20b questions
 

I own a 91 cosmo with 64,000km on it, at what point will i need to rebuild my motor, and will there be any warning signs of a rebuild being needed?The car came with a boost controller, and a turbo timer ect.. but the cars exhaust is stock and quite restrictive. Would the motor have a shortened life because of the higher boost on an otherwise stock setup?

The turbo timer the car came with also reads the A/F, im guessing that means air/fuel.. when the car is at a stop it read 20.0 with a green led on. When i give it 1/2-2/3 throttle it drops to 11-14 with a red-orange led

Am i getting worried over nothing or is there somthing to this?

Would a compression test tell me how much life is left in my motor? what kind of numbers should i get?
I know these questions prob sound stupid :) but im still new to this so any help is much appreciated

Do a compression check for piece of mind. The raised boost level whould shorten engine life but on a 20b its not going to hurt it much if your using the stock twins. Hope you have a boost gauge though.

If it doesn't have a problem starting and idels fine I would assume its still with in spec.

if it's not broken, don't fix nothin'. :) strict maintenance and common sense can go a long way for engine longevity.

if i'm reading between the lines correctly, you're not interested in major modifications, so i would recommend you get a decent exhaust system fashioned and do some research to see if the Cosmo has a similar ECU to the FD, in which case you're going to have to get something aid in tuning for the slight boost increase it will bring.

if you're serious about this, i would try contacting the users Evil Aviator or DRMH. they are probably the best 20B resources i can think of readily.

Yeah Evil is pretty damn good ......havent seen him around much lately though , other than that increased boost should`t shorten life dramaticaly (of course assuming it wasn`t raised heavily) do a compression test and you should be fine ,I wouldnt worry much about the engine usually they dont boost them that much and they have that VERY restrictive exhaust housing (stock on 20B) so usually IF they play around with them , its just mild stuff , unless someone opened the exhaust ports , then they could have done major upgrades

Thanks for the quick replies, this forum kicks ass :score:

What should the compression be on each rotor?

Im cautious about taking it to the mazda dealership here, the mechanic i spoke with had never heard of a 20b or a cosmo. Any good tuning shops in BC :dunno:

If everythin checks out fine i would like to run the car around 350whp. Would this be possible with exhaust, intercooler, and proper tuning?

thanks

These engines run 300hp stock, dont they?
350hp wont be a problem.

stock, i believe it's 280 at the flywheel, so just take it from there. not really sure what the top range of your turbos are, but if (very BIG "if") they are capable of 350 to the wheels they will probably be well out of efficiency range. confirm that with a more knowledgable source though. i just thought it's something you may want to consider before setting HP goals.