Notices
928 Forum
Sponsored by:
Sponsored by: 928 Specialists

Sharktuning experience

 
Old 02-09-2019, 06:10 AM
  #61  
Marti
User
Thread Starter
 
Marti's Avatar
 
Join Date: May 2011
Location: Edinburgh, Scotland
Posts: 504
Likes: 0
Received 0 Likes on 0 Posts
Default

Well I have finally hit a limit with advance, recorded some big X knocks high up under load and a couple of random smaller knocks lower down in the rev range.

Also I noticed the last lot of advance didnĺt seem to translate into any extra performance.

I am also bringing in the level of richness at high load high revs as it was running to rich, it was way down at 12 AFR.

I am doing all the adjustments in excel now which referring back to the SP overview of the runs.
Marti is offline  
Old 02-09-2019, 07:35 AM
  #62  
FredR
Addict
Rennlist Member
 
FredR's Avatar
 
Join Date: Jun 2005
Location: Oman
Posts: 5,892
Likes: 0
Received 0 Likes on 0 Posts
Default

It would be interesting to know just how much advance one can add when the air temps are around zero C. I tend to tune my motor at night in the summer time to be safe - the air temps are a bit more reasonable by then down to around 35C.

For what it is worth I was advised that the 928 head design produces max power at 13 to 1. Stock tunes deliver AFR's in the low 12's and one presumes that is to give a margin of safety.
FredR is offline  
Old 02-12-2019, 04:04 PM
  #63  
Marti
User
Thread Starter
 
Marti's Avatar
 
Join Date: May 2011
Location: Edinburgh, Scotland
Posts: 504
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by FredR View Post
It would be interesting to know just how much advance one can add when the air temps are around zero C. I tend to tune my motor at night in the summer time to be safe - the air temps are a bit more reasonable by then down to around 35C.

For what it is worth I was advised that the 928 head design produces max power at 13 to 1. Stock tunes deliver AFR's in the low 12's and one presumes that is to give a margin of safety.
Hi Fred

I am going to be targeting that 13:1 ratio high up in the rev range. It is pretty close elsewhere in the rev range but the last 2 or 3 maximum load levels in the fuel map just dumped fuel in at silly rate. I am hoping to test tomorrow night and see what is happening.
Marti is offline  
Old 02-14-2019, 06:26 AM
  #64  
drnick
Super User
 
drnick's Avatar
 
Join Date: May 2002
Location: New Zealand
Posts: 2,774
Likes: 0
Received 0 Likes on 0 Posts
Default Latest ignition


Marti, heres my current map - it goes well My rpm points are no longer standard to pull back timing where I was seeing some knock. Like everything its still a work in progress.
drnick is offline  
Old 02-14-2019, 03:02 PM
  #65  
Marti
User
Thread Starter
 
Marti's Avatar
 
Join Date: May 2011
Location: Edinburgh, Scotland
Posts: 504
Likes: 0
Received 0 Likes on 0 Posts
Default


Hi

Funny, our maps are not to far out from each other. Pictured above is my current map, the orange box is where I got some recent knock and pulled the timing back slightly. I actually found I could run 10 degrees more than the 25 degrees I am currently running by dumping in fuel but this was not translating to any extra go, rather the opposite.

So now I am optimising fuelling and tweeking timing. I think I am reaching the end of the road with tuning for this set up.

I am hoping that the next time I have to ST when I change the manifold will be a lot faster because of what I have learnt so far.
Marti is offline  
 


Thread Tools
Search this Thread

Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: