I am out of town right now getting my 92 Maxima VQ35 Automatic tuned on a DynoJet. I am running a UTEC. I have Open Loop Fuel activated and have my rev limiter set to 7200 rpm at the moment. It works great on the street in 1st and 2nd gear. I have never topped out 3rd gear on the street or the track before.

But on the dyno, the stock rev limiter keeps engaging. We have done 15 or so runs in 3rd gear and we can't get it to rev any higher than 6600 rpm.

I found out I am making a ton of power at 6600rpm (271whp) and still climbing strong! I will definitely need to rev this engine out to probably at least 7500 rpm.

Does anybody have ANY ideas? TurboXS is closed on the weekends and we can't get a hold of anybody. I am hoping to be able to solve this problem by Sunday.

Thanks in advance.

 

Did you try 2nd on the dyno, just for the heck of it?

 

Not yet. But I want to.

 

It's your fuel map... it's got a nasty hole. That's why you're unloading in third. Unlengthen the injector pulse another millisecond, just tune the NOS timing, you'll run 9's

 

Nice power Aaron, even though I'm sure there's more in it when you get it to rev higher in 3rd. You could try calling some shops that are familiar with tuning the utec on a vq35 or try asking people on my350z. Good luck!

 

haha crusher said the same thing today!

I ran in 2nd gear today on the dyno. I had my extended limiter of 7200. Their tuner thinks there is a speed limiter of some sort. I agree. I don't think it can be anything else.

 

This shop specializes in the 350z. So, they know the UTEC.

I've never tried hitting the limiter in 3rd gear. But, it's possible I would be limited on the track as well. I will know more once I do more diagnosing.

 

is this on an auto ECU? if so, are you hitting the limiter at 130mph? The vq35 auto ECU has a limiter at 130mph or so, where as the 6spd has a limiter at like 148mph

 

^if that's the case ask to see if technosquare could remove the speed limiter. Hopefully they have your ecu code.

 

AHH i KNEW IT



i just dont know how to fix it HAHAHa dam

 

I was under the assumption that you can remove the speed limiter completely with the UTEC. Especially if you're using a 3.5 ecu. Someone correct me if I'm wrong here.

 

Thanks. After doing a bit more research, I see several people are talking about a 130-132 mph speed limiter on only certain 2002-2003 Maxima ECUs. The ECU I'm using is out of an 02 Maxima GLE.

I am being limited at 125 mph according to my dyno sheets, which is basically the same thing considering the speedometer is showing 128mph exactly.

I have a 6spd ECU already in order to get my cruise control working. I just have to install it. That should allow a much higher speed limiter.

The UTEC doesn't allow you to change the speed limiter.

 

Damn I wish you could have gotten ahold of me, moms I35 rode (re: shifted, drove, etc) fine with no vss for several months, only the lack of speedo, & of course a cel, was noticed.


WOW, congrats, and as to be expected you def. owe me a steak + beer, though I didn't see it happening @ 6.5k!!!!!!

 

Thanks. That's good to know that you can get rid of the VSS signal wire and remove the speed limiter. If I ever run into the speed limiter on my 6spd ECU, then I'll keep that in mind. But, if this ECU does have a speed limiter, it will be at 149, which is good until I start seeing mid 10s @ 130mph (22" slicks change final drive).

I did 271whp with SAE. Uncorrected, I made 277. STD, I made 278.

 

the limit on the 5.5 auto ECU is about 135... however as deckdout said, the UTEC should be able to get rid of such limiter... should look something like dandy's graph where it has a major dip for probebly 100rpm then back to regular pass the stock limiter... i hear 7500rpm, any HR equipments with this motor, it would be nice to see a motor with HR upgrades and dyno #

 

the utec doesnt get rid of the stock speed limiter, and dandy was using an EU

 

The UTEC instructions make no mention of being able to change the speed limiter. I certainly haven't seen the option while going through the parameters. If you know how, please let me know. It may come in handy for me one day.

My speed limiter is at exactly 128mph according to my speedometer. Every speedometer is different though. 128-135mph, same difference.

I have already swapped in a 6spd ECU and it's working great now.

 

If it's not the car, it may be a dynamometer speed limit. You didn't mention the dyno type, but some have programmable speed limits.

 

I've already solved my issue. My 02 Maxima GLE AT ECM had an 128mph speed limiter on it. That is exactly why I was limited on the dyno. This DynoJet doesn't have a speed limiter on it that would effect what I'm doing. They've gone as fast at 190mph on that machine and it can handle a lot more speed.

I now have a 6spd ECM install, which either doesn't have a speed limiter at all or has a 149mph speed limiter. Either are fine for the type of racing I'm doing, 1/4 mile.