[pnanassy]

Hi guys,

since you have more experience with this kind of fuel,i need your help.

The Problem:
at high boost (2.2-2.5bar,36psi) and correct lambda 0.75-0.8,i have serious misfiring (engine bogs).With leaner (0.86-0.9lambda) mixture (i had only 1 fuel pump previously,but now im running 2 044's) the problem is much smaller,but hey,i dont want to melt down the whole thing!

The weakest link is surely the ignition system,which is a stock 3B dizzy setup.Im going to install a CDI box to get some more spark,and i also ordered some cooler sparklplugs.Currently im running stock Bosch F5DPOR Platine plugs,and the had some funny deposits,but were mostly light brown.What kind of plug has the same properties like the stock one but is cooler?Do F4DPOR exists??

Engine spec:
AAN engine,GT37 turbo,tubular manny,Standalone EMS,120lb injectors,2 044 Fuel pumps.

I would like to keep the dizzy setup,and get the most out of it.
Any ideas are welcome.

Thanks,
Peter
11.18@202.5km/h

 

[Matt]

Honestly my best guess is that you just dont have enough spark energy to properly ignite the mixture. I also dont know that I'd be trying to push a platinum plug that hard. I am running NGK plugs in my stock 20vt and they perform as good or better than the F5Ds. I can't remember what Javad runs in his 80tq but that is probably what you need...

 

[yodasfro]

I am running NGK plugs in my stock 20vt

Hey Matt what NGK's did you get?

 

[pnanassy]

Matt your writeup helped me a lot at the beginning.Thank you
What plugs do you use (NGK Code)?
Honestly i dont like the 3-4 ground legged plugs what you mention,all known sources suggest plugs like the stock ones (shape wise).

 

[Matt]

I think I was using a BPR6/7ES NGK plug in my 10vt but they don't fit into the 20v valve cover. The plugs I have in my 20vt are tri-electrode NGK copper plugs. However my 20vt is completely stock. Best bet would be to find a single electrode copper plug that uses the smaller hex and then get the gaps set very even. If you are running out of spark energy a smaller gap may help.

When the rain stops I'll try to have a look at what code the plug is in my 20vt.

 

[SeStone]

A lot of us have experienced issues when running richer than .75 lambda, there's a definite wall where things get too rich and you get power loss/misfires. While I agree that I think you've got a spark strength issue, I'd also verify the calibration on your wideband and any possible air leaks upstream of the sensor--what if when the wideband says you're at .75 lambda, the motor is actually in that 'overrich' point? See the possibility I'm suggesting?

Sam

 

[Matt]

The plugs I am running in my 200 20v are NGK BCP6ET and so far so good...

I agree with Sam on the over-rich problem. On my 10vt if it went anything in to the 10.x:1 range it wasnt very happy.

 

[pnanassy]

Well,the WBO2 sensor is placed just after the turbine outlet.

Did you experienced inconsistent E85 fuel performance?Is that a possible reason?Maybe too hot fuel?I think i have to stage my fuel pumps,because up to 1.5-1.8bars 1 does the job really well.And that way i dont move as much,hence less heat.

Unfortunately i cant find a spark plug in the 8-9 heat range from the BCP_ET series.Also note that AFR 10:1 is just stochiometric for E85.
When i see blacksmoking race engines (a'la IMSA) i wonder how do they ignite that sh!t?

I also checked my dizzy cap and rotor,they have seen better days,so time for new ones.

 

[Matt]

the WBO2 is not supposed to be that close to the turbine outlet, I think they suggest a couple of feet back for best results but that may be just for sensor life.

As for the heat range of the plugs I would think a 7 should be okay. 7 being cooler than a 6 for NGK. My friend GVR4 on MG tried running 8's in his Mitsubishi and didn't really like them. He is running similar times as you and over 500whp on e85.

I have experienced differing performance with e85 from different sources but only enough that it required small tweaks.

Everyone I know making good power from e85 tunes for the 11.x:1 range for best performance. That is at WOT on a gas wideband.

 

[123quattro]

Use this information at your own risk. I have a friend at Roush that has done some engine dyno E85 work. They found max power to occur at 13:1. Also, quality of E85 can vary quite a bit. The alcohol often gets cut with the crappiest gas available leading to inconsistent results.

