I recently dyno'd my car ( '93 BPU Auto TT) and was not surprised to learn I was misfiring at high boost. I replaced my spark plugs with NGK 3300's gapped at .028 and hope it would help. The car runs much better throughout the whole power band but at idle it still get a small amount of detonation. It still sounds like a rough idle, like it might be running rich. Would a high flow intake help even out the air/fuel ratio? I have a drop-in K&N filter now and didn't think it would make a diff. but now I am wondering. If so, any suggestion on what kind to get or maybe an air box? Thanks a lot.
Brent

The 3330's are a colder plug and you have them gapped too low for a BPU car. The combination of a copper plug, heat range cooler and the low gap causes the idle to blurp, it has nothing to do with air/fuel ratios. Take the plugs out and regap them to .035" and see how that works.

Mark Tozer
'94 Supra 915HP

Or is the drop-in K&N sufficient? I like the air box on SupraStore but would like to get an honest opinion of how much diff it would make...I have heard many different things.
Thanks again!

Brent

A K&N drop in is fine.

quote:

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Originally posted by NotStock:
Or is the drop-in K&N sufficient? I like the air box on SupraStore but would like to get an honest opinion of how much diff it would make...I have heard many different things.
Thanks again!

Brent

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Mark Tozer
94 Supra 915HP
RPS T72
AEM Stand Alone
Black 6 Speed

I guess I will put my money elsewhere for now..

Brent

Yeah the only time you need to gap your plugs that low is if your running high boost. at stock gaps i would miss and im only bpu. I have mine gapped at .032-.035 now and its a happy camper and the idle is fine with no blurps. When you up wiht the big boys as far as power, then you will need to gap it smaller. SOme of them sacrifice idle for more HP. Also when you have more pressure in the cylinder, you get a bigger spark.