Fuel pressure and plug gap question........

[irockwithdirt]

Slowly modifying my 84 hotair..........I believe the car has an unknown history..........someone put alot of money in it..........then someone tore it up and let it go to hell. Just finished installing a 340 fuel pump, hotwire kit, new filter, and acufab adjustable regulator. Car has a 87 coil with new MSD wires and plaitnium plugs. Unknown turbo (looks new) W/ adjustable wastegate valve. Don't have my new boost gauge installed yet so I'm not sure what the boost is set at. Flowmaster exhaust...........all else unknown modifications. For now where is it safe to set my fuel pressure and gap my plugs till I can work thru this? From reading posts have plugs gaped at .35 , old ones were at .50 . Is 40-42 safe for the fuel pressure? Thanks, Kevin

 

[Chuck Leeper]

Plugz??

2 thots come to mind.
1. DO NOT play until the boost gauge is in and working.
2. Do not use platinum plugs...They've been found to cause problems in turbo applications. .035 is a bit wide. More like .032, and at high boost, even smaller works well.
I use only AC 43RTS @ .032 on a iron headed streeter.
I use AC 42RTS at .030 at the track " " engine.
The FP in that area should be a good start.

 

[irockwithdirt]

Not playing at all.... more like grandma driving :-P ....car has been sitting and not running.......trying to sort things out........car is a disaster. Thanks.......should I change the plugs right away (damn that #6 plug sucked)? Above all else no scary engine noises, plugs looked good, oil looks good......... think my next thing to change after it is fairly running fairly decent will be the timing chain and HV oil pump..........that sound right? Any experiences with edelbrock's timing chains?

 

[turbo6x2]

I run NGK-UR5 but my mods are pretty heavy. The Auto lites actually work a bit better from my testing compared to the delcos in the hot air. You could try the NGK-ur5 gapped at 032 these seem to work really well for hotter applications. But for your build try the auto lite 24 gapped about the same and see what you get. Pretty inexpensive the 23's may even work better. Unfortunately every car is a bit different depending on the build and hot airs don't necessary like what an intercooled would. Believe me I know we have both. What works on the intercooled 87, doesn't do jack for my hot air....As far as fuel pressure you really need to know your 02 readings, a computer would be wise right up there with the boost guage. You really need to know what you running o2 wise before playing. It saves a lot in the long run. Turbo link works on the 84/85 ecm for this. Just my two cents. The hot airs like it rich compared to the intercooled o2 reading just so you are aware.
Take care and this wasn't by any means a flame against anyone, just the hot air and intercooled are different breeds, especially when you have both. Invest in a notebook to take down readings this helps keep everything straight as well.

 

[turbowrenchhead]

What happens when you slap a i/c on a hot-air. Do they react the same as the 86-87's then?

 

[turbo6x2]

I'm sure it would change the running due to the fact your changing the set up, comparable to running alcohol or propane....