05YellowGT

Guy's , are any of you with superchargers experiencing spark blow out. When I first got mine installed last summer , it happened several times and I took it back to Steeda. They found two things , the first was that the battery negative terminal was a little loose. Secondly , I had installed the HT0 plugs myself quite a while before and left them at the factory gap since I was NA then. For some reason Steeda didn't re-gap them when they did the install , so rather than re-gap them , I had them put new ones in. No more spark blow out until about two months ago , when I checked my battery I found my negative battery terminal was corroded. Since it was the OEM battery and had about 40k on it , I put a new battery in and no more spark blow out. That is until last Friday , I checked my battery and alternator over the weekend and both appear to be fine. Is spark blow out due entirely to electrical problems , or can it be a fuel problem ? If it's entirely electrical , it seems like it must be the plugs again. I have a little over 6k miles on the plugs and I haven't pulled them yet to check the gap , but is this something we have do frequently ? Also , is spark blow out harmful to the engine , or just a pain ? Any input would be appreciated , thanks ...

uberPony

Yes it can be harmful to the motor. Gap the plugs to .032 to prvent spark blow out
If you still have spark blow out buy some aftermarket COPs. I have used MSD and Granatelli and both will eliminate the problem 100% and give you some additional power.
My car was getting blow out on downshifts to 1st at WOT. Gapping down eliminated most of the spark blow out but the new COPs completely resolve the problem.

colbymh

I dont have a S/C, but what is "spark blow out"?

uberPony

It happens when high boost pressure blows out the spark plug (s). It sounds like backfiring (popping) in the exhaust.
Resolved through smaller gap on spark plug and or increasing spark through higher voltage.

tom281

My plugs are gapped at .032 and I've never experienced blowout, that's with running around 10psi with a Vortech and soon to now be a Saleen blower.

05YellowGT

Guy's , when Steeda installed the new plugs about 6300 miles ago they set the gap to .030 , or so they said. Would the gap need to be reset already ? I've already changed the stock COPs to the MSD , but I've been told they're the same voltage as the stock ones. Maybe I need to go with the Granatelli ones which are more voltage , but have they worked out the problems we were hearing about with them ?

uberPony

The GMS COPs are an all new design. I have a set in the box I have not installed yet.
Their original COPs had some failure prblems supposedly resolved in these new designed coils.
I already stated that when my plugs were gapped to .032 it did not completely eliminate my spark blow out but helped to a degree.
The GMS COPs will eliminate it for sure. They are 60,000 volts. The MSD COPs are like half the voltage so that may be the issue with your continued problem.

05YellowGT

uberPoly , the MSD's may be less than half of that , I can't find anywhere that the voltage is given for them , but by word of mouth I was told they're the same as OEM at 20,000. That maybe why Steeda set my gap to .030 instead of .032 , so if it's that sensitive then I may need to set the gap again after only 6300 mi. I've seen some at Summit they say are 400% over the OEM ones , that would mean 80,000. Have you heard anything about them , they're considerably cheaper than the GMS ones ...

uberPony

I know Mark (Chevy Killer - ModAddict) is running the Summit COPs on his monster and he has stated that he has been happy with the performance. He was pushing very high boost on his last motor.

max2000jp

Here is my opinion: You shouldn’t be getting spark blowout at 8 psi. If you are running colder plugs and gapped them down properly, something else is an issue. Honestly, I’d run a datalog of your car and send it to a tuner and see if anything is out of spec.

FYI, I am running my HTO plugs at .028 and get no spark blowout.

05YellowGT

Jason , I am running the HT0 plugs and Steeda had my gap set at .0.30 when they replaced the plugs about 6300 miles ago. I talked to them this morning and they suggested changing the gap to .028 , which is what they set for the OEM COPs. I had the MSD when they changed the plugs and they thought the MSD put out more volts than the OEM ones and that is why they set the gap to .030. I haven't found anywhere that the MSD voltage is given , but I have heard that they're the same as the OEM. It doesn't happen often and it may just be that I need the .028 gap like you said , so I going to do that this weekend. However I think I may change the COPs to either the Granatelli or the Summit which both definitely have a higher voltage output ...

max2000jp

Another thing to look at is the condition of the plugs. If they are fouled, you need a oil seperator or breathers. Fouled plugs could cause the car to miss up top too.

