Low Revs Hunting On A Tuned 8v

[speedy 2]

My friends asked me to put this on here maybe we could find some help.

 

This is a 405 sri 8v engine running a race cam and TB's. They have been trying to set it up properly and managed to get it going good from 3000rpm to 8500 rpm. problem is it works like crap below that no matter the Mapping. Is this a common problem or they should be able to sort it out with the ECu?

[Dom9 2]

Is it a downsraft SRi head Speedy? If so, would be interested to hear their results following on from the recent topics!

 

If the mapping has been checked, double checked and triple checked then I guess it must be mechanical?! Could any of the butterflies be loose or not balanced etc?

 

Long time no speak, hope all is well over there!

[speedy 2]

Yes it is

 

Everything ok, just to much work and project cars going on at the moment that i had to put my 205 on hold again till june.

 

Thanks for your help.

[veloce200 3]

Yes it is

 

Everything ok, just to much work and project cars going on at the moment that i had to put my 205 on hold again till june.

 

Thanks for your help.

 

 

please tell the cam spec !!! if it runs to 8500 then it sounds fruity - will it just not run at all below 3000 - ie take no load - will it tickover?

[base-1 17]

If it's a really hot cam then it just will be crap very low down. You could improve it a bit but you can't beat physics with a good mapper, ECU and a laptop no matter how long you try for!

[speedy 2]

the mi16 injectors did not cope with these cams, he is currently running bigger injectors. The problem is he does not have the spec of the cam. They did set it up and it runs perfect above 3000 rpm but spits and refuses to work properly below that no matter if they advance or retard ingnition etc... so they finished putting the blame on the cam. It is a hill climb car so no real problem.