not planning any major mods - aiming for 200whp maybe,

trying to construct a solid 2.0VTEC setup in an '83 Prelude...

would best exhaust size be 2.25in? or more?

which factory cat. converter flows best? any experiences?

TIA,

T..

 

the b20 really needs to flow to unleash all that hp/torque it has. so let the thing breathe. 2.5" would be good. especially if you go b20vtec. dont want to restrict valuable power. as far cat, try a magnaflow. this is what my plan is. inexpensive..very much so compared to other cats. 2.5"..straight through design. good stuff.

 

Yep, I think 2.5" is pretty damn perfect for that motor.

 

i would agree on the exhaust size, what block are you running? the stock prelude B20?

 

confused, are you asking about B20 (prelude 88-90 engine) or B20(CRvtech)? Ironically they have the same badge number in the beginning. either way the 2.5 magnaflow is prolly the best bet for your money and has the best dyno'd results. if you are asking about the B20 lude engine there is a <U> GREAT </U> resource page and person that could answer any/all questions about that setup and vtech conversion for that setup. email tom@ludespeed.com if it is the latter. he is the first guy to make a vtech convertion kit for the 88-90 lude engine also makes a turbo kit for this generation. -cheers

 

2.5" is sufficient

I used 2.5" custom piping to an N1 on my previous B20 setup. I took a chance and stepped up to a Thermal 3" catback used for FI purposes and acutally made a significant amount of HP on the dyno compared to the old 2.5". I dont suggest it though unless you are well over 200whp.

GLUCK

 

wow, now that is interesting. i haven't heard of anyone taking that chance. obviously you stayed with a 2.5 collector on the header right? and 2.5" cat? you jus bolted the 3" thermal catback on and saw dyno improvements?

 

no, just the boring old B20B CRV type, none of these exotic B20A prelude blocks for me...

(my car came original with a 1.8l SOHC 12 Valve Carbie fed 120HP monster...)

2.5in seemed to be the most logical size to me,

thanks for the confirmation

t..

 

how about going with a 3" full catback exhaust instead of a 2.5"? im plan on going with a 3" with my b20v but some of my friends suggest going with 2.5" since i'm not turbo.. wat do you guys suggest?

203whp with 143ft with stock cx exhaust..haha

 

anything past the collector is just a restriction. Sure there might not be much difference but 3" is less of a restriction than 2.5" so there is no way you would lose power by going bigger.