Spark Plug Heat ranges, what gains have you made?

[MoJo Risen]

I run a turbo car with a enhanced tune.
Boost is 16.5psi now from 14.1psi.

I have tried all variations of VP UNLEADED RACE fuel.

I find it difficult to see a performance difference in any as opposed to Costco fuel with VP octane booster.

I do have data that leans toward when I use VP C9 or MS101 AND BRACKET RACE THE CAR IS MORE CONSISTANT, EASIER TO DIAL.

I digress, my goal is to gain more from a colder plug than standard plug.

The NGK codest plug is 3 heat ranges colder than my stock plug.

I think it will be worth a tenth in my vehicle.

Thanks in advance for your input.

[curtis reed]

You think there is a tenth only from the plug change?



This may not be the best forum for a turbo charged question but there are a bunch of really smart guys on here.

[Adger Smith]

Enlighten me.
I'm not up on boost terms, but what is an enhanced tune?

[GTX JOHN]

I think there may be a small improvement in performance
if the engine is running in or on the edge of detonation.

[Jeff Stout]

All reason to go faster with correct plug on nitrous is having the wrong plug and torching electrode.

[MoJo Risen]

Originally Posted by Adger Smith

Enlighten me.
I'm not up on boost terms, but what is an enhanced tune?

Enhanced tune for my vehicle is, running ignition Timing right on the edge of pre ignition.

[MoJo Risen]

I also forgot to mention the colder plugs vs the standard plugs give me a full CC less combustion chamber volume.
This increases static combustion ratio, almost always positive.

I feel like stockers should be able to submit their own spark plugs to compliment the shape of their combustion chambers, just like people submitting their own piston variations in Stock.

Btw...
Has anybody been caught moving their piston pin offset/location in Stock yet?

[Stan Weiss]

A wrist pin offset normally is 0.060" to 0.080". When people reverse the wrist pin offset (do people still do this in stock?) this moves the pin center line 0.120" to 0.160" they may see a very small difference. Lets look at a 0.060" reverse and we a talking a little under 1 degree change in Piston TDC to crank journal TDC

Bore = 4.0 Stroke = 3.25 Rod Length = 5.7
Actual Piston Stroke 3.25019600382
Cylinder Volume 40.843168 CI 669.299602 cc
Engine Size 326.745340 CI 5354.396814 cc

Wrist Pin Offset = 0.06
Crank Angle Piston TDC -0.46932221356 Piston BDC 179.15635067565

Wrist Pin Offset = -0.06
Crank Angle Piston TDC 0.46932221356 Piston BDC 180.84364932435

Where you can really see a difference is with an inline motorcycle engine where the crank line has been moved 10 mm.

Stan

[MoJo Risen]

Originally Posted by Stan Weiss

A wrist pin offset normally is 0.060" to 0.080". When people reverse the wrist pin offset (do people still do this in stock?) this moves the pin center line 0.120" to 0.160" they may see a very small difference. Lets look at a 0.060" reverse and we a talking a little under 1 degree change in Piston TDC to crank journal TDC

Bore = 4.0 Stroke = 3.25 Rod Length = 5.7
Actual Piston Stroke 3.25019600382
Cylinder Volume 40.843168 CI 669.299602 cc
Engine Size 326.745340 CI 5354.396814 cc

Wrist Pin Offset = 0.06
Crank Angle Piston TDC -0.46932221356 Piston BDC 179.15635067565

Wrist Pin Offset = -0.06
Crank Angle Piston TDC 0.46932221356 Piston BDC 180.84364932435

Where you can really see a difference is with an inline motorcycle engine where the crank line has been moved 10 mm.

Stan

I honestly don't think NHRA ever checks wrist pin offset in Stock or any other class. It's a gray area. Maybe that's why nobody has ever been bounced for it.

Thank you for your math on the v8 engine offset.

The initial wrist pin offset was to make engines quieter in early days, that particilar offset was the opposite of centerline direction that the offset used to gain leverage and ultimately Horsepower.

It's always been a gray area and until someone comes forward with "they've been bounced for this, then anything goes in my opinion.

[Terry Cain]

Originally Posted by MoJo Risen

I honestly don't think NHRA ever checks wrist pin offset in Stock or any other class. It's a gray area. Maybe that's why nobody has ever been bounced for it.

Thank you for your math on the v8 engine offset.

The initial wrist pin offset was to make engines quieter in early days, that particilar offset was the opposite of centerline direction that the offset used to gain leverage and ultimately Horsepower.

It's always been a gray area and until someone comes forward with "they've been bounced for this, then anything goes in my opinion.

NHRA DOES check wrist pin location. Ask David Walther or Tom West. 1972 winners of div race at Muncie, IN until getting tossed for have stocker pistons in backwards. It's all been tried. Nothing new.