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Took car to dyno today, have fuel issues
So, after having my FM II kit installed for almost a year, I finally took it to a dyno tuner (Church's Automotive in Long Beach) today. The guys were very thorough and tuned the car for a consistent AFR around 11.8 without the EBC connected. The car was developing about 6psi at 3200 rpm then slowly increasing to right around 9psi at redline. The tuner commented about how much fuel he had to add above 5500 rpm to prevent it from going lean.
When we were satisfied with that, we started tuning the EBC. Long story short, we were finally able to get the same range under control (max boost 14psi), but he said the 550cc injectors are running about 95% duty cycle. He said I might have some sort of fuel issue, and I might consider upgrading the fuel pump. All of the posts here and on M.net talk about people upgrading the pumps, but they only refer to NAs and I have a 99. Any suggestions on what I can test or how I can confirm this is the problem? Let me know what information you need and I can try to post it. As soon as I can find the cable for my digital camera, I will post some videos. |
it doesnt help that we have shit for gasoline here in cali, so you end up having to run richer than most other people to stay safe ftl...
do you have a fuel pressure gauge? |
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Some pics and the overall results :)
http://img379.imageshack.us/img379/3...g016yj2.th.jpg http://img522.imageshack.us/img522/7...g015sf6.th.jpg http://img522.imageshack.us/img522/7...g003aa1.th.jpg 35000 cfm fan, simulates 80mph driving! http://img142.imageshack.us/img142/6...g005qy2.th.jpg |
Originally Posted by 18psi
(Post 315913)
it doesnt help that we have shit for gasoline here in cali, so you end up having to run richer than most other people to stay safe ftl...
do you have a fuel pressure gauge? |
Hrm... can't seem to figure out how to embed the youtube video. Make sure you watch it on high quality or you can't see anything.
http://www.youtube.com/watch?v=7x6PUgVT3aI |
Do you mind me being nosey and asking how much it cost to have it tuned at that shop? I'm thinking of getting mine done there too(after I deal with my state referee ticket:mad:).
Feel free to PM me if u like. |
sent you PM
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With nothing in your signature, I have to assume that's a Hydra fuel table and a 2560? HINT HINT NOOB!
Dynapack compares similarly to a Dynojet, but I just did some searching and found sveral places that claim Churchs machine reads a little on the high side. 250whp@14psi on a '99 is about right... maybe a little low, but that's even weirder if Church's typically reads high. In any case, you should be nowhere near 95% duty cycle. 550's and the stock fuel pump should be good for a tick over 300whp. You may indeed have a fuel issue. An upgrade for the stock fuel pump is the Walbro190lph, no need for the HPmodel on a standalone car. A new fuel filter is good insurance too. I don't know how you'd check the health of the fuel pump on a returnless car, so it might be a good idea to spend the $100 for a new pump and filter. Pumps and filters at your local KragAutoPepVance. And make it easy on us to give advice... fill out your signature please. I'm really interested to know what exhaust you're running if I got the rest of it right. |
Sam, you are right on with the parts list. (goes to fill out sig...)
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test of new sig
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Can we see some AFRs from (and I hope you did) the datalog you took for the run? 95% duty is way high.
Example: at 7000 rpm and 9.5 psi (250 rwhp) I'm at 68% on my 550s. That's at 12.2 AFR. |
It's possible if he wasn't maintain fuel pressure, yet dropping it, he could be hitting those high DC% numbers. Aren't '99s notorious for dropping below 60psi?
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+1 for all the above. Your problems are likely a relatively cheap and easy fix. Walbro 190 pump and a new filter just in case. The pump is about a 15 minute fix your very 1st time. Just follow the directions in Mnet's garage. It's worth doing without a 2nd thought.
Log some full throttle pulls and see where the duty cycle is after the new pump and filter. |
will do. I didn't do a data log on the dyno because I didn't have my laptop connected. I might get around to doing it if I can break away from the house a little while later today. If nothing else, I think I am going to look for a new pump and filter. For the pump, can I get the same one that is rated for the NA miatas? That lightning motorsports place only has the NAs listed and Walbro doesn't show that they carry a version for the NBs.
