Smoke Screw?

[CAROLINA CUMMINS]

Howdy,





I was wondering, since I don't have any guages (Uh-Oh)

if I could turn up my smoke screw a little bit. I was reading some

instructions on this(smoke screw) and it said 2 CW turns of the smoke screw would raise EGT 75 degrees. If I turned it 1 turn would I be okay(about +37 deg)

I have a K&N and A 4 inch straight pipe(stock downpipe),also

it says that to put some Loctite thread sealant with teflon on the little plug, is that regular loctite or something else? what else could be used for that.







Thanks



Steve

 

[Midnite]

Well, I think you could turn the smoke screw a couple of turns without any EGT problems at all. But that's because the smoke screw is used to modify fuel delivery under pre-boost conditions--ie, you're at a stoplight which just turned green, you roll into the throttle, and the turbo hasn't spooled up yet.



What turning up the smoke screw will do for you is increase driveability in stop and go type driving. At least it did for me.



Don't go overboard though--you might just want to try it in half-turn increments, and do a test drive after each one, paying attention to low-boost driveability, and smoke.



Hopefully someone more knowledgeable will jump in here, but I believe the star wheel and the full-power screw are the ones that have the potential of pushing your EGT to unsafe limits.



Just to make sure we're talking about the same "smoke screw", you mean the hex screw under the small cap on the top of the injection pump, right?



Mike

 

[ETOBICOKE]

Teflon Dope

The Loctite product you refer to is teflon pipe dope (sealant)looks like bird poop and comes in a squeeze tube, it's not the same as the type used to lock screws. I don't like that product as it tends to be hard to disaasemble after a few years, pink or orange teflon tape is better. I use Loctite 545 liquid pipe dope now for most threaded pipe joints and Master's Metalic for high heat applications.



Neil

 

[BushWakr - RIP]

I kept putting my little cap back on, taking it off, on/off arghhhh...

I "filed it" in the tool box for future reference. It don't make any difference to things so I'd say, store it.

The smoke screw will adjust your "launch" feel. Say, the first 30 -50 feet or so. After that its done.

The star wheel affects mileage and temps, it does all its work up to around 12 psi boost then it does nothing further.

The full fuel affects temps, especially at the upper end. It will distribute fuel across the boost/RPM band with a higher portion of the increased fueling directed to the lower/mid range.

Last, the diaphram (AFC) will affect EGT's as well since it changes the 'rate' of fueling, or, how fast max fueling comes on. I think this about covers it.

Oh ya, lets not forget 'nozzles' they can really help raise your temps... more fuel=more power=more EGT's

So, if you want to improve your 'launch' feel you can twist the smoke screw in 1/4 turns till you like the launch or can't stand the launch smoke.



If I got any of this wrong, please fix me up.



bob.