993 Cup Spark Plugs
993 Cup Spark Plugs
12-02-2001, 12:00 AM
#5
RL Technical Advisor
JM:
Those Bosch plugs, FR6DLC or FR5DTC will both fit, but I would use the FR5 DTC (triple electrode copper) for everything except competition. The "6"s are too warm for a Cup car, IMHO.
Boshc makes a race plug for these engines but they are really cold and would be unsuitable for street or DE use.
Those Bosch plugs, FR6DLC or FR5DTC will both fit, but I would use the FR5 DTC (triple electrode copper) for everything except competition. The "6"s are too warm for a Cup car, IMHO.
Boshc makes a race plug for these engines but they are really cold and would be unsuitable for street or DE use.
12-02-2001, 12:28 AM
#6
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Steve,
Thanks for chipping in and pardon my ignorance but can you explain or point me to what you mean by "too hot"? Also, my car is only for track use as its not street legal so should I get the FR5 DTC for "play" and the Bosch when I actually race it?
TIA, your knowledge is greatly appreciated as always
JM
Thanks for chipping in and pardon my ignorance but can you explain or point me to what you mean by "too hot"? Also, my car is only for track use as its not street legal so should I get the FR5 DTC for "play" and the Bosch when I actually race it?
TIA, your knowledge is greatly appreciated as always
JM
12-02-2001, 04:26 AM
#7
RL Technical Advisor
Originally posted by Jean-Marc:
<STRONG>Steve,
Thanks for chipping in and pardon my ignorance but can you explain or point me to what you mean by "too hot"? Also, my car is only for track use as its not street legal so should I get the FR5 DTC for "play" and the Bosch when I actually race it?
TIA, your knowledge is greatly appreciated as always
JM</STRONG>
<STRONG>Steve,
Thanks for chipping in and pardon my ignorance but can you explain or point me to what you mean by "too hot"? Also, my car is only for track use as its not street legal so should I get the FR5 DTC for "play" and the Bosch when I actually race it?
TIA, your knowledge is greatly appreciated as always
JM</STRONG>
The difference between a "hot" plug & a "cold" one is the operating temperature at the tip of the center electrode. Cold plugs operate at lower temps than hot ones and in air-cooled engines, its VERY important not to use a plug that is too hot for track use.
Using a plug that is too hot for the cylinder condtions can create detonation and subsequently, pre-ignition as the tip of the plug glows and will ignite the fuel/air mixture prematurely. Holes in pistons follows thereafter.
The '5' rating of these plugs is just fine for DE use and if you do any racing, then I would use the Bosch race plug. Your 315 Hp Cup engine is not so high-strung that the RSR plugs are needed all the time.
Race plugs (RSR ones) will be rather cold and the engine should never be allowed to idle to prevent fouling. Race plugs do not use extended tips (anti-foul measures) and have short ceramic center insulators.
Questions?
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12-02-2001, 10:14 AM
#8
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Lots of questions.....
1) Apparently, the FR5DTC is identical to the street car's. Is that true?
2) What can I expect from using the FR6DLC in competition? More HP, quicker response?
Sounds like a major PITA to remove plugs between driver's ed/track days and race...
3) What is the best "compromise" for someone like me who does this for fun only?
4) Where should I buy the plugs that I will get? Of course, if you sell parts I'll buy from you !!!
5)How often should plugs be changed in a race car?
TIA
JM
1) Apparently, the FR5DTC is identical to the street car's. Is that true?
2) What can I expect from using the FR6DLC in competition? More HP, quicker response?
Sounds like a major PITA to remove plugs between driver's ed/track days and race...
3) What is the best "compromise" for someone like me who does this for fun only?
4) Where should I buy the plugs that I will get? Of course, if you sell parts I'll buy from you !!!
5)How often should plugs be changed in a race car?
TIA
JM
12-02-2001, 01:31 PM
#9
RL Technical Advisor
JM:
Here goes,......
1) The FR5DTC is the same one as the proper street plug.
2) The FR6DLC is too hot for DE or track use. I would not recommend that one. Remember, the number in the series is the heat range and Bosch plugs get hotter as the number increases. The difference between a 5 and a 6 is significant.
3) It IS a PITA to change them,.....welcome to the world of race cars. I would use the FR5DTC for everything except full-on racing, in your Cup car. Further, I would perform a few plug cuts to confirm that everything is OK inside the engine at RPM and under load. You might need an experienced and qualified person to "read" your plugs when you do this.
I will post "How to perform a proper plug cut" on my website today.
4) These are common plugs and although I would be pleased to provide them, IMHO they would be cheaper from one of those big discounters like Vertex to save you money. I always hate to send business away but my customer's interests need to come before mine...........
5) You should change them when they start to look worn or you need a different heat range.
These triple-electrode plugs really last a long time in cars that have excellent mixture control and use unleaded gas.
The RSR's need leaded race gas and under those conditions would be changed every few races.
Hope this helps,
Here goes,......
1) The FR5DTC is the same one as the proper street plug.
2) The FR6DLC is too hot for DE or track use. I would not recommend that one. Remember, the number in the series is the heat range and Bosch plugs get hotter as the number increases. The difference between a 5 and a 6 is significant.
3) It IS a PITA to change them,.....welcome to the world of race cars. I would use the FR5DTC for everything except full-on racing, in your Cup car. Further, I would perform a few plug cuts to confirm that everything is OK inside the engine at RPM and under load. You might need an experienced and qualified person to "read" your plugs when you do this.
I will post "How to perform a proper plug cut" on my website today.
4) These are common plugs and although I would be pleased to provide them, IMHO they would be cheaper from one of those big discounters like Vertex to save you money. I always hate to send business away but my customer's interests need to come before mine...........
5) You should change them when they start to look worn or you need a different heat range.
These triple-electrode plugs really last a long time in cars that have excellent mixture control and use unleaded gas.
The RSR's need leaded race gas and under those conditions would be changed every few races.
Hope this helps,
12-02-2001, 02:35 PM
#11
RL Technical Advisor
Originally posted by Jean-Marc:
<STRONG>Thank you sir,
I GOT it. Can't wait to read your web site. I'm off to Japan tonight and will read it from there!
JM</STRONG>
<STRONG>Thank you sir,
I GOT it. Can't wait to read your web site. I'm off to Japan tonight and will read it from there!
JM</STRONG>
You'll find plug cut procedures and instructions on Our Technical Reference information page. This is accessed from:
Technical Information and Reference
I've just posted this information and will be adding more all week.
