Alright guys (and gals), I got a problem.

My little a14 has a has developed a terrible chugging when idling. I don't know what it is, but it is starting to annoy me.

I have been through all the usual checks- mixtures, plugs, leads, timing. Everything is perfect. It only does it when idling, when I accelerate and the s/c starts boosting it goes like the clappers. Pull up at the next set of lights and chug chug chug...

Maybe a bent needle in the SU- anyone have any knowledge??

Sorry I cant help ya on this at all, but I am curious about the engine and setup you have. What kind of blower did you use and is it pretty much streetable for regular driving? What did you do to the engine to prep for the blower? Was it expensive to do? I am looking at options to get my little coupe moving better but do want to drive it too.

Thanks

Hey Salty,
All the usual stuff- forged pistons, hardened valves, springs etc. I wanted reliabilty as well as performance. Blower is off the 4agze toyota motor. Runs 5psi at 2500 rpm and 10 psi at 6000 rpm.

Relatively cheap, but I put all the fruit on to ensure longevity of the motor (water injection, big radiator etc). Very driveable on the street (in the dry) and isn't too bad on the track either...

Quote:

what???, i was under the belief that super chargers make the same boost irrespective of revs???

my a12 twin turbo made 10psi at 2500 and 10psi at 6000, that sounds more like a supercharger , but i wont say thats the benefit of twin turbo cause i only have a 4cyl motor so it doesnt work

getting a fair bit off topic, sorry, but i was watching a performace video where they were building a quad turbo V8, someone should tell them it wont work

blown 1400 you didnt really give an accurate description of your problem, what is chugging??? are the revs changing or roaming?, or is there coughing or shaking of the car? or is it just making funny noises

hey blown a14 i finally got my s/c yesterday, very cool cant wait to get it on the engine, i ran it on a electric motor 1500rpm and i cant believe the amount of ir it makes, its the 4agze same as urs.hurry up and get some fotos up u been promisin for ages i wanna see how ur piping is set up as the inlet/outlets are opposite to what i though so its all backwards gotta run carby from the left hand side etc.

Hey kegs, sorry about the photos. I tried to catch up with Lobster on the weekend, but his phone was off. I will give him a call once i have finished here. I will also try and get up to Sydney over the next few weekends and come by so you can have a look...

In regards to the chugging, it sounds like a v8 running a huge cam. Quite a bit of engine shake and almost throbby under light acceleration. Smooths out instantly once I accelerate harder. Could it be the cam? I have done about 1000kms since build and ran it in on the dyno. Any thoughts that a cam would change profile after about 1000kms and dyno run-in??

Its not ch uging because of flooding at idle is it? Just a thought.

does it do it with the blower clutch disenguaged?
What size is your crank pulley?
Once I get a WOF on my sunny Ill be fitting the sc14 to my a14.

What carb are you running? When I had the a12/Hitachi in my car it had the same problem all of a sudden. Took out the air bleeds(gotta take off the carb top to do this if I remember correctly), after careful examination, a tiny piece of gasket was lodged in the small hole. When it was removed, the engine purred once again!
Also, check your distributer advance isn't loose/sticky or something.
When in doubt, I always go back to the basics; check for steady vaccum and do a compression check.
Are you running big valve springs? Double ones? May help to pull the valve cover and check to make sure the lobes aren't chasing the base circle.....going flat.
Hope this helps a little.
-Donnie

Oh man, now I am really interested in seeing a photo of this set-up as well. What kind of HP are you getting outa the blower A14? In hind site would you have gone with anything different? A15? other? This sounds awesome, well once you sort out the chugging thing, which you will.