Notices
924/931/944/951/968 Forum Porsche 924, 924S, 931, 944, 944S, 944S2, 951, and 968 discussion, how-to guides, and technical help. (1976-1995)
Sponsored by:
Sponsored by:

Autothority banjo bolt

Thread Tools
 
Search this Thread
 
Old 07-27-2012, 03:35 PM
  #1  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default 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.

Last edited by bonus12; 08-18-2012 at 10:08 PM.
Old 07-27-2012, 04:47 PM
  #2  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default

Found one already. Thanks rennlist!
Old 07-28-2012, 04:26 AM
  #3  
Sentinelist
Pro
 
Sentinelist's Avatar
 
Join Date: Jun 2010
Location: North Dallas, TX
Posts: 733
Likes: 0
Received 0 Likes on 0 Posts
Default

Where did you find? I can't tell if I already have this upgrade or not.
Old 07-29-2012, 12:44 AM
  #4  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default

Originally Posted by Sentinelist
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.



Last edited by bonus12; 07-29-2012 at 01:39 AM.
Old 07-29-2012, 05:45 PM
  #5  
Sentinelist
Pro
 
Sentinelist's Avatar
 
Join Date: Jun 2010
Location: North Dallas, TX
Posts: 733
Likes: 0
Received 0 Likes on 0 Posts
Default

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.
Old 07-29-2012, 07:22 PM
  #6  
bw993
Rennlist Member
 
bw993's Avatar
 
Join Date: Feb 2005
Location: San Diego
Posts: 1,053
Likes: 0
Received 20 Likes on 20 Posts
Default

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.
Old 07-29-2012, 10:35 PM
  #7  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default

Is APE an acronym?
Old 07-29-2012, 10:56 PM
  #8  
dillon410021
Race Car
 
dillon410021's Avatar
 
Join Date: Dec 2007
Location: LaPorte, IN 46350
Posts: 3,835
Likes: 0
Received 10 Likes on 10 Posts
Default

I believe ape stands for autothority performance engineering
Old 07-30-2012, 12:33 PM
  #9  
kev951
Burning Brakes
 
kev951's Avatar
 
Join Date: Jan 2010
Location: San Mateo, CA
Posts: 1,000
Received 15 Likes on 14 Posts
Default

ALSO, you can perform the mod on your stock bolt, for the price of a $2 drill bit. just sayin.....
Old 07-31-2012, 05:49 PM
  #10  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default

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

Autothority banjo bolt on the right.
Old 07-31-2012, 06:37 PM
  #11  
kev951
Burning Brakes
 
kev951's Avatar
 
Join Date: Jan 2010
Location: San Mateo, CA
Posts: 1,000
Received 15 Likes on 14 Posts
Default

there is clearly a restricter in there. not rocket science.
Old 07-31-2012, 06:45 PM
  #12  
ditch68
Racer
 
ditch68's Avatar
 
Join Date: Oct 2008
Location: Tucson, Az
Posts: 346
Likes: 0
Received 0 Likes on 0 Posts
Default

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
Old 07-31-2012, 07:01 PM
  #13  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default

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.
Old 07-31-2012, 07:29 PM
  #14  
Van
Rennlist Member
 
Van's Avatar
 
Join Date: Oct 2002
Location: Hyde Park, NY
Posts: 12,007
Received 88 Likes on 58 Posts
Default

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).
Old 08-18-2012, 10:07 PM
  #15  
bonus12
Three Wheelin'
Thread Starter
 
bonus12's Avatar
 
Join Date: Jun 2010
Location: Northern California, '86 951
Posts: 1,693
Received 25 Likes on 22 Posts
Default

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



Quick Reply: Autothority banjo bolt



All times are GMT -3. The time now is 03:30 AM.