AFR ratios, whats too lean.

[302 Hi Pro]

Will try to log my car tomorrow to see what it runs like with the x pipe fixed and pump gas. Luckily I have a contact with a major fuel supplier here in Chile and next week I should have an Idea of whats available down here as far as fuel goes. Looks like aviation gas is the most likely candidate. Whats VP gas? not familiar with the term. So far have not seen or heard of E85 or E98 but will start looking.

My plan is to try to convince Shaun to tune my car!

I guess that until I have the tune issue sorted out its not worth getting a 84.5mm TB and Airaid CAI?

Hi Mad Hatter:

No, and I would say that installing a new TB & CAI might make the problems worse. Wait till she is sorted and Sean agrees to tune. Then have Sean write your Tune program to optimize all of your bolt on parts and install them and download Sean's new tune for your car.

She should run better than ever before. As for the fuel terminology, My impression was that Rick was referring to your statement regarding Avaition Gas, some times referred to as "AV" gas, (AV is slang for Avaition).

Hope this helps,
302 HP

 

[VoodooBoss]

I've run AV gas in my MX bikes with no issues. Make sure you know what you're buying and that it's unleaded! I ran VP racing gas in my karts. Is VP available in Chile?

http://www.vpracingfuels.com/

 

[Mad Hatter]

Thanks, might be importing some VP gas! Will wait to see what the specs are on the aviation gas first though. I heard its about US$2/liter making it the budget choice. Will hold off any engine mods till the tune is squared away.

 

[302 Hi Pro]

Looks like a run to Delaware is in my future to pick up on some AP C-10 or perhaps C-20? Does anyone have any experience with running either of these two fuel blends?

I'm thinking of using this for my annual Atco Dragway trip that I began in May of 2014. So far, the Boss is 3 - 0, running consistent 12.6's on 50 - 60% worn stock PZeros.

Will be interesting to see if there are any improvement this year.

Have fun,
302 Hi Pro

 

[Mad Hatter]

Dam and blast, AV fuel in Chile has lead in it. If I took out the Cats can these engines run safely with a little lead?

Brazil has loads of ethanol fuels but have not found any here in Chile. And importing fuel seems to be very expensive with tons of paper work.

Hope to log the car tonight or tomorrow morning to see if the evap hose that was melted shut might have made caused the fuel starvation problem.

 

[302 Hi Pro]

Trace amounts of lead in your fuel would take out your catalytic converters so once those are removed you might be ok.

Looking at this from the other side, the issue with non leaded fuels in cars designed for leaded fuels centered around the valve seats and the use of non leaded fuels would eventually lead to burnt valve seats.

To convert these older cars to understand leaded fuels you would have to relief cut the valve seats and install hardened valve seats.

So other than cats, I don't know of any issues to the engine mechanical bits, but leaded fuels in the Boss maybe problematic for things like fuel injectors. I'm just not sure but other BMO members will chime in and let us know about these issues.

Now that we have learned to make Big HP on unleaded fuels, no one really has a need to experiment with leaded fuels.

Keep us posted on your findings.
All the best,
302 HP

 

[Swiss Boss]

I think it can f*** up the O2 sensor too

 

[VoodooBoss]

While I think Dave's assessment is spot on I still would not run leaded gas in your car. There are too many unknown's regarding electronics and valve train to chance it. My only caveat is that if you talk to one of the race teams like CorteX Racing or Phoenix Performance and they run leaded gas and have no concerns then go for it. Also check with Shaun at AED.

 

[steveespo]

Leaded fuel and O2 sensors are not compatible, contamination will cause bad things to happen and the car will go into closed loop operation. 93 octane is safe for track operation even with Track Key although I would not use it. In mad hatter's case I would have the car tuned by Shaun at AED, he will request data logs of the engine under load and tailor a set of tunes that will give all of the Track Key functions and a real performance boost, while ensuring that AFR and timing events are as safe or on edge as you wish to make them with the fuel available.
Steve

 

[302 Hi Pro]

Interesting notes on leaded fuels in the US. It was introduced in automotive fuels in the early 1920's, this was to help the auto manufactures improve engine life and eliminate knock and wear on exhaust valves and seats.

It was not until 1995 or 1996 that the U.S. banned all lead in gasolines used for public streets. Some leaded fuels are still available today for Off Road Use only.

Aviation fuels for pistion driven aircraft engines still use fuels lead additives. Today this is the leading cause for lead contamination in our air.

Lead is a natural occurring heavy metal that does not degrade or evaporate over time. It's extremely toxic and dandelions stuff!

Stuff I didn't know,
Dave

 

[Mad Hatter]

Yup, I guess AV fuel is out. Was going out to log the car now but by luck, saw a great big crack in my rear disc. ..... New discs are already on the way and hope to have the car up and running soon.

Can't wait to log the car again and see if the melted shut evap tube and leaky exhaust was the cause for the wonky readings. I forgot to take my sct4 to the track last week, but with the fixes the car was noticeably faster.

