Last Lemming

I posted this in the water cooled forum, then thought, wait, there is turbo forum, so I'm posting it here too. Sorry for the X-post.

So my 86 951 came with a Vitesse chip (with 3 shims in waste gate) and the boost knocks off at 1.75 bar on gauge. I installed my Lindsey 3" and now in third gear I'm seeing 2 bar at wot.

What is the simplest way to drop this back to 1.75? Would removing another shim do it? be the answer. I would think not since that would limit 1st and 2nd gear WOT.

Or is the OEM waste gate just being overwhelmed? What is the boost limit on the stock WG.

thanks for any help.

Last Lemming

I was just informed that 2 bar = 15 psi. If this is the case then I should be fine since that is what the 3 shims are suppose to be limiting the boost to.

mtnman82

If you're using the stock boost gauge on the cluster, yes 2 bar = 1 atm (~14.7 psi). You'll notice when at idle that gauge sits at 1 bar (atmospheric).

I remember picking up a couple pounds boost without touching anything when I installed my 3" exhaust.

Scott H

You should really get a mechanical boost gauge to make sure, the ~$40 they cost is cheap insurance to make sure you're not making too much boost.

Gator_86_951

I second the mechanical boost gauge. I would suggest you get an a-pillar pod with a boost gauge and an oil temperature gauge. It also wouldn't be a bad idea to get a manual boost controller either.

Last Lemming

I want to keep the stock look, but I suppose I could hook one up temporarily just to check.

Scott H

I can understand that, if you don't want to keep taking it on and off then you may consider mounting it in the glove box so it's hidden but you can still peek at it whenever needed.

SirLapsalot

You could just get a cheapish pressure gauge route it through the cowl and through the passenger window. Then just have someone observe it while you drive. I have a 930 boost gauge with the tell tale needle I use for this type of diagnosis. Consider that as an option if you don't want to have a permanent gauge mounted.