quote:

---

Originally posted by 02BestSSyet:
The SLP Cold-Air Induction Package (#21033) increases the amount of air entering the engine. One effect, but not the only, is a higher compression ratio.

In the world of spark plugs, a "cold" spark plug is better for high compression engines. NGK offers the TR6 and TR6-IX Irudium spark plug for such engines in place of the TR55/TR55-IX.

Is changing to the TR6-IX Iridium plug a good idea? Logical thinking says yes but asking someone with experience is usually better.

By the way, the cold-air induction kit HAS NOT been installed yet. Thanks for the advice.

---

Okay.....I'm going to get picky here!!

Any changes to the induction system will not have an impact on or change the "compression ratio" of an engine. This is strictly a function of the mechanical design of an engine and is the change in the cylinder volume from bottom dead centre (BDC) to top dead centre TDC). A change in compression ratio can be made by stroking an engine or changes to the combustion chamber volume (i.e.: milling a head).

A change in the induction system can change the "pressure" in a cylinder at TDC. The better an engine breathes the more air it can bring into the cylinder. Also, the colder the intake charge....the more air/oxygen is brought into the cylinder. The amount of air in the cylinder at BDC will change the "pressure" in the combustion chamber at TDC. The amount of air also determines the amount of fuel resulting in more power.

Having said all that I have had the SLP CAI on my car since last summer and I have had no problems with stock heat range spark plugs.
 

---

Posted by 02BestSSyet (Member # 1998) on :
 

quote:

---

Originally posted by Bill Mason:

quote:

---

Originally posted by 02BestSSyet:
The SLP Cold-Air Induction Package (#21033) increases the amount of air entering the engine. One effect, but not the only, is a higher compression ratio.

In the world of spark plugs, a "cold" spark plug is better for high compression engines. NGK offers the TR6 and TR6-IX Irudium spark plug for such engines in place of the TR55/TR55-IX.

Is changing to the TR6-IX Iridium plug a good idea? Logical thinking says yes but asking someone with experience is usually better.

By the way, the cold-air induction kit HAS NOT been installed yet. Thanks for the advice.

---

Okay.....I'm going to get picky here!!

Any changes to the induction system will not have an impact on or change the "compression ratio" of an engine. This is strictly a function of the mechanical design of an engine and is the change in the cylinder volume from bottom dead centre (BDC) to top dead centre TDC). A change in compression ratio can be made by stroking an engine or changes to the combustion chamber volume (i.e.: milling a head).

A change in the induction system can change the "pressure" in a cylinder at TDC. The better an engine breathes the more air it can bring into the cylinder. Also, the colder the intake charge....the more air/oxygen is brought into the cylinder. The amount of air in the cylinder at BDC will change the "pressure" in the combustion chamber at TDC. The amount of air also determines the amount of fuel resulting in more power.

Having said all that I have had the SLP CAI on my car since last summer and I have had no problems with stock heat range spark plugs.

---

I didn't phrase that right. I meant to say the "compression" (pressure) will increase when more air than normal is forced into the engine. You can read the link below to better understand where my question originated from: http://www.ngksparkplugs.com/techinfo/spark_plugs/overviewp4.asp?nav=31000&country=US.

Thanks for letting me know that it's okay to use the stock plugs with a CAI kit. Much appreciated
 

---

Posted by Scott Chab (Member # 174) on :
 

quote:

---

Originally posted by 02BestSSyet:
I didn't phrase that right. I meant to say the "compression" (pressure) will increase when more air than normal is forced into the engine.

---

UBB.classic™ 6.7.0