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Originally Posted by y8s
(Post 316017)
Can we see some AFRs from (and I hope you did) the datalog you took for the run? 95% duty is way high.
Example: at 7000 rpm and 9.5 psi (250 rwhp) I'm at 68% on my 550s. That's at 12.2 AFR. |
He has a bigger turbo - 2871, IIRC. Much more flow at lower boost levels.
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Originally Posted by boileralum
(Post 316090)
He has a bigger turbo - 2871, IIRC. Much more flow at lower boost levels.
The Garrett GT25, p/n 705330-0002. aka the GT2876R. Compressor: 0.70 A/R, 48 trim, TO4S (2.09/3.00 dia), 44 lbs flow. Turbine: .86 A/R, 76 trim, NS111 (1.85/2.12 dia). (I have since swapped in the -0001's .64 A/R turbine housing) |
Originally Posted by cueball1
(Post 316056)
+1 for all the above. Your problems are likely a relatively cheap and easy fix. Walbro 190 pump and a new filter just in case. The pump is about a 15 minute fix your very 1st time. Just follow the directions in Mnet's garage. It's worth doing without a 2nd thought.
Log some full throttle pulls and see where the duty cycle is after the new pump and filter. |
Originally Posted by elesjuan
(Post 316095)
I believe he has a T04 compressor none the less.. from his DIY page in sig:
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Originally Posted by Braineack
(Post 316097)
search some of POPSTOY's posts on m.net, he went through a few different pumps until he found one that didn't drop pressure.
On another note, if I am already having issues like this, should I start looking into a dual feed fuel rail? I think there are some DIY methods posted here, I just don't want to mess with stuff unless I need to. |
Does anyone have a recommendation to hook up a fuel pressure gauge to a returnless (03) system? The hard lines run to the FPR which then has a quick-release. Do you just cut the soft line that goes to the rail and T in with the gauge? I'd think you'd need a new quick release line after that.
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when I put in my dual feed rail, I just pulled the quick disconnect fuel lines out (get the tool) and put hoses and clamps on the hard lines. they've got the equivalent of a bead roll on them already.
oh and get a dual feed rail so it's worth your while. :) |
^I agree with Y8s that a DFFR is a good idea, but it has nothing to do with your 95*DC problem.
Your next step is a new fuel pump and filter... then do some datalogging. |
thanks guys. Any suggestions for a good place to buy said fuel pump? I read through some of POPSTOY's threads on M.net and he seems to favor the 255lph Walbro pump. Though I am not sure if that will give me issues with idle tuning or not. Since I have the Hydra, I assume I can meter the fuel enough to adequately control the idle, but I want to make sure. So should I get the 190 or the 255?
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Though I am not sure if that will give me issues with idle tuning or not. |
Lightining motorsports for the pump. Got my 190HP from them and they were good to deal with.
http://www.lightningmotorsports.com/index1.htm |
Originally Posted by boileralum
(Post 316090)
He has a bigger turbo - 2871, IIRC. Much more flow at lower boost levels.
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Originally Posted by jayc72
(Post 316469)
Lightining motorsports for the pump. Got my 190HP from them and they were good to deal with.
http://www.lightningmotorsports.com/index1.htm http://shopping.lightningmotorsports..._Kit-p-89.html Please confirm that I have the right one (they don't have one for 99+). Also, the 255 is only $10 more than the 190. I am leaning toward the 255 unless someone can come up with a good reason that I shouldn't. |
The 190 is all you need. When I was researching the same stuff the general consensus was the 190. It doesn't move as much volume but it pumps at a higher PSI if I remember right.
