Why lengthen plug reach increasing turbo boost?

[Mark300zx]

Answers on a postcard please

[Mr2Mike]

Could we have a clearer question first please?

Are you asking why increasing the plug reach increases boost, or why you have to increase plug reach if boost is increased, or something else?

[deltaf]

Not heard of this before. Thought the idea was to run the coldest possible plug that wont foul under normal driving conditions, for the road at least.
Gives the best power output without overheating the plug.
Dont see that a longer reach plug will accoplish much, short of overheating due to the longer heat path...?
Oh and a possible coming together with a nice shiney new piston perhaps?
Feel free to correct me tho..

[kevinday]

deltaf said: Oh and a possible coming together with a nice shiney new piston perhaps?

This was my immediate thought as well.

[plipton]

kevinday said:

deltaf said: Oh and a possible coming together with a nice shiney new piston perhaps?

This was my immediate thought as well.

Indeed - if it doesn't hit the piston it might increase the compression a smidgen but not boost (you need something like a Dawes Device for that).

I would suggest this is not a good idea (wrong plug reach, that is) as the head is designed to take a specific plug size.

[boosted ls1]

I think the question relates to projected nose type spark plugs as used in my 2 stroke bike engines.

The idea is to have the electrode projecting further into the centre of the combustion chamber. I used to do this on turbocharged RV8's and used NGK BP8EGV if memory serves me correctly. You can still achieve the same heat range as that relates more to the length of the insulator.