I was on the dyno yesterday with my 150 shot and i melted cylinder #7 and 1 spark plugs. At the end of last season i melted 2 and 5 at the track. They are gapped at .038 and im using 100 octane through a standalone. Timing is at 24 degrees total advance and the afr is right at 11.0-11.5. What is the deal??????????????

Alex

 

are you having any lean spike issues?
Are you absolutely sure about the timeng? What are you using to retard or control timing?
Are you certain its a 150 shot? TNT is known to under rate the jets. It makes no difference what they call a set of jets...what comes out is what actually comes out.

Whats your rpm activation points and are you having massive TQ spikes due to low rpm activation? Even a 150 shot at 3000 rpm (especially from and under rated kit like a TNT) can induce detonation if it hits hard and fast.

Are you monitoring for knock?

Obviously you are experiancing detonation. Need to find the cause.
If you dont find any obvious things...take another 2 degrees out of timing and step up to 104 unleaded in the standalone.

 

Hard to say with what you have given us. If it is a lean Spike as mentioned I would shorten the fuel line to get the fuel to hit sooner and cover the spike.

NX Jeremy helped me dial mine in and I learned alot

 

What plug are you using? I would hope you are using more than a TR6. And I would gap them tighter too.

 

Im using tr6s gapped at .35,should i use something else? Its being monitored with hptuners by Straightline Performance on their dyno with a wideband. We had zero knock the timing is 24 for sure. The line to the fuel solenoid is only about a foot long. There is pretty much no lean spike and the afr was at 11.5-11.0 the whole run. On initial runs the afr was really rich because we were dialing in the standalone. It was activated at 3400rpm and im using the standard tnt 150 jets.

 

Might be time to move up to a Nirto Dave plate or a DP and better distribution

If you are getting good AFRs out of BOTH sides and still melting plugs things are not well.

 

Sounds good so far. Are you certain the 100 octane is a full 100? No mixing?

I would empty the main tank of your car and put 100 in there too.
Or maybe step up to 104 in the stand alone.

You could also get some plugs that are one more heat range colder. I believe NGK BP7EFS or som ething like that. There is a stiky in this section for plugs.

You cant be melting spark plugs and NOT getting knock??

I suspect your TNT kit is really spraying quite a bit more than the intended 150 shot. And at low rpms you are getting a small amount of detonation.

You have a few paramemters to change around to eliminate that.
Increase octane
further reduce timing
raise the rpm activation point closer to 3800-4000
go dual stage of say 80 at 3000 and then another 80 at 4500.

 

This whole thing really bothers me because ive been running this kit for 3 seasons. 1st season was a bolton car only,2nd was 224 cam only then 224 cam heads and fast. Now its a bigger cam with the rest the same. Cam in sig. If i get a step colder in plugs what should i gap them at? Any one else have any ideas on changing spark plugs or anything else.

 

You can try a ngk 7 or you can take more timing out.If it was me i would take timing out to about 20 and the try to creep up to about 22(taking fueling is good).Just remember just because someone else is running x timing doesn't mean your car will like it.Track tunes and dyno tune will change so dont get dissappointed if your tune was good on a dyno and you go to the track and it dosen't acted the same.Its just part of the game and dyno are desined to get you in the ballgame.

 

it may be a distribution problem. sounds like a couple random cylinders are getting more n2o/fuel then others.

 

Im going to try the colder plug. Im also going to see if i can get either my tuner or someone with hptuner to come with at the track and tune on spray there. Its hard to tune this thing on the spray with on a dyno. The 4000 stall just flashes to high. I think the track is going to help.

 

A couple of noted issues here -

One - You must keep in mind that the wide band is only picking up the combined O2 ratio of the cylinders. If some are richer than others then it may even itself out once mixed in the exhaust. If you have an EGT meter it could tell you volumes about the cylinder it is measuring but it would require some not so pretty cosmetic work on the headers.

Two - Some cylinders create a stronger vacuum signal due in part to the manifold design and can be robbing other cylinders of the needed fuel.

Three - I see that you are running a ported head but am not sure if it is a 5.7 head or not. As such what is your static compression ratio? The reason that I ask is that 24 degrees overall doesn't really tell us much in that the N2O may require less timing up top where as you can get away with a little more in the lower RPM ranges depending on compression and cam profile.

Four - As stated I would be looking at fuel distribution. With the injectors that you have I would try adding some fuel to all of the cylinders and then work backwards. I would use nothing less than 110 octane to start with. Fouled plugs due to a rich condition are always easier on the mind and wallet than burnt ones are.

Five - A 150-hp shot on one system is not always the same as another. One reason for this is that some rate their gains at the wheels while others rate them at the flywheel. Having said this more octane, fuel and perhaps a little less timing would be in order for now. Then work your way up slowly and check your plugs after each change. Technology is a wonderful too but sometimes we must resort back to our roots to resolve certain issues. Pull those plugs and read them carefully!!!

Jim C.

 

Last year i was on no standalon and no 100 octane and i had no problems for probably 30 bottles. Untill the last run of last year when i melted 2 and 5. And last year i was running 27 degrees. This is why i think something is faulty in the system.

 

What Kind of dyno are you using?

In the past when we used a Dynojet to tune we would have to add 10-20% more fuel at the track.

The Mustang Dyno we use now is ALOT closer if not dead on most times.

Richen it up and try some TR7's , I would even take a few degrees of timing out.

 

could your fuel pump be going out? Do you have a good pump in it? Could the fuel solenoid be sticking shut?

You could always put a tr-9 plug in the car too, if you suspect the plugs are too hot and that's causing your problem put those in there, if it's a plug only isue, I bet thise won't do it.

I'm guessing you have a fuel pump going to hell, or the fuel filter is clogged, something like that. If you've been using the kit for a while and not having issues, and now it is, I'd be looking at the fuel side of things first.

Put the timing back to about 20 degrees too, you're better off starting out on the mild/safe side of things then doing what you are doing.

 

The fuel pump is fine. Its a brand new standalone system with 100 octane. What would be any disadvantage of running a colder plug if any. Why would every one run the coldest possible.

 

less chance of detonation with a colder plug. The fuel pump in the main tank could be on the fritz too.... not just the standalone.

 

At a point, your car would start to stumble a little while in traffic (low rpm driving), then clear up once you started moving again. I highly doubt 7s would cause any ill effects.

 

The intank is a brand now racetronix and i have a guage in the car to monitor. It stays right at 55-60psi. Im going to try the tr7s. Im also sending the solenoids back to tnt with the dyno graphs and plugs.

 

do you have a wideband in the car? if so what does the a/f ratio look like on the track?

FWIW, we always set mine to around 11:1ish on the dyno back when i had a stalled auto because it would always lean out at the track under load.