What is the max boost (in bar) that your 951's give you.

 

It's 'supposed' to be .8. That's stock. It's easy enough to modify.

Why do you ask? Are planning mods?

It's usually easier and more accurate to use psi as a unit of measurement.

All things working sorrectly, the stock 951 will start to bleed boost at 7 lbs I think. The wastegate will be open by 12 lbs.

 

i'm getting 1.4 bar stock and with the guru chips i'm getting 1.8

 

Mine is modded and has a Lindsey dual-port wastegate and a manual boost controller, so I'm able to set it to basically whatever. I've got it set to about 14psi right now and that nearly pegs the stock gauge to the far right (I also have an aftermarket gauge to really see what I'm getting).

Weak wastegate springs can limit what you're getting as they start bleeding boost sometimes when you're way down in the single digits.

Cheers!

 

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by '86 944 turbo:
<strong>i'm getting 1.4 bar stock and with the guru chips i'm getting 1.8</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">If you're using your stock gauge, the first line is atmospheric pressure (no boost, no vacuum) so your boost is .8 bar.

 

isn't 1.8 bar like 25 psi. i think i'm gettin to much boost.

 

okay i get it

 

just took the car for a drive got 2 bar boost. so thats about 15psi right.

 

1 bar is 14.8 psi. It is a unit of measurement based on the atmospheric pressure at sea level. If you are standing on the beach in Florida, the atmoshphere is exerting 14.8 pounds of pressure on your body.

How that works into engines: All engines are essentially air pumps. N/A cars alwasy work at vacuum (unless they use ram-air which just reduces the vacuum) meaning there is nothing to push the air into the engine. They rely on piston movememt to pull air into the cylinder.

With turbos and superchargers, the turbine will push air into the engine increasing air volume and the potential for power.

When your boost gauge reads 1 bar, it is measuring 1 atmoshere meaning there is no vaccuum. You turbo is pushing just enough air equal normal atmospheric pressure. Anything over 1 bar on the stock gauge is boost. So when you are seeing 1.8 bar it's actually 1.8 atmospheres or .8 bar of boost.

I hope this is a useful explaination without being insulting. I don't know how you know about engines so I explained it Barney style to cover the basics. I don't want to come accross as condescending.

The best source of knowledge about turbos is Corky Bell's book <a href="http://search.barnesandnoble.com/booksearch/results.asp?WRD=maximum+boost&userid=2T0802XA84" target="_blank">Maximum Boost.</a> I re-read once a year or so.

 

By the way .8 bar of boost equates to about 12 psi which is the pressure at which the stock wastegate will be fully open (all things being stock).

 

thank you streckfu's951 for your info.

 

So when my stock boost gauge gets up to 1.6 bar, I'm not really getting much boost?

 

It's hard to read the stock gauge and they tend to be inaccurate anyway. If you are seeing 1.6 bar, you are generating 1.6 atmospheres but only .6 bar of boost which is normal. Boost is considered anything above 1 atmosphere (or 1 bar). I don't think there is anything wrong with your car at all (maybee a pessimistic boost gauge at worst).

<img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" /> <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />