| Author |
Message |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 234
Registered: 7-2002
| | Posted on Sunday, February 16, 2003 - 11:33 am: | |
Thanks for all the opinions everyone. For now, I'll most likely stick with what I've got. There aren't any misses with the reduced plug gap. The car runs very strong. Guess I just have never benn able to be satisfied with anything "as is". |
James J. McGee (Dr_ferrari)
New member
Username: Dr_ferrari
Post Number: 9
Registered: 7-2002
| | Posted on Saturday, February 15, 2003 - 8:55 pm: | |
Jeff,
Best to stick with the OEM wire set. they fit perfect, resistance values are to ferrari spec. and perform very well. Changing the wire set to anything aftermarket, in my opinion would not give any advantage.
Best regards, Jim |
Ernie Bonilla (Ernie)
Member
Username: Ernie
Post Number: 539
Registered: 11-2001
| | Posted on Saturday, February 15, 2003 - 7:41 pm: | |
Speaking of plug wires, do any of you have experiance with Nology Hot wires? |
billy bob (Fatbillybob)
Junior Member
Username: Fatbillybob
Post Number: 204
Registered: 8-2002
| | Posted on Saturday, February 15, 2003 - 7:14 pm: | |
Well the custom 348 set I have from magnaecor has the built in extenders and a rubber cap on the end to keep dirt out of the plug holes in the valve cover. They are just sloppy and do not fit anyway near as good as the OEM Ferrari seal. The wires rock in the bore of the valve cover holes and the rubber caps just cover but do not seal. Maybe Magnecor ripped me off or I'm a picky SOB? |
JRV (Jrvall)
Member
Username: Jrvall
Post Number: 951
Registered: 11-2002
| | Posted on Saturday, February 15, 2003 - 6:22 pm: | |
>>is the fuel burn less efficient, or even incomplete?<<
no not at all..a miss is incomplete...once it fires again you have explosion...the hc #'s would tell you how complete the burn of the combustion explosion is.
the spark only ignites the mixture at the tip of the plug area (not the entire chamber)which is why you don't need a big gap or long spark unless you have a very lean mixture (lean needs more time for the fewer molecules to be ignited to create propagation), that small ignition propagates to the entire chamber as the resultant explosion we call combustion, that the piston then compresses.....mixture is critical to spread a combustible mixtire throughout the entire chamber for the maximum amount of explosion possible for the amount of area availible.
very lean or poorly designed chambers need a huge spark (relatively speaking) while richer mixtures and well desined chambers need much less spark for propagation. |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 233
Registered: 7-2002
| | Posted on Saturday, February 15, 2003 - 5:49 pm: | |
Yes, I have looked at all fuel/air mixture readings. As a matter of fact, Bob Norwood himself tuned the car on the dyno. He adjusted the fuel /air mixture at all rpms and downloaded to the motec unit. He showed me where the plug was dropping on the duno sheet and told me to just close the gap a little to about .019. I did. It in fact doesn't miss any more, but I was wondering with the gap closed down like this; is the fuel burn less efficient, or even incomplete? What do you think?
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JRV (Jrvall)
Member
Username: Jrvall
Post Number: 945
Registered: 11-2002
| | Posted on Saturday, February 15, 2003 - 11:12 am: | |
Have you taken fuel mixture readings and pyrometer numbers under boost in the range it's missing at? or at least read the plugs?
it could be a fuel mixture problem.
On the High HP, High Boost Turbo Porsches I build an additional Fuel Controler adds gas under certian conditions to eliminate leaning down/lean misses and exhaust temp spikes. |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 232
Registered: 7-2002
| | Posted on Saturday, February 15, 2003 - 9:16 am: | |
A few things here.
According to Magnecor the problem is EMI. Electro magnetic interference. RFI is Radio frequency interference. Both are problems, but for different reasons. EMI can cause problems with signals received by your engine management computer. RFI causes radio interference.
I currently suffer from niether.
I called MOTEC. Interesting conversation with their engineer. He said that solid stainless core wires most likely wouldn't cause a problem with the EMI, (which was my concern). I'd interfere with radio reception though, (no big deal). The MOTEC box is internally sheilded fairly well. He said no way wires can add horse power BUT, (and it's a big but), if you are getting weak spark, you may be losing power in the combustion chamber form ineffecient/ incomplete fuel burn. A better burn would certainly add power! So there may be some power to be RECOVERED. Interesting.
