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

HIGHEST OCTANE USED on modified turbo engines ?

Thread Tools
 
Search this Thread
 
Old 03-02-04, 03:24 PM
  #1  
Senior Member

Thread Starter
 
Join Date: Feb 2004
Location: MIAMI,FL
Posts: 319
Likes: 0
Received 0 Likes on 0 Posts
HIGHEST OCTANE USED on modified turbo engines ?

while doing any kind of event like drag racing , road racing where race gas is easily available . has anyone used the leaded type race gas that is 112-116? . ive used only the unleaded 100 but was wondering has anyone mixed these 2 types together or what are the negative effects for using small amounts of leaded while racing with no catalytic converters . does anyone here have any previous expierience with high octane race gas(leaded and unleaded) and boost .?
thanks
jose vela
85 gsl-se turboII conversion TO4E
ran with 100 octane but want higher
Old 03-02-04, 03:28 PM
  #2  
trying to build a racecar

 
Travis R's Avatar
 
Join Date: Sep 2002
Location: Austin, Tx.
Posts: 580
Received 1 Like on 1 Post
Not with boost... but leaded 114 smells really cool.
~$6.50 a gallon
Old 03-02-04, 03:58 PM
  #3  
Senior Member

Thread Starter
 
Join Date: Feb 2004
Location: MIAMI,FL
Posts: 319
Likes: 0
Received 0 Likes on 0 Posts
travis thanks for the input

jose
Old 03-02-04, 04:09 PM
  #4  
Full Member

 
25BP's Avatar
 
Join Date: Jun 2003
Location: Denver CO
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
I run 100 octane here in Denver, as the octane points are consistanly lower. It would equate to around 104 at sea level. I have never had any issues with it, and would recommend it for boost.

Like Travis states, there is nothing like the aroma of race fuel!
Old 03-02-04, 04:50 PM
  #5  
Lives on the Forum

 
rynberg's Avatar
 
Join Date: Dec 2001
Location: San Lorenzo, California
Posts: 14,716
Likes: 0
Received 8 Likes on 8 Posts
There's no point in spending the extra money. Also, the lead will kill your o2 sensor.

If your car is already tuned using 91-93 octane, 100 octane is good insurance for the track. There's nothing to be gained by running higher.
Old 03-02-04, 04:59 PM
  #6  
Rotary Enthusiast

 
tims's Avatar
 
Join Date: Apr 2001
Location: North Hollywood, Ca USA
Posts: 1,289
Likes: 0
Received 0 Likes on 0 Posts
If you are running a full race prepared turbo engine then the octane will give you added detonation protection. this is vital in turbo rotaries. I ran my turbo 13b for 2.5 years of racing on 110 octane Unocal leaded race gas. After initial tuning the engine ran perfectly until time had worn the apex seals. never had any detonation and aside from normal wear the internals were fine.
Old 03-02-04, 06:40 PM
  #7  
Rotary Freak

iTrader: (10)
 
gnx7's Avatar
 
Join Date: Mar 2001
Location: San Francisco, CA
Posts: 2,085
Received 18 Likes on 9 Posts
If you plan to really turn up the boost then race gas is cheap insurance. I could run 8* more timing at the track with 10psi more boost with C16 (116 leaded for turbo motors) vs. 93 octane unleaded in my little turbo V6.

You can get heated O2 sensors which are less prone to failing.... or an aftermarket fuel management system with wide band O2 are designed to handle race leaded fuel.

$8/gallon vs. a popped motor. You decide.... racing ain't cheap.... and it is more expensive if you cheap out on the fuel quality when pushing the envelope.

Mixing 100 octane with 116 octane will have no adverse effects aside from the O2 sensor failing. You can take 100 octane and add Xylene (117 octane) to raise the octane level and remain unleaded.

HEre is the recipe the TurboBuick guys have run with no ill effects:
7 gallons 100 octane
3 gallons Xylene (117 octane)
3 ounces MMO (Marvel Mystery Oil) for lubrication

yields 105.1 octane....... you aren't supposed to mix in more than 30% Xylene or it starts hard with cold weather and drives weird. It is a trick from the old Group B rally cars when they would run 40psi+ boost.....

