 4xxx rpm?? I think that's the biggest mystery that needs to be solved.
I think logging the runs thru a obd2 scanner along with as much other data; elevation, temp, mods... will help us figure out what the ECU is doing.
Also do we know if the Z and the Max have the same fuel pump? Could this mod cause to big of a pressure drop for the pump? It doesn't seem likely knowing how far SR20 has pushed his with no2 but I thought I'd ask.
10-15-2003, 10:24 AM
#47
Jeff92se- Just a FYI regarding a previous post, I don't think the ECUs allow you to view Injector duty cycle via the OBD-II interface... only the Consult-II lets you view that... I think 
I hooked my Auterra OBD-II scantool up to Gooey's 2k3 and it didn't show injector duty cycle, neither does my 2k...
Now timing & O2S, that's a different story
I hooked my Auterra OBD-II scantool up to Gooey's 2k3 and it didn't show injector duty cycle, neither does my 2k...
Now timing & O2S, that's a different story
10-15-2003, 10:54 AM
#48
Timing would be even better. Cause I really think(at this point anyway) it's an ignition problem. Hell if he can even get a manual timing light signal off one of the signal wires to the coils, that might work. 3-gen VEs can steal a signal in the same way(direct ignition). The light should flash evertime it receives a signal. If the light gets erratic or just plain shuts off at 4xxx, you know something is goofy
Originally Posted by spirilis
Jeff92se- Just a FYI regarding a previous post, I don't think the ECUs allow you to view Injector duty cycle via the OBD-II interface... only the Consult-II lets you view that... I think
I hooked my Auterra OBD-II scantool up to Gooey's 2k3 and it didn't show injector duty cycle, neither does my 2k...
Now timing & O2S, that's a different story
I hooked my Auterra OBD-II scantool up to Gooey's 2k3 and it didn't show injector duty cycle, neither does my 2k...
Now timing & O2S, that's a different story
10-15-2003, 11:08 AM
#49
Maxima Pilot
Join Date: Oct 2001
Location: Beaverton, Oregon
Posts: 1,467
I hate to ask this but....hs anyone involved Brian Catts in the troubleshooting?
Surely he' has some vested interest in this because if this whole issue of headers adding power or not is'nt resolved to the Org's satisfaction, he's not going to sell many 3 liter or 3.5 liter headers either....
Surely he' has some vested interest in this because if this whole issue of headers adding power or not is'nt resolved to the Org's satisfaction, he's not going to sell many 3 liter or 3.5 liter headers either....
10-15-2003, 11:32 AM
#50
First, the VQ35 in the Maxima and the VQ35 in the 350z do NOT use the same injectors. The 350z and the 2K-2K1 VQ30 use the same injectors, but at different fuel pressure.
It's NOT the injectors running out of fuel. SR20DEN had Mardi send in his VQ35 Maxima injectors to be flow tested and they came back around 270cc at 3bar and 315cc@3.5bar. The VQ35s run at 3.5bar.
With 315cc injectors@80% duty cycle with a BSFC of .50, you're able to support 288hp.
With 315cc injectors@90% duty cycle with a BSFC of .50, you're able to support 324hp.
It's NOT the injectors running out of fuel. SR20DEN had Mardi send in his VQ35 Maxima injectors to be flow tested and they came back around 270cc at 3bar and 315cc@3.5bar. The VQ35s run at 3.5bar.
With 315cc injectors@80% duty cycle with a BSFC of .50, you're able to support 288hp.
With 315cc injectors@90% duty cycle with a BSFC of .50, you're able to support 324hp.
10-15-2003, 11:33 AM
#51
He's already shown dyno gains on both the VQ30 headers and VQ35 ypipe.
Originally Posted by Galo
I hate to ask this but....hs anyone involved Brian Catts in the troubleshooting?
Surely he' has some vested interest in this because if this whole issue of headers adding power or not is'nt resolved to the Org's satisfaction, he's not going to sell many 3 liter or 3.5 liter headers either....
Surely he' has some vested interest in this because if this whole issue of headers adding power or not is'nt resolved to the Org's satisfaction, he's not going to sell many 3 liter or 3.5 liter headers either....