I've looked again at my wires. I've spot tested a few for ohms. They are as stated, no degradation. So, I'm switching first to Denso Iridium plugs, same as I put in my old 308. I'll see if they hold up a better spark.
|
John J Stecher (Jjstecher)
Member
Username: Jjstecher
Post Number: 354
Registered: 1-2002
| | Posted on Friday, February 14, 2003 - 10:49 am: | |
Billy Bob do you have a set of Magnecor wires on your 348? I got them a while back and think that they fit very well to the head and seal every bit as well as the original plug wires did. I agree 100% with you that there is no performance gain by running these wires versus factory wires unless you had a wire problem already, but when you consider they are way WAY less expensive than the damn Ferrari wires and you can get them in 8.5mm vs 7mm stock, you cant go wrong. |
JRV (Jrvall)
Member
Username: Jrvall
Post Number: 932
Registered: 11-2002
| | Posted on Friday, February 14, 2003 - 9:20 am: | |
Billy, is there some reason Magnacor can't make up a custom set ?
I send in my old sets and recieve back an almost identical fitting Magnacor set, although I haven't done a set for 348's, they work fine on TR's and Diablos.
I tend to agree with you on the performance end of the equation, in that I feel 'performance' gains would be negligible at best on street or track engines, even those considerably modded..
On the flip side though it is importantant to insure each system is optimized to allow the full potential to be realized. |
billy bob (Fatbillybob)
Junior Member
Username: Fatbillybob
Post Number: 203
Registered: 8-2002
| | Posted on Thursday, February 13, 2003 - 11:10 pm: | |
The 348 OEM wire is cavis made for ferrari. They fit the head the best and seal water the best. Magnecor suck in this regard. However, the cavis wire is just a cavis wire with fancy boot to fit the holes in the Ferrari valve cover. They are sold by the wire at about $200each! Magnecor probably are not any better, I.E. I notice no performance difference and I track my car. Magnecor is about 200 -300 for the whole set. So there you have it cheap= magnecor=same performance
expensive = ferrari= better physical fit for wet weather/dirt. |
JRV (Jrvall)
Member
Username: Jrvall
Post Number: 918
Registered: 11-2002
| | Posted on Thursday, February 13, 2003 - 10:04 am: | |
Jeff, my understanding is (if memory serves me correctly) is with the advent of electronic controllers, RFI - Radio 'Frequency Interference'- is/can be a real problem and is produced by solid core wires so they have gone by the wayside and been replaced by carbon core spiral wound wires that suppress potentially emmenating signals or static.
Yes I believe the magnacor site is a must read for any serious tuner. He writes at lenght to umask some of the mysteries of the spark system universe.
However, back to your original problem, as you describe it, as long as the factory wire is good, the spark can/will be blown out at the plug, not shunted in the wiring. The problem you described is 'thermal pressure' ie: Boost blowing out/shunting the spark, which is a sign the plugs are beyond their heat range of effiency. Porsche has had Turbo's and Turbo Boost problems in street cars since 1976, so very little about Turbo problems remain a mystery. |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 229
Registered: 7-2002
| | Posted on Thursday, February 13, 2003 - 6:16 am: | |
JRV. I think you ment EMI? Good article on the Magnecor site. I read it in it's entirety. I learned lots of good info. I recommend it as a good read for all tuners, home or pro.
http://www.magnecor.com/magnecor1/main.htm |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 227
Registered: 7-2002
| | Posted on Wednesday, February 12, 2003 - 9:58 pm: | |
Thanks, John. That's EXACTLY what I'm after. The car has plenty of power. |
John J Stecher (Jjstecher)
Member
Username: Jjstecher
Post Number: 353
Registered: 1-2002
| | Posted on Wednesday, February 12, 2003 - 8:08 pm: | |
Jeff I would go with the Magnacor wires for your 348, they are the best wires I have worked with on the american v8's I have built and the ones I currently use on my 348.
