It finally happened..

[treekiller]

The "Jeffproof" sentra finally shit the bed.

I'd like to list accomplishments
37 track days, most with 2 drivers. on 13 tracks
25 autocross events
16 Rally crosses
1800 Rally miles (pre-runs and events)
6 sets of front brake pads 3 rear
7 sets of tires

this alone is more wear then most cars get in a lifetime.. and what broke? did it blow a motor, toss up it's tranny.. NOPE.. a pedal position sensor took this beast down. that's right... a simple electronic part... I've distroyed several cars in the mission of distructive testing and NEVER have seen a car just keep on chugging like this,

I want to publicly thank Charles for helping me get home, and giving me the pleasure of driving his 240 home.. which except for the JDM lights being about as bright as candles in Bell jars, and focused on the ditch on the right side of the road. made me understand why people love those cars. easy to drive, responsive, and all in all a nice ride. but he used his beater truck and trailer to take the car back to my house which is a HUGE help for me getting it fixed.

hopefully it's only a sensor and I'll be back terrorizing your local streets. I said for YEARS that only a BMW could handle my level of abuse. but this car has surpassed ANY BMW I've owned..

and even Loren in his (T.O.Y.O.T.A) Tiresome Overated Yawnmobile On Thin Aluminimum.. had some issues this weekend. so I feel pretty good.. I look forward to tearing up the track soon.. tome to surf ebay for some sensors.

Jeff

[Loren]

Glad you got the car home without too much fuss.

I'm still amazed at the lack of grace Toyota coded into the ECU for a detected high-rpm misfire on this car. It drops the engine into limp mode with almost no power and keeps it there until you restart it! Replacing the OE iridium uber-plugs with a fresh set of NGK V-powers seems to have cured the problem.

[Mars_302]

man ignition problems on a new Toyota already?

[Goumba]

I killed my first qr25 at 72k. It only had about 50 autocross events, about a dozen rallycross, and one day at CMP. A rock to the radiator disabled the car on the way to last months rallycross.

[treekiller]

I'm still amazed at the lack of grace Toyota coded into the ECU for a detected high-rpm misfire on this car. It drops the engine into limp mode with almost no power and keeps it there until you restart it! Replacing the OE iridium uber-plugs with a fresh set of NGK V-powers seems to have cured the problem.

I might see this logic if the engine was tuned to within an inch of it's life but it's really not 100hp from 1.5 litres in 2007 is not really THAT agressive the old Swift did 100hp from 1.3 litre and that was with 1980's flapper door airflow based injection. but on the other hand I see some of the logic here since the car/engine was never intended for that purpose. it's why "normal" people love toyota's they have a "Prime Directive" to save the host machine. that's why they last so long. of course I was able to kill my last toyota in 4 months, and the person who took it from me killed the replacement engine in 6 months. both from oil filter failures. WEIRD!

[Loren]

man ignition problems on a new Toyota already?

It's not unheard of for any new car to have a random coil pack problem... if that was the problem. (and until I've beat the snot out of the rev limiter at a few autocrosses, I'm not ready to say for sure that new plugs were the definite fix)

And a bad plug at almost 20k miles with the kind of abuse this car has seen isn't such a big deal, either. All it was doing is misfiring at very high RPM, the kind of RPM that most normal people never take a Yaris to. The problem (for me) was that the ECU didn't handle it gracefully. But, Jeff's right... definitely the safest way to handle it from the "save the engine" perspective.

Got your Nissan fixed yet, Jeff?

[treekiller]

Got your Nissan fixed yet, Jeff?


nahh part is 4 days out. I had to go to the dealer and PRE-pay for the part. (apparently courtsey nissan is the only companay in the world that can't take a credit card over the phone) so it was a bit of a pain to get there... but the good thing is it's only $50 with my Nissan Motorsports discount.

we will see when it comes in.

[Goumba]

Nissan motorsports discount!?! That could save me a bagillion dollars about now. How do you get one? I've got some stuff that needs replacement. My car is still wounded from my treekiller incident.

[Loren]

4 Days??? Geez, even the backwoods Sebring Toyota dealer could get it in 2 days. WTF?

$50 is good, though... hope that fixes it.

[Spin Out]

"they have a "Prime Directive" to save the host machine."
Thanks for that line Jeff, Very funny.


On an unrelated subject, I found out that the Fiero "Rev Limiter" turns off the fuel injectors until you drop 2,000 rpms. If my MX-5 hits the rev limiter, at least it keeps running. Hit the rev limiter in the Pontiac, and that run is blown.

[Charles]

I want to publicly thank Charles for helping me get home, and giving me the pleasure of driving his 240 home.. which except for the JDM lights being about as bright as candles in Bell jars, and focused on the ditch on the right side of the road. made me understand why people love those cars. easy to drive, responsive, and all in all a nice ride. but he used his beater truck and trailer to take the car back to my house which is a HUGE help for me getting it fixed.