-GNX7
Old 03-02-04, 07:26 PM
  #8  
Senior Member

Thread Starter
 
Join Date: Feb 2004
Location: MIAMI,FL
Posts: 319
Likes: 0
Received 0 Likes on 0 Posts
thanks for the info everyone

thanks everyone for your valuable info . i guess we can use the 116 leaded but will kill o2 sensors and cats as well if we are using them. other than that its ok , i will finish installing my profec-B , egt guage as well so that i can try and use the recipe GNX7 provided at my next race . and for now ill be runnin with 100 just for safe peace of mind .
again i want to thank you all for your time in explaining me this octane bug i had in me .
jose vela
85 gsl-se TurboII conversion TO4E
Old 03-02-04, 08:31 PM
  #9  
Mad Man

 
Carl Byck's Avatar
 
Join Date: Jan 2002
Location: Big Island Hawaii
Posts: 2,758
Likes: 0
Received 2 Likes on 2 Posts
Below ~25psi, 100 has been reliable for me, In my Supra, I'll run 116 when running 30+ psi, other than that, I run 100.
Old 03-04-04, 12:04 AM
  #10  
I can has a Hemi? Yes...

iTrader: (2)
 
Directfreak's Avatar
 
Join Date: Dec 2001
Location: 3OH5
Posts: 9,371
Likes: 0
Received 4 Likes on 3 Posts
Originally posted by gnx7
Mixing 100 octane with 116 octane will have no adverse effects aside from the O2 sensor failing. You can take 100 octane and add Xylene (117 octane) to raise the octane level and remain unleaded.
Where do you get Xylene?
Old 03-04-04, 11:08 AM
  #11  
Rotary Freak

iTrader: (10)
 
gnx7's Avatar
 
Join Date: Mar 2001
Location: San Francisco, CA
Posts: 2,085
Received 18 Likes on 9 Posts
Open up a business account (free) at any major paint store and buy it in 5 gallon containers. I got mine at Sherwin Williams for about $31-33 per container.

-GNX7
Old 03-05-04, 01:02 PM
  #12  
Rotary Enthusiast

 
mikey D's Avatar
 
Join Date: Mar 2004
Location: Pensacola FL
Posts: 848
Received 10 Likes on 10 Posts
I checked on prices because cheep high octane sounds good.

But i can buy real race gas for the same price or less.

Its only $6.80 a gallon for 116 sunco unleaded race gas.
Its only 4.25 for 110 sunco unleaded race gas


Its allmost 7 dollars a gallon for your xylene
and toluol is only a little less expensive
you have to run 100% of either to get their 114 to 116 octane rating


It doesnt sound like such a good idea now huh. =)
Old 08-19-04, 03:38 PM
  #13  
Gone domestic

 
blacksupra94's Avatar
 
Join Date: Aug 2003
Location: Raleigh, NC
Posts: 370
Likes: 0
Received 0 Likes on 0 Posts
Bump on an old thread, would it be safe to use a gallon of xylene, and two ounces of marvels mystery oil with an almost full tank , just to clean my injectors?
Old 08-19-04, 05:45 PM
  #14  
Rotary Freak

iTrader: (10)
 
gnx7's Avatar
 
Join Date: Mar 2001
Location: San Francisco, CA
Posts: 2,085
Received 18 Likes on 9 Posts
blacksupra- that won't hurt anything and many use it clean their injectors a few times a year. It is one of the main ingredients in the injector cleaners you buy from your local autoparts store.

Making your own 100 octane isn't necessarily cheaper.... but if you don't have access to it then it certainly is an option to use.

-Mark
Old 08-19-04, 07:04 PM
  #15  
Learned alot | Alot to go

iTrader: (2)
 
CrackHeadMel's Avatar
 
Join Date: Apr 2002
Location: Rotaryland, New Hampshire
Posts: 4,232
Likes: 0
Received 0 Likes on 0 Posts
6.50 a gal for 114?? sucks for you, im getting 55gal's of 116 at 4.40 a gal
Old 08-23-04, 09:43 AM
  #16  
built my own engine

 
93BlackFD's Avatar
 
Join Date: Dec 2002
Location: Buckhead, Atlanta
Posts: 3,470
Likes: 0
Received 2 Likes on 2 Posts
you need at least heat range 11 spark plugs (non platinum) for leaded gas
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
alphawolff
1st Generation Specific (1979-1985)
17
11-17-15 05:57 PM
Frisky Arab
2nd Generation Specific (1986-1992)
13
08-18-15 05:30 PM
rx7brandon
General Rotary Tech Support
3
08-16-15 10:55 AM



Quick Reply: HIGHEST OCTANE USED on modified turbo engines ?



All times are GMT -5. The time now is 10:47 PM.