 

[90_Koop]

How much advance are you running and how much HP are you churning out on that setup? I agree with Sam Et al on spark being your weak link. You may be pushing that dizzy to the point of the spark jumping inside the dizzy to the wrong post.

Could be I'm full of crap.
Anyone...

 

[pnanassy]

My best guess for power is 450-500HP.Thats calculated from my 1/4 time and running conditions(boost,injector DC).

Im running exactly the same amount of ignition advance (10-15degs) as i had on pump gas (no signs of knock at all)

There are lots of much higher powered cars still running on dizzy,so there is definietly a solution to this problem.I found some nicely shaped plugs but they are expensive as hell (Denso IK01-24)

Here is a vid where i had terrible misfires:

Thanks for the tipps!

 

[pnanassy]

Again,it is VERY IMPORTANT to understand that AFR Air Fuel Ratio is a fuel dependent ratio number.On pump gas stochiomertic occours at 14.7:1,but again on E85 its somewhere 10:1(some sources say 9.7,and some 10.7,but its not important).
On the other hand lambda is NOT fuel dependent,thats why its easyer to use in such situations.

AFR 13 on E85 is WAY too lean.

http://en.wikipedia.org/wiki/Air-fuel_ratio

http://en.wikipedia.org/wiki/E85_in_standard_engines

 

[123quattro]

I didn't say it was a good idea. I just said it's where they found max power to be.

 

[Matt]

From what I have read I know that they make WB02 sensors that are calibrated for running alcohol based fuels. I am not entirely sure how it works but here is a thought and I am probably wrong....

a WBO2 that is calibrated for gasoline will always read stoich. ratio as 14.7:1 ... From my experience running my SDS EFI off of the lambda sensor the WB will always read close to 14.7 in open loop even though I am running E-85 and I know it isn't running that lean from the plugs and EGT. So when your WB reads 10.0 you are actually still quite rich, like maybe 7:1 actuality...

this is just from my experience but I have a lot of friends that tune E-85 this way and they don't have any issues due to fuel...

 

[SeStone]

pnanassy, the seemingly rich AFR numbers they're quoting are seen when using a lambda sensor with a gasoline lookup table. IE...the sensor is going to read .75 lambda from the exhaust gases. The controller has a table that says .75 lambda on gasoline says 11.5:1 AFR for that fuel. Most WBO2 controllers don't allow you to change this lookup table, so when someone here says running 11.5:1 AFR on E85...they don't mean that literally, they mean .75 lambda or...7.275:1 AFR. FYI, stoich on E85 is around 9.7:1, but of course leaner is possible depending on the actual alcohol content in the fuel.

Edit: I've also experienced problems when running E85 with gasoline timing numbers, misfires like you state. It must be too retarded to burn correctly. Try adding 4-5degrees of advance in; there shouldn't be any worries about these numbers, as E85 is MUCH more forgiving than gasoline, even if your spark map was bad before it shouldn't cause issues when advanced by that small amount.

Sam

 

[Gringo]

Stock Bosch plugs and 034 high output coilkit with an 034 IIC ECU 2.2 bar boost 600whp with E85 and no worries here.

 

[pnanassy]

We have to be accurate if we talk about such important things.I know what you are going to say to me with this AFR "calculations",but we have to be professional i think...

So you think i can (HAVE TO?) add more ignition advance?Anyone can confirm this?At 2.5 bar boost things happens really fast,even the evil ones

On the other hand,cruising is just like ,-IRC Matt- stated,with 1.1-1.15 lambda its running very well.Tough i dont have an EGT connected to the ECU yet.Is there a possible overheating issu with 40-45degs of ignition advance on the lower load sites?

******,thanks for you experience,what turbo do you use?
And where did you set the mixture in the power region?With 5 coils its a bit easier tough,but hey,ultrahighpower output top fuel dragsters also use dizzy,right?

And again thanks for the feedbacks,
Peter

 

[123quattro]

The more you advance your spark, the lower your EGTs will be. It's a misfire that will really spike the temperature up into the turbo. I'd be careful cruising at 1.15 lambda. That's high.

 

[Gringo]

******,thanks for you experience,what turbo do you use?
And where did you set the mixture in the power region?With 5 coils its a bit easier tough,but hey,ultrahighpower output top fuel dragsters also use dizzy,right?

GT 35/40R .82 AR

I can`t find the log papers at the moment. I`ll look again and see if I can find them.

Paul