Wires will not make a performance difference at all, what they will do is allow your ignition system to transfer full power to the plugs. To me it made a differnce in my car cause at high RPMs the wire wasnt conducting full power to the plug. The best thing you will get from new plug wires is a smoother running engine from a more consistant spark being delivered. |
Paul Hill (348paul)
New member
Username: 348paul
Post Number: 43
Registered: 12-2002
| | Posted on Wednesday, February 12, 2003 - 5:11 pm: | |
Jeff,
Glad to hear you�re happy with the results. What sort of results are you getting on the dyno?
As for the grill - I have not had a problem with mine - They have 5 studs coming out of the back - you have to remove the air duct from inside the bonnet to gain access to them - they might be loose or it may be that is not sitting flush on the bonnet.
Paul
|
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 226
Registered: 7-2002
| | Posted on Wednesday, February 12, 2003 - 4:54 pm: | |
Paul,
Yes, I am delighted with the car. It is quite a thrill to drive, and I've been fortunate enough to drive more than a few. I feel lucky to have it.
BTW- Nice looking 348. How do you get the air grill in the front bonnet to lay flat? Mine is a bit wavy. |
Paul Hill (348paul)
New member
Username: 348paul
Post Number: 41
Registered: 12-2002
| | Posted on Wednesday, February 12, 2003 - 4:31 pm: | |
NGK list a C8E (with a 20 thou gap) for the F40 - I suppose you could call yours a similar set-up?? - I have not checked what the dimensions of that plug are!
I suppose Koenig would have had the same problems - would it be worth dropping them an email?
How is it all going Jeff? - Are you pleased!!
Paul
|
JRV (Jrvall)
Member
Username: Jrvall
Post Number: 906
Registered: 11-2002
| | Posted on Wednesday, February 12, 2003 - 1:45 pm: | |
>>When my car is on the dyno, under "high" boost, there is an occasional stumble, (ie miss). This is due to the additional fuel/air volume in the compression chamber and the plug failing to provide enough juice for the spark to jump the gap.<<
if that's in fact what's happening, it's called blowing a plug out....normally means a move to a colder or different type plug is in order. |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 225
Registered: 7-2002
| | Posted on Wednesday, February 12, 2003 - 1:34 pm: | |
Niether really. When my car is on the dyno, under "high" boost, there is an occasional stumble, (ie miss). This is due to the additional fuel/air volume in the compression chamber and the plug failing to provide enough juice for the spark to jump the gap. I am already using coil to plug ignition. My solution for the time being was to decrease the gap in the plugs. It has worked, however, wouldn't a better spark make more efficient and more complete fuel burn? I'm guessing so. I'd like to switch to denso iridium plugs and get a "hotter" wire. |
TomD (Tifosi)
Advanced Member
Username: Tifosi
Post Number: 2704
Registered: 9-2001
| | Posted on Wednesday, February 12, 2003 - 12:06 pm: | |
prob cost??? |
Rob Schermerhorn (Rexrcr)
Junior Member
Username: Rexrcr
Post Number: 228
Registered: 11-2002
| | Posted on Wednesday, February 12, 2003 - 11:35 am: | |
What's the downside of the factory wires? They seem to be high quality. Is it reliability, perfomance, power? |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 224
Registered: 7-2002
| | Posted on Wednesday, February 12, 2003 - 11:34 am: | |
Oh, well, OK then. I'll check with Motec and report back what they say. Did the wires on the TT Diablo make any difference? |
JRV (Jrvall)
Member
Username: Jrvall
Post Number: 905
Registered: 11-2002
| | Posted on Wednesday, February 12, 2003 - 11:16 am: | |
I don't think it's advisable to use solid core wires on computer controlled engines, because of RFI.
Motec might reccomend carbon core spiral wound wires of a high quality like magnacor, that's what I used on a TT Diablo, as well as many other engines. |
Jeff Edison (Euro308guy)
Junior Member
Username: Euro308guy
Post Number: 223
Registered: 7-2002
| | Posted on Wednesday, February 12, 2003 - 11:13 am: | |
Has anyone ever upgraded their plug wires on their 348? I have looked at mine closely. Even though they would appear to be a one piece wire with the extender molded to the wire itself, they actually do unplug. I'd like to replace them, (after I check with Motec of course for compatability), with a better conducting wire; say solid stainless steel core. I think it might help with better spark under boost conditions in my 348 TT. How about the F-40 guys? What is used there? |