Busa motor in car...need a little help

boeschbuilt

Registered
Hi guys,
Over the last 6 months or so I have been putting an 05 Busa motor in a Smart Car, I got it running today! :thumbsup: I had some problems and questions and was hoping I could find a little help here.

Question #1 When we first got it running one, maybe two of the injectors wasn't getting a pulse, My friend was over who is an expert foreign car mechanic, he said it was probably a bad computer that would make only one or two of the injectors not fire, I had another Busa motor laying around, this one an 07, I put that computer in the car and it cleaned the problem right up...My question is: Is this common? Is that other computer junk? if so, that really sucks!

Question #2 It seems to backfire on deceleration and shoot flames, Is this to be expected? It has a 4-2-1 header and a Magnaflow muffler.

Question #3 Do you guys think I need to get this thing tuned to really run right?

Question #4 Any thoughts on my intake design? Some one told me it needed to taper down towards the last cylinder, is this true?

there is a thread on the car here:
https://www.hayabusa.org/forum/random-thoughts/113765-my-hayabusa-powered-project-smartbusa.html

Thank you for any help!
Matt
 
A little bump for you

I don't know much but you may want to search for "pair/reed block off". On the bikes when you change the exhaust some people choose to do this mod to stop the backfiring. All though I never heard of flames shooting out before so this may not apply to your situation.

My guess is that you'll need to get the engine tuned. There's some free software out there that will allow you to flash the computer with a map if you're comfortable with that sort of thing. You can buy an interface from boost by smith if you need one.

Somebody with more knowledge will be by shortly.
 
hey, Matt! OMGoodness! What an excellent job on an excellent idea. And you could probably get someone to do some flow testing on an aftermarket intake to zero in a design for you, but I'm sure you've already thought about that. Very clean, very nice! Looks well engineered. Good job and looking forward to updates!! :bowdown: :thumbsup: :beerchug:
 
Hi guys,
Over the last 6 months or so I have been putting an 05 Busa motor in a Smart Car, I got it running today! :thumbsup: I had some problems and questions and was hoping I could find a little help here.

Question #1 When we first got it running one, maybe two of the injectors wasn't getting a pulse, My friend was over who is an expert foreign car mechanic, he said it was probably a bad computer that would make only one or two of the injectors not fire, I had another Busa motor laying around, this one an 07, I put that computer in the car and it cleaned the problem right up...My question is: Is this common? Is that other computer junk? if so, that really sucks!

Question #2 It seems to backfire on deceleration and shoot flames, Is this to be expected? It has a 4-2-1 header and a Magnaflow muffler.

Question #3 Do you guys think I need to get this thing tuned to really run right?

Question #4 Any thoughts on my intake design? Some one told me it needed to taper down towards the last cylinder, is this true?

there is a thread on the car here:
https://www.hayabusa.org/forum/random-thoughts/113765-my-hayabusa-powered-project-smartbusa.html

Thank you for any help!
Matt

I personally would have tried to utilize the stock airbox, or something close to it. Obviously space may have been a factor in that decision.

Backfiring is normal for these motors on deaccelaration. A good tune with a PC or reflash should clean that up. I would go with the reflash just becuase its cheaper. You could send the ecu to a tuner to have them reflash it for you.

Good luck, looks like a cool project.
 
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