No problem, I will look you up for a nice discount when I've decided on a new strut/spring combo for the 240;)

Thanks to Loren and Jeff for getting the event moved over to Sebring:bigthumb:

I elected only to run Sunday to uncover any kinks in the car before shelling out the cash for 2 days and finding out I had reliability issues.

Turns out this was the right choice.........

On my last 2 sessions I started to overheat the car around 10-15mins in.
If I cruised the course for 1/2 lap or so without much boost and no more than 70mph the temp would immediately drop back down.

Same scenario both times yet the car didn't use a drop of coolant or oil all day.

Good news is the SR and car are obviously fine as Jeff drove it ~90 miles back to my place w/o a hiccup

I'm pretty confident the front aero is to blame, I have 4-5" gaps on either side of the radiator. At high speed the air was probably taking the path of least resistance AROUND the radiator. Combine that with lots of time under full boost = overheat city. Air also needs to pass through the intercooler first.

I didn't bother removing the JDM 115mph speed limiter before the event and still had the cooling issue.


The game plan is larger radiator, flush system, and fab up some panels to block-off escape routes for the airflow across the radiator.

[longfellow2]

I didn't bother removing the JDM 115mph speed limiter before the event and still had the cooling issue.


Just unplug the 4th/5th gear sensors to remove the Speed limiter. When your done at the track plug them back in. Or make a neat little kill switch so you can just turn it off from the inside.

Nissans are neat little cars. My 240sx has 202k on the motor/chassis and I drove 4 hours up to deals gap, drove the road all day the drove back 4 hours away to where I was staying that weekend and the car never missed a beat!

[Mars_302]

better knock on wood

[treekiller]

yea kock on wood. apparently after tracking the entire wiring harness and replacing the demand pedal assembly I still have an issue... so I'm looking now at ECU... at this point I'm ready to ditch the fly by wire and install my standalone.. that has been sitting in my storage unit for a year...

[Charles]

Just unplug the 4th/5th gear sensors to remove the Speed limiter. When your done at the track plug them back in. Or make a neat little kill switch so you can just turn it off from the inside.



Whenever I unplug them I have no reason to ever plug them back in. 99% sure they serve no purpose other than to kill the fun @ 115mph. Nissan got pretty creative with the limiter on these things back in the day.
Not only does the ECU look at the speed sensor but if it sees over X,XXXrpm in 4th or 5th gear that would equate to more than 115mph that will also stop the show.

My homework tells me after I unplug both sensors I will also need to cut the wire going from the speedometer to the ECU.

Apparently the wiring goes speed sensor -----> gauge cluster ------> ECU
so I can cut the wire and the speedo will still work, up to the 180kph (~110mph) it registers anyway.

[Mars_302]

I know theres a proper way around it and a write up to convert the kph cluster to mean mph, just search on some of the more tech nissan sites

[longfellow2]

Whenever I unplug them I have no reason to ever plug them back in. 99% sure they serve no purpose other than to kill the fun @ 115mph. Nissan got pretty creative with the limiter on these things back in the day.
Not only does the ECU look at the speed sensor but if it sees over X,XXXrpm in 4th or 5th gear that would equate to more than 115mph that will also stop the show.

My homework tells me after I unplug both sensors I will also need to cut the wire going from the speedometer to the ECU.

Apparently the wiring goes speed sensor -----> gauge cluster ------> ECU
so I can cut the wire and the speedo will still work, up to the 180kph (~110mph) it registers anyway.

The usdm 240sx has the same thing. IIRC you dont have to do anything but disconect the two gear position sensors. If the ECU dosnt know your in 4th or 5th gear there is nothing stoping you from going faster. The only thing that holds it back is that with the 5th gear sensor still intact it knows that in that gear at 5xxxrpm = 115mph so its time to slow down. Im fairly sure its not actually based of the speed sensor at all.

On the USDM S13 you could just swap in an auto ecu and bypass the entire thing since the automatic cars never had a speed limiter. I think that same thing applies to Retop Sr20's

[Chin]

Guys... really its this simple take off your kick panel pssenger side, cut Yellow with green wire from ECU. Go over 115mph...DONE, no unpluging sensors replugging / making switch, no tricking ECU just cut the wire enjoy working speedo go fast. Oh and 240's are fun till you get through 10 corners and the brakes go to shit....

[Charles]

Thinking about signing up for NASA @ Sebring for Sun Oct 12th... anyone else going?

[treekiller]

I can now that my car is Fully functional again.. Dead shorts buried in the wiring harness SUCK!!! but I need to save up for a new lift...