10-15-2003, 01:13 PM
#52
Senior Member
Join Date: Feb 2003
Posts: 221
Originally Posted by IceY2K1
He's already shown dyno gains on both the VQ30 headers and VQ35 ypipe.
10-15-2003, 01:24 PM
#53
You've got to be kidding.
Stillen != Cattman
Cattman will stand behind his product 100% NO QUESTION. He can't run and hide behind other cars like Stillen. IF Cattman burned us he wouldn't have a business anymore. Plus, look at how he handled the "busted flex" problem on the ypipes.
You don't have ANYTHING to worry about.
Stillen != Cattman
Cattman will stand behind his product 100% NO QUESTION. He can't run and hide behind other cars like Stillen. IF Cattman burned us he wouldn't have a business anymore. Plus, look at how he handled the "busted flex" problem on the ypipes.
You don't have ANYTHING to worry about.
Originally Posted by amaxeatinvtecs
holy crap, that scares the jeepers out of me, my 3.0L headers from cattman should be here this friday, and i was really hoping for wills results to be positive. i know brian has showed gains, but didnt stillen do the same thing and look what has happened so far
10-15-2003, 01:55 PM
#54
Originally Posted by IceY2K1
First, the VQ35 in the Maxima and the VQ35 in the 350z do NOT use the same injectors. The 350z and the 2K-2K1 VQ30 use the same injectors, but at different fuel pressure.
It's NOT the injectors running out of fuel. SR20DEN had Mardi send in his VQ35 Maxima injectors to be flow tested and they came back around 270cc at 3bar and 315cc@3.5bar. The VQ35s run at 3.5bar.
With 315cc injectors@80% duty cycle with a BSFC of .50, you're able to support 288hp.
With 315cc injectors@90% duty cycle with a BSFC of .50, you're able to support 324hp.
It's NOT the injectors running out of fuel. SR20DEN had Mardi send in his VQ35 Maxima injectors to be flow tested and they came back around 270cc at 3bar and 315cc@3.5bar. The VQ35s run at 3.5bar.
With 315cc injectors@80% duty cycle with a BSFC of .50, you're able to support 288hp.
With 315cc injectors@90% duty cycle with a BSFC of .50, you're able to support 324hp.
10-15-2003, 03:00 PM
#55
Senior Member
Join Date: Jan 2002
Posts: 630
Originally Posted by Quicksilver
So then, in your opinion, is it the ECU that is causing the problem? If the engine can support at least 300 HP with the current injectors, then that leaves only the headers and ECU as the unknowns right now (I'm only basing this on the fact that nothing else was changed)...so that also means that Stillen HAD TO HAVE DISCOVERED THIS VERY SAME PROBLEM! Why, in their infinite wisdom, did they not inform the consumer of this?
10-15-2003, 03:05 PM
#56
Not sure....I was hoping studmans' was due to his eManage, but this shows it's not just him.
My 2-guesses are:
1)ECU is weird with compensating or the rear 02 sims. are not working how Stillen intended. Not sure how that's possible yet.
2)Stillens' design is bad and they didn't post the dyno for a reason.
My 2-guesses are:
1)ECU is weird with compensating or the rear 02 sims. are not working how Stillen intended. Not sure how that's possible yet.
2)Stillens' design is bad and they didn't post the dyno for a reason.
Originally Posted by Quicksilver
So then, in your opinion, is it the ECU that is causing the problem? If the engine can support at least 300 HP with the current injectors, then that leaves only the headers and ECU as the unknowns right now (I'm only basing this on the fact that nothing else was changed)...so that also means that Stillen HAD TO HAVE DISCOVERED THIS VERY SAME PROBLEM! Why, in their infinite wisdom, did they not inform the consumer of this?
10-15-2003, 03:21 PM
#57
Supporting Maxima.org Member
Join Date: May 2002
Location: Atlanta
Posts: 1,815
Will does have copy of a plot that has my run overlayed wih his. Our plots are almost identicle untill his take the dip at 44xx. Don't know if that sheds any light on this or not.
10-15-2003, 03:51 PM
#59
Senior Member
Join Date: Feb 2003
Posts: 221
Originally Posted by IceY2K1
You've got to be kidding.