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There are a few draw backs to a non-return fuel system, that need to be taken into account, the biggest of which is the inability of adjusting fuel pressure. It is fact, not opinion, that only the walbro 255 lph-hp is capable of maintaining 70 psi of fuel pressure above 5500 rpm with my engine producing 159.9 rwhp at 6850 rpm. It is also fact, not opinion, that with a walbro 190 lph-hp that my fuel pressure fell off to less than 50 psi at about 5500 rpm, and despite safe tuning was only capable of 145 rwhp, on the same dyno. Because you already have a return system, that allows use of a afpr, and the fact that the 99 head makes more power with the better atomization of higher fuel pressure, only being possible with the walbro 255 lph-hp, and an afpr, other than heat being transferred to the fuel, and excessive fuel flow being returned, I see no other detriment to using the big walbro, well maybe noise too. Oh, I used a fluidyne afpr, with a vacuum port, adjusting the fuel pressure to 60 at idle with full vacuum, at wot and no vacuum, it increases fuel pressure to 70 psi, a safe limit for injector reliability. Bob |
I have the 255 HP in my car and the 99+ cars do need a pigtail adapter to make the Walbro work. The place below sells the pumps, but sold me the pigtail seperately. Hope this helps!
http://www.aztpi.com/product.php?pro...7&cat=0&page=1 |
OK so I'm an idiot talking out my ass. Like everyone didn't know that already. Didn't see the fact he had a 99. Duh...
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Thanks for the info guys. I am going to contact that vendor and see how much they will charge me for the connector.
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I thought injector-rehab who used to be a vendor sold the pigtails and Walbros. I just cut off the eyehole connectors on the pump wire and put on spade connectors and used an NA fuel pump.
Frank |
Originally Posted by fmowry
(Post 317174)
I thought injector-rehab who used to be a vendor sold the pigtails and Walbros. I just cut off the eyehole connectors on the pump wire and put on spade connectors and used an NA fuel pump.
Frank BTW thought I'd mention that when I went to the dyno (York Automotive in Mt. Airy) I had a problem with going lean at high RPM irregardless of trying to add fuel in the Hydra map which is why I'm going to be replacing my pump and filter too. |
Originally Posted by faeflora
(Post 317186)
Did you just solder/shrink them on? If that's all that's involved I won't worry about a pigtail.
BTW thought I'd mention that when I went to the dyno (York Automotive in Mt. Airy) I had a problem with going lean at high RPM irregardless of trying to add fuel in the Hydra map which is why I'm going to be replacing my pump and filter too. Frank |
Well I ordered that pigtail from the link above. $8 plus shipping is acceptable for me not having my personal soldering and shrink tubing involved in my fuel tank... I am also going to order the 255 walbro today. Let's hope this fixes all of my fuel problems.
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Pump should be here Wednesday!
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dip me in pig shit for asking
and plugging into this thread but I was always told or seen it on vendor pages not to run over 12 psi on stock internals on a NB, especially 2001 and up.
I would much prefer 14 psi -vs- 12 psi... so ..? don't really know what my question is.. but am I in the 'danger zone" if I up my boost to 14 psi? and tuned good? Buck |
well the strange thing is the printout says I got up to almost 14 psi, but the video I posted of the same run only shows me getting a little over 12 psi. Strange. As for the psi range, I also heard that running over 12 is iffy with a stock NB engine. 2001 and up is worse because they have a higher compression ratio than the 99/00.
After driving around for a week with the new setup, I CAN'T WAIT for the new fuel pump. Every time I get into boost, I can watch my fuel gauge go down. Feels like when we used to have the SS Camaro... It is dumping in SO much fuel... Oh well, at least it is safe but I will have to pay to have it retuned when I put in the new fuel pump :( |
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Went back to the dyno today to have him do some more tuning. I REALLY need to get around to installing this fuel pump... According to the log, I am hitting 65-100% duty cycle to keep the AFR under control. So, I am going to install the new pump this weekend, and hopefully it will allow the injectors to do what they need to do.
The only other thing I see is that the boost is getting a LOT higher than I have it set for. The realtime display on my laptop shows it just touching 14psi then settling down to 12. According to this log, I am getting 16psi :eek: Can you see any other issues I need to address? |
i saw the same thing on the dyno. the Dynojet software was reading exactly 1psi above what I was logging.
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This is a log from when I was driving home, not on the dyno. Is there a good way to get a power estimate from megalog viewer? I haven't played with it that much to know how to get calculated fields from a log file.
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one more question: if I changed out the rear differential from a 4.3 to a 3.9, will the vehicle speed sensor be off? I haven't changed the speedo gear yet, so I assume it will be. I ask because I am trying to get an estimate of 0-60 times and I think I have to back calculate for a different indicated speed.
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