Autothority banjo bolt
 

update on post #15

Hello, I'll have the autothority dme and klr chips for my 1986 951 soon, but I still need the special Banjo Boost bolt which has an "air correction jet."

Does anyone have an extra one to offer up? I'll buy it! Or is there an alternative?
Please feel free to pm me.
Thank you fellow rennlisters.

Found one already. Thanks rennlist!

Where did you find? I can't tell if I already have this upgrade or not.

The autothority company can sell just the bolt for $50 if you call. I was able to find one used. it replaces the bolt on the large intercooler pipe. psi reach 15.

Can't wait! gain claim is 48hp.

Here is 1988 turbo S comparisom. all stock vs chips + jetted banjo bolt.

http://members.rennlist.org/jjbare/88SRStockDyno.jpg
http://members.rennlist.org/jjbare/8...horityDyno.jpg

An additional 48hp from changing the bolt? Sounds fishy. I already have the Autothority chips (or they may be APE, possibly same thing), but still can't see where to buy this at. I believe I have the stock bolt, but am not positive. Part isn't listed on autothority.com.

The APE banjo bolt reduces the boost detected by the stock WG, so you can run up to 15 PSI (11 PSI stock) without the stock waste gate opening. Inexpensive way to increase boost. Let me know if you need a APE bolt.

Is APE an acronym?

I believe ape stands for autothority performance engineering

ALSO, you can perform the mod on your stock bolt, for the price of a $2 drill bit. just sayin.....

How is this done? Have you tried it, kev? I thought the conversion was more involved.

Autothority banjo bolt on the right.
http://www.clarks-garage.com/phpBB2/...olts-2_115.jpg

there is clearly a restricter in there. not rocket science.

My current 951 came with this installed. At first I didn't know WTF it was, or why it was there, but a quick internet search (here, mostly) made it clear.

It (well, mine anyway) has the interior of the banjo drilled and tapped to accept a #135 carb jet Mine even had ".135" sharpie marker written on the banjo.

Now, the question is, does this simple wastegate "trickery" to 15 psi without supporting fuel/air mapping (chipset) mean things are going to go "bang"?

I better dig into my mystery box (dme) and see what's in there exactly....the previous owner of 8 years had no clue what it was or how it got there. (friend of mine) so I am not that worried.

I am guessing the APE banjo bolt is intended to be a supporting mod of their chip stuff?

Jeff

Yeah, that bolt comes with klr and dme chips for turbos. With only a bolt, air is rerouted and goes unchecked so I think that may not be so good, though i'm not sure.

You know the LBE (Lindsey Boost Enhancer) may also work for you. It's an adjustable spring-loaded valve that prevents the wastegate from opening until the spring force is overcome with boost pressure.

The idea of the jetted banjo bolt is just to restrict air pressure from going to the wastegate so it reacts slower (if it opens slower, more boost pressure will be achieved).

I have an update!

I decided to go with the two autothority chips and bolt. I have an all-stock '86 951, and it's finally very well sorted and running strong.

I started by installing just the chips and the improvement was significant and exciting.

Then I decided it was "safe" to install the bolt, and I did. At this point, the improvement in power was truly incredible -- especially for a dated 4-banger! The stock gauge consistently showed just under 2 bar, which is expected, but the massive power increase prompted me to err on the side of caution; I've removed the jetted bolt until the new boost gauge comes in, so I can get a reliable boost reading. I'll report back once it's installed.

VDO Cockpit International Mechanical Turbo Gauge
http://www.vdo-instruments.com/instr...gauge-12v.html
http://www.vdo-instruments.com/media...011c_front.jpg