well i have a 90 civic hatch si, converted to obd1, no engine lights, clean swap etc, i am running the stock si exhaust and a sir intake box with k&n filter, i lose to a stock 5.0 by about 2 cars and got raped by a zc crx, i can hear the vtec crossover and it pulls all the way, is it because the exhaust? but can exhaust really hold a car back that much? thanks, sean

 

Well..the stock 5.0 you should lose to..but you should be pretty close to the crx. You say its running fine? The exhaust on the Si shouldnt be that bad, so it must be something else. Maybe just a beat motor? How many miles on the motor/any noises?

 

no unnatural noises, runs really good, very smooth idle, no idea on the milage of the engine, i was able to beat a 00 civic with the d16y8 pretty damn bad but i dont know...well this week i am going to toss on my 2.5 exhaust and see if it makes any difference

 

i got a full si catback on my built b16 91 hatch...runs fine no problems at all...i know i could definetely benefit from some better piping but its not like its holding me back at all