Stillen != Cattman
Cattman will stand behind his product 100% NO QUESTION. He can't run and hide behind other cars like Stillen. IF Cattman burned us he wouldn't have a business anymore. Plus, look at how he handled the "busted flex" problem on the ypipes.
You don't have ANYTHING to worry about.
Stillen != Cattman
Cattman will stand behind his product 100% NO QUESTION. He can't run and hide behind other cars like Stillen. IF Cattman burned us he wouldn't have a business anymore. Plus, look at how he handled the "busted flex" problem on the ypipes.
You don't have ANYTHING to worry about.
10-15-2003, 03:56 PM
#60
Nope...FI or bust IMO.
Brian paid for all the ypipes to be fixed PLUS used an improved flex that's now standard issue.
He took a HUGE hit on that, but handled it very well IMO.
Brian paid for all the ypipes to be fixed PLUS used an improved flex that's now standard issue.
He took a HUGE hit on that, but handled it very well IMO.
Originally Posted by amaxeatinvtecs
hey ice, no headers to go with that five speed 3.0? or are u still waiting for some positive results........ i dont remember the flex section issue what happened brian just refunded everyone or something?
10-15-2003, 03:58 PM
#61
Donating Maxima.org Member
Join Date: May 2001
Location: Virginia
Posts: 925
Well we'll find out if Stillen is really full of crap or not here in about 2 weeks. By then my Stillen headers and Injen CAI will have be installed and I'll dyno them. Personally I think that there's something wrong with both Studman and Willse's cars. Both had issues with their cars and both in my opinion and the opinion of 2 highly respected mechanics I know have said it sounds like their cars have to much flow going out and not enough coming in. Example the high flow cat and b-pipe. Plus the ECU's have been toyed with and when Studman went to see about his car at Nissan it threw all kinds of codes. Also just last week Willse said that his car kept having problems. So in my opinion neither of these cars are going to be good bases for us to judge on weather these headers perform or not. Also everybody is entitled to their opinion on Stillen; so here's mine. Most of you guys wouldn't be able to do crap to your car's if weren't for Stillen to begin with. Unless there's something I don't know, isn't Stillen the one that really started it all for us Maxima owners. I'm sure that companies like Cattman, JWT and SouthwestAutoworks would agree that their bussinesses may would have not even exsisted if it wasn't for Stillen paving the way. I've got Stillen products on my car and despite what everybody else says I stand by them unless I become the 3rd person that gets a loss or no power gain from these headers, I'll continue to stand by their products. Sorry if I've offended any one with this post, but I had to get it off my chest.
10-15-2003, 07:01 PM
#62
That's not offensive in the least 1BADMAX...
It's just strange to me that there is no Stillen dyno publicly available, and no real information other than "claimed gains" and price...
It's very suspect. I think they may have rushed to get the header out first for the Maxima...
It's just strange to me that there is no Stillen dyno publicly available, and no real information other than "claimed gains" and price...
It's very suspect. I think they may have rushed to get the header out first for the Maxima...
10-15-2003, 07:40 PM
#63
Donating Maxima.org Member
Join Date: May 2001
Location: Virginia
Posts: 925
Originally Posted by Quicksilver
That's not offensive in the least 1BADMAX...
Originally Posted by Quicksilver
It's just strange to me that there is no Stillen dyno publicly available, and no real information other than "claimed gains" and price...
10-15-2003, 09:04 PM
#64
Originally Posted by Quicksilver
It's very suspect. I think they may have rushed to get the header out first for the Maxima...
How is a 6-8 month R&D a rush?
I am usually on the front line to bash Stealin for their business practices but I don't believe for one second that they didn't try to get this product done right.
10-15-2003, 09:20 PM
#65
Senior Member
Join Date: Dec 2001
Location: Charlotte, NC
Posts: 1,687
I am scheduled to re-tune on Saturday morning. I'll also be moving that day, so don't expect the results to be posted until sometime on Sunday. If I get a chance to post them earlier, I will.
The car is running 10920931x better now. It's finally 68° outside and the car pulled like crazy... it was nice shifting into 3rd gear around 80 MPH tonight.
