I posted a few weeks ago about my Dump Valves no longer making any noise (and not dumping)...

 

I started thinking about when it stopped and realised that i'd used Ordinary Unleaded (95 ron) when i 1st got the car and Super UL (97 ron) ever since.....

 

It was about this time i started noticing the valves not working..

 

SO - on Sunday i used 95 ron again and 100 yards out of the garage............ Bitsshhhhhh!!!

 

They work!?!?!? How odd...

 

Ive a TT 2+2 Jap, i thought it would need at leat 97 ron (maybe 100) as it was an import?!??!?

 

Help anyone?

 

ps. what the HP supposed to be on a 300?

I can't answer the dump valve question as thats a little strange. I'm sure there is a logical explanation for it.

 

A Stock 300zx TT should give you about 280BHP at the fly.

I only use Super or Optimax and mine always dumps (J-spec TT)

Ive used both as my nearest SHELL is some way away and doesn't make any difference to my bov's. (can't see how it would!)

 

James.

I just doesnt make sense!

 

I could kinda of understand the other way around (Higer fuelling and higher turbo pressure?). But no this!!!

 

Oh well, performance doesnt appear to have suffered so i may stick with the cheap stuff!!

 

Dan

Did you notice a reduced amount of boost pressure at the same time?

Possibly with the lower octane of the normal unleaded caused a bit of detonation and your Z went into safety boost as a result, and therefore a reduction in boost which may cause the "Silence of the valves"?? :D

Dave

I have a dodgy tick over problem. I think it's the throttle bodies need cleaning.

 

Anyway going to clean them this weekend.

 

But to summarise optimax seem to elevate the problem!!!!

danhock - what type of dumpvalves are you using. If they have a moving part in side them, have you thought about a bit of WD40 maybe?

 

At one point I thought my dump valves went quite but just put it down to me getting use to them.

 

wesmi01 - when you clean your throttle bodies, if you are going to use a PLASTIC toothbrush, be careful as your stroke in and out not to scrape the toothbrush along the throttle flaps because they are very sharp and can shave bits of your toothbrush off, which could end up going through the system. Apologies if sucking eggs are involved here.

Ive got Blitz Dump Valves. Dont know which model as it came in from Japan like that!!

 

Cant see moving parts....

Originally posted by DaveW

Did you notice a reduced amount of boost pressure at the same time?

Possibly with the lower octane of the normal unleaded caused a bit of detonation and your Z went into safety boost as a result, and therefore a reduction in boost which may cause the "Silence of the valves"?? :D

Dave

 

Definitely sounds the most plausible to me. Good thinking Willo !

It would make sense but the boost hasnt dropped. Also it seems to boost more (the vavles dump) with lower octane fuel....

Originally posted by danhock

It would make sense but the boost hasnt dropped. Also it seems to boost more (the vavles dump) with lower octane fuel....

well this makes no sense atall.

but on the Blitz dump valves youll find a littel screw at the top in which you can adjust them for noise levesl ect.

 

if you unscrew the valve all the way out, and then screw it back in till you feel it connect with the pin, they should be set at there maximum?

worth a try?

Cool will try it!!

 

Thanks guys.

Has any one made a dump valve buy cutting the return pipe on the recircs?