detination, how can you tell when its happening

yamaha_junky626 · Sep 2, 2010

i have a turbo d700 that i was wondering how you can tell if there is detination before it is to late. it does have the sensor in the pipe, i'm assuming that just turns on a light when it detects it. does that system work good enough to trust it with a turbo setup. i,m using an air fuel ratio gauge for tuning, from what i've heard when it starts detinating your numbers goes lean is that correct, also would a exhaust temp setup be better for detecting detination or won't it show anything. i only have like 3 rides on my sled so i'm not to familier with the setup yet. i have also heard about the plugs unscrewing with detination. i was running about 4 gallons race fuel per tank around 12 psi and that is about where i would like to stay for boost level any less just isn't near as fun. my plan this year is to used torco fuel accerator instead of race fuel just cause i can bring a smaller quanity of that versus race fuel along. price is about the same.

sled_guy · Sep 2, 2010

The DET sensor is not in the pipe, it's attached to the head. And yes, it works very well... it will work on the turbo.

If DET happens at part throttles, assuming you don't have stupid loud pipes, you can often hear the difference in the motor.

From a signs to look for standpoint:
1 - If the plugs work loose, WARNING WILL ROGERS, you have DET
2 - If the top of your piston, especially around the outside, looks sand blasted, DET
3 - If after it breaks and you pull the pistons there is missing material between the piston rings or the ring locator pin is missing it's very likely DET.

sled_guy

t_thall · Sep 2, 2010

gray speckels on the plug or piston are another sign. IMO i would stick with the race fuel versus the accelerator. The accelerator is pretty good but not as good as proper fuel.

yamaha_junky626 · Sep 3, 2010

detination

ok is see where the detination sensor is , i was thinking someone had told me it was in the exhaust which didn't really make sense considering that automotive ones all on the engine blocks. thanks for the info guys.

victorsledneck · Sep 10, 2010

Most of the time you can increase the % of octane if you see the sandblast on the plugs and pistons. Like it has been said, listen to your motor for pings or hammering. If you don't catch it quick enough you just spent some more coin on pistons/possibly cylinders which could go towards more gas. Depends on type of turbo, but there may be something with the turbo system making detonation happen like hobb switches. I was detonating on 50% mix had to up my % of octane to avoid the detonation and ran like a champ with no problems other than it is more expensive now to put fuel in the sled, but the increase octane fixed the deto. My buddy up'd his octane but went through 3 more pistons until he realized the hobbs switch was bad. Replaced it and cut the % back down and ran great. Just some food for thought.

francois · Nov 20, 2010

Hey guys, I have a major det problem on my td8. I rode it for the first time today and it won't go w.o.t. cause it will just back fire non stop. Not too fun to hear and see lol.

I was riding at 0' today with straight avgas. I started with closing the boost controler just to see if that would work. To my surprise, when I was accelerating I saw up to 10+ psi and obviously it started to det.

I think it's the wastegate that is not working properly because like I said I don't seem to have any control on the boost...I assume it stay closed all the time having as a result a full boost.

It was -10celsius today so yes the air is dense but I will be riding at this weather and colder (way colder), hope I can make it work!

I also checked the boostline going to the attitude box to make sur it wasnt blocked or anyting thinking it could also be a reason for det if there was no fuel added when b oost kicks in.

Anyone has a idea to solve my problem?

thanks

theshadowrider · Nov 20, 2010

victorsledneck said:
Most of the time you can increase the % of octane if you see the sandblast on the plugs and pistons. Like it has been said, listen to your motor for pings or hammering. If you don't catch it quick enough you just spent some more coin on pistons/possibly cylinders which could go towards more gas. Depends on type of turbo, but there may be something with the turbo system making detonation happen like hobb switches. I was detonating on 50% mix had to up my % of octane to avoid the detonation and ran like a champ with no problems other than it is more expensive now to put fuel in the sled, but the increase octane fixed the deto. My buddy up'd his octane but went through 3 more pistons until he realized the hobbs switch was bad. Replaced it and cut the % back down and ran great. Just some food for thought.

What is a Hobbs switch?

Arcteryx · Nov 20, 2010

fuel

yamaha_junky626 said:
i was running about 4 gallons race fuel per tank around 12 psi and that is about where i would like to stay for boost level any less just isn't near as fun. my plan this year is to used torco fuel accerator instead of race fuel just cause i can bring a smaller quanity of that versus race fuel along. price is about the same.

Not claiming to be an expert but I am wondering if 40% race fuel is enough at 12lbs of boost. If it is in "the range" I'm pretty sure that's in the lowest part of the range. Most of the guys I ride with mix 50% from 8 to 10lbs and run straight race fuel at 12lbs and above.
Not saying it won't work, just saying I think that puts you at an extremely high risk for detonation. JMO.

supraturbo · Nov 20, 2010

i run my td8 2009 at 12 lbs boost and i m riding at an average of 1000 feet elevation on 50% 116 octane and 50% 91 octan and it is running like a charm! very often you will see your a|f gauge go lean but in fact it is too rich si it goes crazy! be careful

Arcteryx · Nov 20, 2010

AF

supraturbo said:
i run my td8 2009 at 12 lbs boost and i m riding at an average of 1000 feet elevation on 50% 116 octane and 50% 91 octan and it is running like a charm! very often you will see your a|f gauge go lean but in fact it is too rich si it goes crazy! be careful

Good point on the AF gauge. I tend to forget that because I don't have one, nor do the 3 turboed buddies I ride with. I know a lot if not most of the serious turbo guys swear by them. We have done EGTs and try to read the plugs but an AF gauge would certainly answer more questions.

