PLEASE NO : Why would you bother with a B3 as i have already got all the crap from other forums
The Mazda B3 engine is a smaller Block of the B6 and BP both of which can come with a turbo depending on model.
The B3 which i will talk about here is a 4cyl 1.3L 8 valve SOHC, you wont find many of these modified around the Streets but there is a few, i will explain how i have made some gains from a few mods to the car, all these are done on a budget.
Step 1: Getting better airflow into the manifold.
This is a hard thing for the carby cars i have modded my airbox to draw air from the front of the car, in my 121 i have a 4" gap between the body and the radiator of the car so i made up some pipes to route down to there its that hidden that you cant see it anymore, this dose not make the car much faster and just gives a cooler airflow from the front of the car it used to draw air from the front of the motor behind the drivers head light.
Step 2: upgrading the exhaust system. (yes even these cars sound better with good system)
mine i have a 2.25" system with a 4" cannon fitted to the rear, i was lucky and already had a 2.25" Cat and extractors on the car which didnt make sense to me as the old pipes from the cat back were only 1.5" which would have been putting a fair bit of presure on the system.
to tell you how loud this will make the car is way too hard so i have made a short vid on the sound i am getting (Warning this is not legal at all and if you drive with just this setup on your car you will face the police)
heres the vid
those are not my number plates too old ones put on the car.
This kind of system will require a resinator or hotdog as some call them, this will bring it down to NSW laws for max dB from an exhaust system, it is 90dB for nsw or 96dB just depend who dose it EPA will test for 96 and the RTA and Police will test for 90dB which is required before it gets sent for EPA.
This system is off the car untill i can get the hotdog fitted which will be a few weeks away.
Benifits from this system for me are higher flowing air = more power not heaps but enough to spin wheels from 1st to 3rd, better sounds i had a lancer and skyline pull up next to me both thought they had nice sounding cars then i just give it a few bursts of RPM arround 4000 and they didnt bother anymore
ok im not braging here and this is a real good mod but will not make your car a super car to beat skylines and the sorts, this is just to show some ppl out there that these things can be done and will provide benifits to you and your car.
the now free flowing B3 idles arround 1100RPM and runs 98ron fule i havent done any dyno tests yet but i suspect about 10-20 extra HP from the car, not much but for this little 750Kg car it brings the Power to weight ratio up.
Step 3: this is a little bit of a harder thing to work with, Its the Clutch, i recomend you cange this due to the extra power you will be producing, i have just done mine and its was so bad i had to change the flywheel, if you can get a replacement box that will make it easier for you.
i wont go too much into this but if you have never changed a GB before then you may want to get someone to help you out, they are not that easy to replace local stores arround my area wanted anywhere from 400 to 1200 to replace the clutch, i done mine for just under 200 with all the parts needed.
General tune for the car.
on the carby motors they are suspect to a tapping noise from the rockers, this is common in the B motors from Mazda. you cant really do much about it other then replace the valves and rocker arms, i have not done this yet and it can be heard from the vid i posted up top.
use high grade engine oil i use 5w-30 this i have found runs well in the car, also upgrade the GB oil and use a treatment which you can get from auto stores for arround $7 i upgraded to high preformace oils and lubes and the car just loves it.
get a better thermostat this is critical as stock ones are crap and open way too early.
if you can get your rocker cover sandblasted and a nice look like this http://i47.photobuck...21/P4120354.jpg
you can set the timing advanced to about 10* my car seemed to like it if i moved it back it didnt have the power i was looking for, the valve clearance must be set perfect for the perfect power for the car its all hit and miss you need to spend a fair amount of time working on these 2 things to get the right tune from your car.
Carbys will need a clean often you can buy carby cleaner from auto parts store which will get rid of any gunk in the carby and will give it a new lease of life.
Rocker cover gasket: these are not real good you could get a replacement but i found something better its a gasket glue sort of thing its a copper based tube and will seal any area that has oil and water near it i used this with my gasket from the rockercover for a better seal it is a red coper color auto parts stores have these and will advise you on what you need.
Thats about all i can think of right now ill update as i do more work or if you have other things you know of let me know and ill add them.
if you have questions ask away i will do my best to help you out.
Edited by Racemania, 29 May 2008 - 08:11 AM.