[Peter]

Hi, today I have hit 28,96 psi on BPU - I have A/F monitor - it was rich but I am wonder if that is safe...

What are your experience?

I thought 23psi is max for BPU...

 

[RSA Supra]

Might be safe as far as A/F, but EGT's would probably go through the roof plus your turbo's won't last long.

Mani hit ~2.17 bar a few times in his car a few eeks later it was smoke time... But of course now he a has a T-66, so everythings ok.

 

[Peter]

OK, than what is safe boost for bpu?

 

[Guest]

when i was BPU i was boosting around 22 PSI

i would say 18-20 PSI on stock turbos.. 20 PSI is pushing it.. all it is doing is overheating the turbos

 

[pooshda]

Yea... im never gonna run over 20psi again... (if I get another set of stockers)... The weather caused boost spikes of around 24psi.. and I quickly killed my new turbos that way..

Next time Im gonna run like 16psi daily, and 18-20 when racing only probably.. I cant afford to go through turbos like this anymore

 

[Peter]

I will set it at 1.5 Bar = 21.75 psi and I will use it only during races, daily driving - not more that 1 Bar.
What do you think?

 

[Guest]

when you said your A/F monitor reads "rich" what was the A/F ratio?
GEnerally 18psi stock twin max out....I remeber this from huge discussion long ago everywhere on the forum.

 

[Peter]

when you said your A/F monitor reads "rich" what was the A/F ratio?
GEnerally 18psi stock twin max out....I remeber this from huge discussion long ago everywhere on the forum.

I have K&N A/F monitor and it shows red - lean, yellow - OK, green rich. I had all green lamp on = I was very rich.

Do you remember discussion details? Anybody had made some Dyno tests or that was just said 18psi max???

 

[Guest]

dont remember detail...too much to remember. but basically anything above 18 the stock turbo moves out of its efficiency range. I think it produces more heat than power.

K&N makes A/F monitor? wow, never heard of that!
does it use wide O2 sensor? you should get one of those that reads out A/F ratio in #s so you know exactly where you are at. green, red and yellow just dont cut it. its like saying "the car felt faster".
you should be around 11.5-12:1 range. no higher. anything below 11.5 is probably a BPU running without a fuel controller (too rich).

 

[Peter]

Yes it uses wide O2 sensor.
I have scale on it from 17.1 (lean) to 12.1 (rich) around 3000-4000 rpm I am at 14.7 At full boost I am at 12.1 but that is the end of scale.