If your running 116 octane at a 50-50 mixture you would still be running higher octane than YJ. I am assuming (never a good idea), that he is running 110 or maybe 112. At a 40% mixture of 110 he would have an average octane of about 98.6 per gallon. At 50% mixture of 116 you would be at about 102.5 average octane per gallon. That 4 octane per gallon difference could be pretty big. I might be doing my math wrong here. Just my thoughts. Something to look into.

francois · Nov 21, 2010

Supra turbo,

thanks that is exaclty what Im seeing right now on my afr gauge.

Je suis de chicoutimi en passant, j'aurais besoin de ton aide!

supraturbo · Nov 24, 2010

appel moi pas de probleme!

Eli · Dec 8, 2010

supraturbo said:
i run my td8 2009 at 12 lbs boost and i m riding at an average of 1000 feet elevation on 50% 116 octane and 50% 91 octan and it is running like a charm! very often you will see your a|f gauge go lean but in fact it is too rich si it goes crazy! be careful

Which 116 are you running?

Klimbing Kitty · Dec 8, 2010

sled_guy said:
The DET sensor is not in the pipe, it's attached to the head. And yes, it works very well... it will work on the turbo.

If DET happens at part throttles, assuming you don't have stupid loud pipes, you can often hear the difference in the motor.

From a signs to look for standpoint:
1 - If the plugs work loose, WARNING WILL ROGERS, you have DET
2 - If the top of your piston, especially around the outside, looks sand blasted, DET
3 - If after it breaks and you pull the pistons there is missing material between the piston rings or the ring locator pin is missing it's very likely DET.

sled_guy

Det Sensors do work but you can not count on them always. they are just a tool. I have squeaked and I have a det sensor. You have to look at all things........ elevation Egt's, A/F gauge, plugs, wash, fuel is a huge factor. If you are looking to push the boundaries of fuel vs boost you will eventually go boom.

ridgeclimber · Dec 8, 2010

DET sensor

As I have posted before. Some guy's like myself have had problems with the det sensor acting up. I have adjusted boost, fuel ratio's, fuel #'s in the control box. Then I figured what the problem was. Make sure you change your fuel filter every year. It's not that you need more octane, you might just need more fuel. An afr gauge would help determine that.

snowx22 · Dec 9, 2010

theshadowrider said:
What is a Hobbs switch?

hobbs switch is a small switch that boost referenced, for example if it gets 3 psi of boost it closes two electrical leads - so there is a boost line from my carb to the hobbs switch that has power coming in and a wire going out to a selenoid that opens and lets fuel get pumped into a power jet - at 3psi of boost I get a bunch more fuel in the mid range.

jhurkot · Dec 10, 2010

supraturbo said:
i run my td8 2009 at 12 lbs boost and i m riding at an average of 1000 feet elevation on 50% 116 octane and 50% 91 octan and it is running like a charm! very often you will see your a|f gauge go lean but in fact it is too rich si it goes crazy! be careful

can anyone explain how the a/f gauge shows lean when it is in fact too rich? i've heard of this before but would like to know the science behind it. thanks.

tree climber · Dec 10, 2010

i think the sensor kinda fouls out with un-burnt fuel on it and doesnt read correctly... i had it explained to me but cant remember what i was told so im just guessing now sorry haha

theshadowrider · Dec 10, 2010

jhurkot said:
can anyone explain how the a/f gauge shows lean when it is in fact too rich? i've heard of this before but would like to know the science behind it. thanks.

It works by sensing oxygen/fuel ratio via voltage. Fuel ratio is determined by the o2 sensor sensing a certain voltage. The voltage of an afm or o2 sensor is very low so it doesn't take much to mess it up. .5 volt is optimum and .1 is lean, .9 rich. Read on below.

Wheel House Motorsports · Dec 10, 2010

not to try and pick a fight, BUT, IMO, thats not the issue with the missreading at all..

oxygen sensors just sense the amount of oxygen in system, in our case, the exhaust, they have no idea about fuel, they cant sense it. what happens is, you have a rich missfire, its so rich it wont burn. now you have raw fuel and at the same time pure oxygen running throught the exhaust.. thats whats goin on, normally the oxygen is consumed in the combustion reaction, now its just passing throught your motor.. nothing happening to it.

detination, how can you tell when its happening

Member

Well-known member

Member

Member

Member

Well-known member

Well-known member

Banned

Well-known member

Member

Banned

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Well-known member

Similar threads