More details later this weekend.
The car is running 10920931x better now. It's finally 68° outside and the car pulled like crazy... it was nice shifting into 3rd gear around 80 MPH tonight.
More details later this weekend.
10-15-2003, 11:05 PM
#66
Donating Maxima.org Member
Join Date: May 2001
Location: Virginia
Posts: 925
Originally Posted by studman
I am scheduled to re-tune on Saturday morning. I'll also be moving that day, so don't expect the results to be posted until sometime on Sunday. If I get a chance to post them earlier, I will.
The car is running 10920931x better now. It's finally 68° outside and the car pulled like crazy... it was nice shifting into 3rd gear around 80 MPH tonight.
More details later this weekend.
The car is running 10920931x better now. It's finally 68° outside and the car pulled like crazy... it was nice shifting into 3rd gear around 80 MPH tonight.
More details later this weekend.
10-16-2003, 06:47 AM
#67
Originally Posted by SR20DEN
Stealin rushed on something? Come on.
How is a 6-8 month R&D a rush?
I am usually on the front line to bash Stealin for their business practices but I don't believe for one second that they didn't try to get this product done right.
How is a 6-8 month R&D a rush?
I am usually on the front line to bash Stealin for their business practices but I don't believe for one second that they didn't try to get this product done right.
10-16-2003, 08:42 AM
#68
Originally Posted by Quicksilver
Yeah, but they made damn sure they were the first to offer 3.5L headers...that's my reference to rushing.
6-8times 
10-16-2003, 11:10 AM
#69
Senior Member
Thread Starter
Join Date: Jan 2001
Posts: 1,279
Originally Posted by HitManSE
They were the 1st to push to product, but they did have it listed for quite some time be4 they actually pushed it. We had to wait 30 days like... 6-8times
6-8times the headers have been coming out for like a year. stillen didnt rush them.
will
10-21-2003, 07:09 AM
#70
Senior Member
Join Date: Dec 2001
Location: Charlotte, NC
Posts: 1,687
My dyno results are:
218.9 HP and 225.9 TQ - +1 HP and -5 TQ
Here's a temporary image until I can scan in the actual printout.
218.9 HP and 225.9 TQ - +1 HP and -5 TQ
Here's a temporary image until I can scan in the actual printout.
10-21-2003, 07:45 AM
#71
Supporting Maxima.org Member
Join Date: May 2002
Location: Atlanta
Posts: 1,815
Have you called $tillen yet Studman?
10-21-2003, 08:48 AM
#73
Supporting Maxima.org Member
Join Date: Mar 2001
Posts: 860
I cant belive this
10-21-2003, 09:09 AM
#75
Senior Member
Join Date: Jul 2002
Posts: 616
that's messed up man 1000 bones for -8 tq... hope everything work out for you
10-21-2003, 07:55 PM
#78
Headers
I dont know why everyone is so down on these headers they are a little pricey but I have proven they give power...
http://forums.maxima.org/showthread.php?t=256334
http://forums.maxima.org/showthread.php?t=256334
10-21-2003, 08:50 PM
#79
Just a quick thought; I looked at pics of both the Stillen Headers and Cattman Headers and found one difference that stuck out, the size and location of the collectors. I remember Brian's original thread about the Cattman headers and that the collectors had to be made farther down the exhaust stream in order to make power, forfeiting the idea of reusing an aftermarket y-pipe. If by chance the Stillen headers have the same location and size collector as the stock, which it looks like they do, then I think the 20+whp gains are BS. Granted Juice made better time and speed in the 1/4, but if they had the same effect on eta and speed as gutting the precats. The following logic is not fool proof just ideas, 20+whp = .2 less eta, then gutting the precats was worth 20whp and the headers would be an increase of approx 40whp. 02+ guys it sounds like the y-pipe is the way to go. 00-01, I'll wait to SEE the dyno from Cattman first.
10-21-2003, 08:55 PM
#80
i just keep hoping there is a simple answer to why the headers dont make some nice power. I had headers on my old camry and I could tell it was more peppy,so I just cant understand why the VQ wouldnt react the same way, especially with the Altima headers from hotshot giving some serious power gains