Race Car Tech Discuss anything related to road racing and auto X.

sources for detination @ 13psi and up???

Old 07-20-03, 10:07 AM
  #1  
Senior Member
10 Year Member
Thread Starter
 
pistonsuk's Avatar
 
Join Date: Oct 2002
Location: Portland, OR
Posts: 685
Likes: 0
Received 0 Likes on 0 Posts
sources for detination @ 13psi and up???

hi,
i have an '87 t2 that i have built from the ground up myself. mods list:
E6K w/3bar
fuel pres gauge
egt (approx 800 deg C under full load)
j&s knock (stupid thing keeps lighting up)
FMIC
full exh.
T78
550 pri
1600 sec
walbro 255
fp reg (44psi static)
street port w/ Hurley 3mm
wideband tuning (cruise=14.4, <5psi=12.5-13.5, >10psi 10.0AFR)

i am writing this b/c i am completely frustrated about the fact that i can still see detonation @ 13psi and up!!! this cost me 1 engine already @ 6000miles!
i think that 93 octane on this set up should be able to support 16-18psi. am i right?? please look at the following and tell me any suggestions that you have:

fuel AFR's= cruise=14.4, <5psi=12.5-13.5, >10psi 10.0AFR

timing= from 3k rpm to 8k rpm- 30deg adv @ 0psi, linerized to 12deg adv @15psi

trail split (>2k rpm)= 10deg @0psi, 2deg @ 5psi, 10deg @15psi (linerized between points listed)

corrections:

timing vs. intake air temp= starting @ 100deg 1deg ret per4-6deg temp rise

fuel vs. intake temp= i have it taking away very little to nothing above 100deg inorder to further richen the mixture

the thing is this engine is NOT leaning out. the detonation is coming from something else. i am baffled. i feel those timing values are already too conservative. can an engine detonate from being too rich? is it possible that small imperfections in the rotor housings/side plates could allow blow-by igniting the next charge? please forward any input that you have. thanks for your time.


justin

513 518 1994
pistonsuk is offline  
Old 07-20-03, 12:42 PM
  #2  
Rotary Enthusiast
10 Year Member
 
Join Date: Apr 2001
Location: North Hollywood, Ca USA
Posts: 1,289
Likes: 0
Received 0 Likes on 0 Posts
pump gas is so inconsistant that running this aggressive a setup is going to be disasterous. Unfortunately you have found that even with good tuning problems can arise. I would not use pump gas on any modified turbo engine, especially one that is run at over 13psi of boost. you can try reducing the timing even more to try and help, but race fuel is really the only way to cure this problem. what are the intake air temps? this is likely the real culprit. intercooler is heat soaked and then you run it wide open and bang the detonation. race fuel is going to have more octane which is resistance to detonation. on my turbo race motor which only ran 10psi of boost I had to run race fuel to keep it alive. it lasted three seasons of racing without any damage. only problem was I had worn the apex seals, but everything else was in good shape. try some race fuel and see what happens. good luck
tims is offline  
Old 07-24-03, 11:25 PM
  #3  
Full Member
5 Year Member
 
Join Date: Jun 2002
Location: New York
Posts: 217
Likes: 0
Received 0 Likes on 0 Posts
umm, where can you get race fuel from exactly???
red xeven is offline  
Old 07-25-03, 10:08 AM
  #4  
Ex fd *****
10 Year Member
 
maxpesce's Avatar
 
Join Date: May 2001
Location: Ventura CA USA
Posts: 1,782
Likes: 0
Received 0 Likes on 0 Posts
Originally posted by red xeven
umm, where can you get race fuel from exactly???
At The RACE TRACK

Out here in CA lots of Union 76 dealers will sell you race gas in 55 gal drums or dispensed into your own container (it is illegal for them to dispense it directly into your street car) In the EAST you should try your local SUNOCO dealer, their Std. Premium is 94 octane , and I think many may still dispense 101 octane super premium gas at the pump.
It really sucks that we can only get 91 octane pump gas out here in CA

Last edited by maxpesce; 07-25-03 at 10:11 AM.
maxpesce is offline  
Old 08-01-03, 01:22 PM
  #5  
mythical Unicorn
iTrader: (1)
 
Join Date: Mar 2001
Location: Boise, ID
Posts: 342
Likes: 0
Received 0 Likes on 0 Posts
Fuel

I do not know if this will help you but I run a 3rd gen with up to 18 lbs of boost on stock turbos. I am running the highest octane unleded fuel I can get. It is K & S 103-107 octane. That along with all the other mods keeps me save. To date I do not know of anybody else running the boost I do. I have had no problems at all.

Car was tuned by Kogi at XS Engineering to run the boost I said with the fuel I am using.

Hope that helps.

Allan
Spank is offline  
Old 08-01-03, 11:17 PM
  #6  
RE for life
 
diyman25's Avatar
 
Join Date: May 2002
Location: sca
Posts: 1,180
Likes: 0
Received 18 Likes on 15 Posts
race fuel

AIR PLAN FUEL. those rate 120. and is much cheaperthan race fuel. the only problem there are lead and my friend tell air plan fuel is different than car feul.
use on my friend car doesnt seen to had problem
diyman25 is offline  
Old 08-09-03, 11:21 PM
  #7  
Rotary Freak
10 Year Member
 
Marcel Burkett's Avatar
 
Join Date: Nov 2001
Location: trinidad and tobago
Posts: 2,715
Likes: 0
Received 0 Likes on 0 Posts
12 Degrees advance @ 15 psi may be too much for pump fuel !! , you should be around 10deg max or even lower than that.Find out where torque peak for the engine is and retard the timing to about 5 deg at that point , do this at the RPM ranges just before and after that point also from there you can carefully go up a degree at a time , if the gains are minimal then revert to the prior lower value. Advancing the ignition on a rotary doesn't make such a big difference to power but it will cause you to detonate , ask me how I know !! , as for the split I was detonating at 0 deg advance with 5 psi boost because my split was too close!!!.
Marcel Burkett is offline  
Old 08-14-03, 07:00 PM
  #8  
Function > Form
 
rotor vs. piston's Avatar
 
Join Date: Nov 2002
Location: Catonsville MD (baltimore suburb)
Posts: 10,890
Likes: 0
Received 0 Likes on 0 Posts
Also scence your building it yourself, check for small burs on the rotor. These can become excsively (sp) hot and cause detonation.
rotor vs. piston is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
NotMrButts
1st Generation Specific (1979-1985)
25
02-10-18 06:36 PM
PinkRacer
2nd Generation Specific (1986-1992)
43
10-01-15 09:13 AM
stickmantijuana
20B Forum
9
09-22-15 07:39 PM
Shainiac
Single Turbo RX-7's
9
09-21-15 05:02 PM


Thread Tools
Search this Thread
Quick Reply: sources for detination @ 13psi and up???


Contact Us - Archive - 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: