I have my car at the shop to get it tuned and they are having a problem. I wanted to get some feedback.

It seems that my car is intermittently going lean on the Dyno from run to run. My shop tracked down the problem and the fuel pump is not turning on. They checked all of the wiring, etc and even installed a manual switch to turn the fuel pump on and off and it is working. Apparently the split second box is not always sending a signal to the fuel pump to turn on. They have loaded the stock map and are still having the problem.

The shop has talked to the spilt-second who make the box and got some infromation about updating the aux fuel pump in the R4 software and I wanted to understand what the problem is so I have a few questions.

Has anybody else had any of these problems with the spilt-second box?

How do the settings in the R4 Software to control the aux fuel pump work? What are the stock settings? Do the settings change if I am tuning the car for more HP?

Thanks ahead of time for any answers to any of the questions above.

The shop has spent 2.5 hours on the dyno and about $125 dollars on researching the issue. They charge $150 an hour for dyno tuning. They are putting back on the dyno today probably for another 2 hours.

I want to understand if this is something they should have been aware of. That is why they get $150 an hour, right? If it turns out to be these settings shouldn't they have known that? If they put it back on for another 2 hours it will cost me $425 for them to change some settings. I expected to pay for 2-3 hours of dyno tuning, however I did not expect for them to not know about these settings. They have tuned multiple vortech 350z/G35. Paying the extra money does not sit well with me. Any ideas on how I should approach this?

Jeremy

 

[QUOTE=LeMans350z]I have my car at the shop to get it tuned and they are having a problem. I wanted to get some feedback.

It seems that my car is intermittently going lean on the Dyno from run to run. My shop tracked down the problem and the fuel pump is not turning on. They checked all of the wiring, etc and even installed a manual switch to turn the fuel pump on and off and it is working. Apparently the split second box is not always sending a signal to the fuel pump to turn on. They have loaded the stock map and are still having the problem.

The shop has talked to the spilt-second who make the box and got some infromation about updating the aux fuel pump in the R4 software and I wanted to understand what the problem is so I have a few questions.

Has anybody else had any of these problems with the spilt-second box?

are the stock settings? Do the settings change if I am tuning the car for more HP?

Thanks ahead of time for any answers to any of the questions above.

The shop has spent 2.5 hours on the dyno and about $125 dollars on researching the issue. They charge $150 an hour for dyno tuning. They are putting back on the dyno today probably for another 2 hours.

I want to understand if this is something they should have been aware of. That is why they get $150 an hour, right? If it turns out to be these settings shouldn't they have known that? If they put it back on for another 2 hours it will cost me $425 for them to change some settings. I expected to pay for 2-3 hours of dyno tuning, however I did not expect for them to not know about these settings. They have tuned multiple vortech 350z/G35. Paying the extra money does not sit well with me. Any ideas on how I should approach this?

Jeremy[/QUOTE

A discussion I had with Vortech on what turns on the aux fuel pump he indicated it was boost pressure at about .75 psi. The ss box has a press line fed into it which is sensing manifold. The ss sends a signal (voltage) to turn it on. The FMU has a pressure port that comes off the manifold also and when the press reaches about the same .75 it allows fuel flow thru the aux fuel pump.

Might want to have all the pressure lines rechecked for leaks.. Good luck

 

Whenever you create a new R4 file you must set the AUX pump settings, even if you upload your existing SS Box values into the new file! If you forget to set those values, the defaults are NOT set correctly. I don't have the R4 software handy, but there's a dialog box where you set when the AUX pump should come on. You can set it to come on based on RPM and/or boost. There's no reason the pump should come on unless you're in boost, so I personally would set it to something like 2000 rpms AND 1 psi.

Keep in mind that changing this value will affect your entire fuel map, so unless you have your own laptop (which I recommend) you're possibly going to pay $$ to have it reworked.

Bottom line: if the shop claimed to be R4 experts but did set the AUX turn on values or did not know they needed to do so then they misrepresented themselves.

