I thought this was due to me using 87 octane gas... but now on 93 octane... i'll floor it.... hit full boost 10-11 psi... and only reach 1050-1100 deg. F, and about 80-90 psi fuel pressure... What gives? The car is soooo sluggish... like it's slower than i was before i supercharged...

I know my tranny is goin out.... but I don't see how that'd cause my egt temps to be so low... I mean it's obvious that I'm running super rich, but my f/p doesn't reflect that....Thoughts?

 

Your maxima is punishing you for running 87 octane poison. How dare you. Check yer fuel filter. Sounds like a clog or something, and if not that then check yer fuel pump. Is yer fuel pump upgraded?

 

he has the right fuel pressure...that elinminates the possibilies of fuel pump and filter.

possibily the injectors are maxxed out?

 

Could you be detonating?? How are your plugs?

 

Haven't pulled plugs.... injectors are not maxed out since I'm only hitting 90 psi tops.

Looks like I'm pullin plugs today after work! yay!

 

The low EGTs indicate a very rich afr, which is consistent with the high fuel pressure and sluggish performance. Just for reference, I'm running a 6:1 disc with a 3.25" pulley and hitting 1450F at 9 psi, with fuel pressure at 65-70 psi. The car feels really strong, although I haven't dyno-tuned yet.

 

Thing is, until last week, i've been hitting around 1350 egt's.

 

Oh. Yeah, you better take a look at the plugs and do a compression check.

 

Are you running 1 or 2 steps colder and 8:1 disc? I can't believe you weren't getting preignition/detonation boosted with 87octane. Egts are much lower I would say that is due to the higher octance fuel change. The hotter egts were probably a sign of some mild preignition.

 

90psi is pretty hard on the injectors already.....I think most injectors become erratic after 65psi.

I would start with plug on cylinder no.5.....the last one on the fuel rail usually gets less fuel.

question for all:
I just recently re-gapped my plug to .035......and I noticed that my cruise EGT is much lower (610 celcius at 80 mph, 2700rpm) on a flat road. Does it have anything to do with smaller plug gap?? 740celcius after boosting. I have 1step colder and 8:1 @ 10psi.

thx

 

pulled plugs... they're fine... slightly brown with some carbon buildup on the first couple of threads.

Anyhoo, I did notice that if you look straight down towards the ac compressor from the engine bay... the alternator is clearly turned clockwise about 5 degrees.... and when in gear with the brakes, the alternator and pulley vibrate harshly... Think this could be the reason for all the damn noise?...

Hopefully tonight i'll do a quick tear down and see if i can align it.

 

update: I removed the drive belt and started the car..... and put it into gear, no rattles at all... so it's gotta be this dayam alternator ....