Hi guys,

I'm a turbo newbie with an important question, so please bear with me and have a little patience. It's my very first post.

I just bought a 1987 944 Turbo that I'm picking up April 15th. It has a K27/6 turbo, Porsche Turbo Cup DME/KLR chips ad a Lindsey Racing boost enhancer.
It has a K&N filter & a cat exhaust but with a performance cross-over pipe.
I want to run the maximum safe boost on premium pump gas without worrying about detonation or the engine management computer cutting off fuel.

I'm told this turbo makes 17psi, but that I have to use 110 octane at that boost level.

Can I just dial the boost enhancer to 15psi and run with that safely on the street on pump gas? I tend to wind out the gears to almost at redline before shifting & would like to do that with this car - but without blowing a head gasket or worse! Excuse my newbiness, but I really need an answer!

Z51944

 

I have seen other cars that have similar parts; in fact my car has the same turbo, has been chipped and will soon have a homemade boost enhancer put on it. I run my car with 93 octane and it works just fine as does several other car that I have seen on the interwebs. There are also plenty of dyno sheets showing cars with 17 lbs. of boost running 93 or 95. If you are worried that much about pre-detonation you can monitor the knock sensor to see if there really is a problem. I am sure there is already a thread on rennlist covering this topic. That all being said, I think your fine using pump gas.

 

The LR boost enhancer does not control your boost pressure. It only delays the pressure signal being sent to your waste gate (to reduce lag).

Since it sounds like you have a stock waste gate and no boost controller, your max boost is being controlled by your "turbo cup" chips and is not adjustable.

IMO, with the right tune and proper monitoring (wideband O2 display), it is possible to run 17psi on 91 octane even.