--Steve

 

Here is the document that I referenced. It is something that I threw together from various posts about a year ago. I hope that it is accurate.

VortechSSTuning.doc

 

once you open the R4 , Click on Options....then output settings.....output B....should read ......over rpm and pressure......over rpm...should read 3000......over pressure...should read....0 to 2 psi .

 

Those didn't work for me. We had 3000, 2, and over injec at 10

 

Also, on the AUX Pump there are two wires (positive and ground). It is very easy to not hook them up correctly. The pump is marked. Your dyno looks exactly like mine when I did my first pull. Didn't find the problem until we hooked up a pressure gauge on the AUX pump.

 

You may want to invest in a fuel pressure gauge. It's an early warning system for fuel pump problems and will show you precisely when the aux pump turns on and how steeply the pressure climbs as boost winds up. I set up my SS box to turn on the aux pump at 2 lbs. At that point, there's an abrupt jump in fuel pressure from 52 to 60 psi. At 8 lbs, my fuel pressure gauge reads about 100.

 

Thanks for the feedback everyone.

The put the car on the dyno last night. I hope to get it back today and I will let you know what I find out.

Jeremy

 

Well it seems updating the settings has worked and they were able to tune the car. They tuned it to 401 at the rear wheels and set the air fuel to be 10.8 over 6000 RPM. Nice and safe and plenty fast. I do not remember the torque however I will post the dynos tonight once i get the car back.

Jeremy

 

nice numbers Jeremy, glad to hear they got you squared away!

 

Thanks for the help everyone...

Here is the dyno:

 

Your chart is almost an overlay of mine.Where they differ is down low Below 3500rpm. Your Tq. #'s are slightly higher but your A/F is a little leaner here which would account for the delta..

 

Cool. I have the same headers, crawford cats and stillen exhaust with the stock plenum. I have the new Kinetix intake on order. So I take it you have your car runing rich at the top end as well for safety?

So tell me about the AAM ECU Reflash. I have not reflashed my car yet is this something I should do? Do you have to reflash after each mod?

Thanks!

 

I'm glad that worked for you. Hopefully the dyno shop was willing to compensate you somewhat (assuming they claimed to have R4 expertise). Regardless, nice numbers--congrats!

--Steve

 

I found myself bumping against thr rev limiter too many times (light fly).The flash raises it to 7100rpm.(+500rpm) It will raise the speedoo limit (if you so desire) as well as allowing the throttle to open fully.. Believe ECU limits it to 80%.

The stock maps can also be modified..I get it dyno tuned after each mod..Next is the 3.12 pulley which I received yesterday..

 

Any ideas at what HP you are going to stop and build the motor? I have the crank angle sensor however any number of factors could affect the outcome and lead to a blown motor. I am thinking after the intake I will need to stop adding power and look at the motor. If the intake gives me 20-30 HP I would be happy with the investment however the higher I go in the 400HP range the more nervous I get.

80% that is not good. Reflash sounds interesting. How much is the reflash? How long does it take? How many companies do this service?

Thanks for the info!!

Jeremy

 

Thanks Steve!

They charged me what they worked on the car and explained why that was. I am not going to let it bother me.

They aren't sure that the fuel pump thing is resolved and I am keeping a close eye on the A/F numbers when I drive. So far so good.

Jeremy

 

I am not as concerned as much about Hp as I am with Tq. Tq is what stresses an engine.. The TT's develop a lot of Tq. early and coupled with either a bad tune and or less than desirable engine mg'mt I believe accounts for the several that have blown..The S/C's on the other hand develop less tq and gradually slope up.

As far as the reflash I believe only 2 Co's have the capability today. AAM (CHECK THERE WEB) they are sponsor and the other is Technosquare but you have to send the ecu to them.My intent in going F.I. was to have a fast car and I am quite comfortable with it as is..The 3.12 will add about 1psi and shouldn't cause any significant degradation to engine..

 

Any ideas on what the settings were?