 

[Mad Hatter]

Do you have access to E85 or E98?
E85 would be an ideal fuel for the Road course, and if can't get E85 but can order 54gal barrels of E98 you can mix your own to 15% gasoline and 85% Ethanol.

So far Sunoco 104 octance turns out to be about US$14/gallon placed in Chile!! Busily trying to find E85 here in Chile, looks like it might arrive soon. For E85 I guess its a tune and 60lbs/in injectors? If I got a hold of E10 would that help any??

 

[Mad Hatter]

Well they came back.... Things seemed better after we found/fixed a crack in the x pipe. But this weekend the code came back at the end of a track day. I logged the car and at WOT my measured AFR for bank 1 is 0.83 and my bank 2 is 0.93. What could be giving one bank lean?
Could it be something like a injectors, filter, bad wiring or O2 sensor.... Or something more scary like valves or number 8 piston? Car runs great and had no problem keeping up to a pair of ZL1 with headers and such.

At idle bank 1 is jumping between .98 and 1.04 compared to Bank 2 that just sits at fixed at 1.

On further reading....

Code P2254 read sensor negative current control circuit open. Bank 2 sensor 1
AND P0153 O2 sensor slow circuit response. Bank 2 sensor 1

I guess first thing tomorrow to change a O2 sensor.

 

[Mad Hatter]

Changing O2 the sensor in the lean bank brought the measured Lambda down to 0.83 and the engine codes have been gone for a week so far. What a relief!!

 

[Mad Hatter]

Sorry about the monolog! After a review of the logs by Shaun..... Time to take the heads off and peak at the pistons apparantly. Dire warnings of impending melt down have left me in the dumps. Beware people! Looks like running LTH and x pipe alone with questionable fuel and stock tune can lead to possible/probable engine damage. No codes for a while but.............

Will run compression test and stick a camara down the plug holes first. Then pop the heads off.

 

[TMSBOSS]

Have you considered pulling the plugs and looking inside the chambers with a scope?

Cheaper and you may see what you need to see without pulling heads.

I am a bit old school. Compression and leak down tests along with the scope could confirm the internal condition without pulling the heads.

I would hate for you to tear down the engine and find no damage.

 

[Mad Hatter]

Great Idea, looking for some one with a scope right away! Funny thing is that I feel no loss of power, high water temps or cel lights.

 

[sadil]

I am curious as to how a leaking x-pipe would cause lean codes... I have had two consistent codes throughout the life of my LT's and X-Pipe and those were P0420 and P0430, both related to the cats not being present. However, after a couple months with no cats and LT's I remember I was getting another code which was more concerning. I cant for the life of me remember what it was. I spoke to Shawn and he scared the hell out of me regarding the code I spoke of and told me to check my O2 sensors. The sensor mfg recommends that the O2's be installed on an angle so that water vapour can drain out of the sensor. LT mfg's dont bother having the bungs on an angle and the sensor sits flat. When I took a look at my sensors, the bank with the code had a front sensor which was burned out. To check and make sure, I removed the sensor and installed it on the other bank and the code switched over to the opposite bank. I had custom bungs drilled, capped the old ones, and replaced the sensor and never got the code again. I never tuned my car after that and run the stock tune since I always had trouble with my iTSX SCT device which was showing very wonky A/F ratios.

 

[Mad Hatter]

I really have no idea what was throwing the codes. I do know that since I changed the O2 sensor for the Bank with the code. I have not had any more CEL's. Shaun did a great job of scaring the hell out me but I am completely puzzled now. His readings of my codes puts me in the melt down imminent category and he was crystal clear he wants nothing to do with my car since its been too thrashed according to the logs (though he was a gentleman about it and offered advice). I made 9 WOT pulls in five min and that puts me in danger zone due to running too lean. What I do not get is that at the track I have the car at WOT a lot of the time for 7min sessions at least 5 times per event. I have not had water temperature problems or noticed any unusual heat after session. I track the car two or three weekends a month now. I have not gone into limp mode for over a year and no other inpending doom codes either. Obviously if some one like Shaun tells you watch out you would be a fool not to listen so I will get a hold of a camera and do a compression test as soon as the car comes out of the body shop (Finally repairing a trip to the tire wall from a while back) Once I sort it all out I will have look for another tuner, which I must admit is disappointing..

But take care!! my only engine mod is a Kooks LTH and X catted Xpipe. Shaun mentioned that I am suffering from a car not tuned for its mods.

 

[Mad Hatter]

Some screen captures of my logs while I find a scope to look in the engine.

Here is a image of the first pull I did a WOT

Right after I coasted down to 3000 rpm I made another pull

The second WOT has the the Lambda reading stuck till 5600 rpm, it then drops downs 0.84 very sharply. Of the five pulls I did, three were like the first one and two were like the second. Have no idea whats going on and looks like same goes for all the shops I have talked to down here so far. Any comments very welcome!