I took my car to dyno today and this is my first time dyno. Kevn and maxboost00 (nice meeting you guys) were there. I was shocked at my first 3 run...

the A/F ratio went up really really fast. It was 14:1 @ 3800 and it went up to >18:1 at 4800

Kevin quickly i.d. the problem. The aux fuel pump was not turned on because a wire was loose. Finally we brought it back and run it again. It was fine and max whp is 273.5 and torqued is 238.1. Now she's running super rich.


I dunno since when the wire was loose. But I want to know if this put any damage on the engine. Kevin told me that I wont be able to reach this whp if the internal is damage. My oil report seems ok, metal and coolant readings were within the limit. Havent checked my spark plug nor did a compression test.

In addition.....I always watch my EGT closely, I let go off the pedal at 800c all the time. (highest that I have went was 870) I go WOT almost daily for few second and rarely go above 800.



please advise

oh....and my ECU never never received any code. never heard any detonation/pinging. hmmmmmm......what's going on.







thx all

 

You should be fine then. Only issue if need to tune out the car now with an SAFC or a Fields AFC. Get that reading close to 12.5:1 or a tad lower and you should be over 300whp for sure.

Dixit

 

If you want to confirm that no damage was done, do a compression test. Kragen has a kit for ~$30 I believe.

Good dyno! Time for a Cartech or AFC and 2.5" cat-back!!!

 

my dyno, 2k auto, (v2, 2.87, 3rd gear 10psi, stillen y, stock cat and cat-back)

dyno graph


thx dixit! I hope there was no harm done to the engine.

my a/f now is below 10:1 after 4800. So I have a lot of space for tuning. Kevin suggested to change my fmu to Cartech adjustable fmu. Also getting an S-AFC is a good idea. I saw Kevin fine tuned maxboost00's car to a nice 12.5:1 ratio. He started with an A/F similar to mine.

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Oh Kevin : thousands of thanks to you! thank you for staying late with us and helping us out! thank you thank you thank you!


and maxboost00 : thanks for helping me out too.

 

gotcha! glad that I kept an eye on my EGT. I will do compression test soon.


I will get either one of them after the tax season is over. Uncle Sam is mean to me this year.

 

Hahha that chart is amazing, i mean the a/f drops off and never comes back, ****. You might be really hurting in the wallet. I think im the same way, I did 400 on one tank on a 600mile drive, then when I started getting on it this entire tank, I got damn near only 200miles. I must just around where you are.

Kevin, Ive seen these compression test kits, but never could figure out how to do it. You put the one end into the spark plug hole, then what? crank the engine and watch the meter while you do this? Do I got to crank it for a couple seconds on every spark plug hole? Aint that a pain? How do you keep it from cranking? Take all the sprak plug wires off?

Dixit

 

No problem!


Yes, it's always good to keep an eye on the EGT. The high temps were telling you something.

 

Here goes good info: http://forums.maxima.org/showthread.php?threadid=95934

 

Good deal, just what I thought.

Dixit

 

thx Kevin! good info.

one more question : those funny whp we read in the beginning. It is low because the car retard the timing? or it is just not enough fuel to generate power?

oh btw, the Chevron on Automall exit on 880 sells 91 @ 2.25/gallon.



Dixit : I know! esp in Bay Area where the gas price is high! (2.25 for 91) It is the wrong time to get boosted.

 

Jesus $2.25? and you all only get 91 octane. Let me ask yall something. Do you get screwed by the fact yall only running 91 octane on boosted cars? Like if you ran 93 would you see a better whp on the dyno?

Dixit

 

I've got the Cartech AND AFC - will be tuning and dynoing next month - I've been wondering if the 2 compliment each other or just cancel each other out.

Guess I'll find out - I figure since the Cartech doesn't start ramping until about 4400RPM, the AFC will be good for the midrange at least.....and maybe even out the upper range, since I haven't been able to tune it to be perfectly flat (Starts at 4400RPM at about 12.1:1 then goes up to 12.9:1)

I've heard it mentioned that 11.5:1 is even better after someone did further testing - who was it that said that? Maybe I'm just confused, as usual.

<sorry if I'm threadjacking>

Good dyno!!! Now tune that sucker and whoop some azz!

 

I really have to say thanx to Kev for figuring out why my car was running lean, and for fixing the problem, and having the chance to tune my max all in the same day. Me and maxi-overdose ( nice meeting You BTW) couldn't have done it without him. Thanx again Kev! Well, the day went hella fast today since we were at the dyno place for almost three and half hours. I don't know if u guys remember, but I posted up a thread trying to figure out why my car was running super lean and why my spark plug had a 0 gap to it and etc... Well.., I went to ATP (dyno shop) cuz Kev invited me to come over so that he can check out if I installed my Aux. pump and FPR correctly. He was checking and checking and everything seemed correct so I was thinking thatI should just order a walbro in tank pump. What was so crazy about this day though was when maxi-overdose began his dyno sessions. His first couple of runs were CRAZY lean! I am not kidding. I am surprised that his engine didn't melt. (That just comes to show how strong our nissan engines are)So, kev and the rest of us were trying to figure out why this was happening. Everything looked to be running right, Aux. pump's wires were installed correctly, no vacuum leaks, I believe he did had some BOV leakage but nothing major to make a super lean mixture, FPR hoses installed correctly, etc.. Kev checks the Aux. pump again and BAMM! HE found out what was wrong. The aux. pump, like mine, wasn't working also. What a coincidence! So, Kev puts on his magic gloves and puts his brain and fingers to work. After a quick minute, we hear a buzzing sound coming from the pump. We were all excited. Luckily, I brought some splicers and some tools just in case we were gonna need them, and well, we did. Once Kev figured it out, he showed us the wires that he spliced in maxi-overdose's car and so we did the same to ours, and what do u know? IT worked for us too! So, all along I have been running without the aux. pump just like maxi-overdose. Well, after maxi-overdose dynoed his max, we ended up dyno tuning mine. Thanx to kev for having the time to tune it for us, we were able to tune it in 1 hour. I believe we had like 20-22 runs in 1 hour! Yeah, my engine was really HOT. We had to let it cool down in little intervals. we were able to get 305 fwhp with the tuning. I wanted a little more but passing 300 is hella cool with me! But anyways, IT was a great day for us!

As for your engine, maxi-overdose, I don't think that nothing major happened cuz if it did, then your car would not be pushin that much power and your car wouldn't feel right. So, it's probably okay. Just do that compression check and from that, u will tell if a cylider is bad. But most likely it should be alright. When I did my compression check, I didn't remove all of the plugs at once. I did one at a time. I pulled the cam sensor plug and the car will only crank but not start. IS this bad? It's the sensor right next to the SC pulley.
All u have to do now is get that baby to run a little leaner and you'll be running a lot smoother. BTW, what is a normal EGT cuz I am only getting like 670 degree C at WOT. Well, I better cut this post cuz it's getting way toooo long! Laters.

~AC

 

Mardi and I found that out.


You're welcome.

Didn't pulling the cam sensor throw a code? I always get a code when I forget to plug the harness back.

Where is the EGT probe located? Tapping higher on the y-pipe will make a difference than tapping lower.

 

yup...91 is highest grade available here in cali because some environmental club was complaining about it. It used to be 92.

oh well.....I wish I can brew my own fuel at home.