05YellowGT

Jason , I have the Magnacharger which is internally oiled and I don't think I have the oil problem that you guys with Centri's have , but I will check this weekend. Once uberPony said that the .032 gap didn't entirely do away with it till he went to the higher voltage COPs , I now think it is the gap/voltage problem. If my gap was set to .030 , then I can see how it might have increased to .032 in the 6300 miles and I would get the occasional spark blow out , it hasn't happened again and I get on it pretty much everyday. Granatelli had a special on their COPs , but the thread is gone so I asked Steve in another thread he had started if I could still get them at the special price. If not I called Summit this morning and their COPs are 50,000 volts and are only $270 for the set. I believe the Granatelli are 60,000 volts and have the zero resistance connectors but are considerably more even at the special price. If I can get them at the reduced price I think I'll go with them and if not I'll get the Summit ones. Thanks for your guy's help and input so far ...

max2000jp

Steve,
I am talking about engine blow-by through the PCV system. All engines exhibit this. For some reason, we get a lot of blow by with the 4.6, especially when boosted. This could foul the plugs, which could cause them to break up.

05YellowGT

Jason , gotcha and I will check this weekend. Thanks ...

05YellowGT

Jason , are you running the OEM COP's at the .028" gap ? I checked with Steeda and they gap the plugs at .028" for them and I believe they're 20,000 volts. I currently have the MSD COP's and that is why they had the gap set to .030". I had heard that the MSD were the same voltage as the OEM ones , but I finally called MSD yesterday and found out they're actually 36,000 volts. More than the OEM , but not as much as the Granatelli or Summit. I got hold of Steve at Granatelli and was able to get a set of theirs for the reduced price. So I'm trying to decide what to gap mine at with their COP's , not sure if I want to use the .032" uberPony is using without problems , or leave the gap at .030" because of the higher voltage COP's , or go ahead and gap them at .028" like you just to be safe. Would there be any down side to using the smaller gap if it wasn't needed ? Thanks for the info so far ...

max2000jp

I am using the OEM coil packs. Decreasing the gap helps prevent spark blow out, so I see no issue with you going to .028. That's what was recommended to me.

Burke0011

Dang Steve - I hope you get this issue locked down asap!

05YellowGT

Dave , It's only happened a few times and all except the last one I tracked to the battery or the plugs , so I'm pretty sure it's a gap/voltage thing. uberPony was getting it and went down in gap to .032" and it helped but didn't completely eliminate it with the stock COP's , and I believe he even tried the MSD ones. He said once he went to the higher voltage GMS ones it eliminated it completely. It happened last Friday and the last time it happened before that was about 6500 miles ago. At the time Steeda replaced my plugs and they set the gap to .030". I can see how the gap might have widened to .032" since then and the MSD's were no longer making enough spark. Jason is running a .028" gap with the stock COP's and said he has never had spark blowout. I got the GMS ones coming in today and I'm going to install them and replace the plugs this weekend and I figure this should cure it. I just can't decide what gap to go with , since uberPony is fine with them at .032" the .030" that they're currently set to should work. However , I temped to go down to the 0.28" which would give me longer before the gap should need to be reset. By the way , how did the scan gauge turn out ?

Burke0011

Gauge install 'rescheduled' for this weekend

I ran by a buddy's place for 5 minutes on Sunday to drop off some tools while he rebuilt the front brakes on his Suzuki TL1000...... four hours later, I had just helped him finish the job.

(oooops)

Felt like I needed to help him out as his brakes were more essential at the time than my gauge. I am planning on Sat morning (and I got a splice tap for the TPS 5v line so getting that power now should be fairly simple)

Hey I want to mount my MAP sensor right where you have yours - no issues drilling into the firewall there correct?

OH - what vacuum line did you T- into for the sensor?