I did a d15b vtec swap early this year. I did the initial swap myself, but eventually ended up taking it to the mechanic due to a warped head. Everything on it was replaced and to spec. But its very slow. Someone told me it may be a slipping clutch, and thats about all I can think of at this point. It runs fine, but even getting past 70mph is a struggle, like the engine is running fast, but I'm only going normal speeds. Its not a race car by any means, but its supposed to be 130 hp and it doesn't feel like it. I am using my same tranny from my old d15b1, 4spd manual. I know its not the greatest, but I have no idea if the clutch or flywheel or anything has ever even been changed. Its an 88 civic hatch std. If anyone has had similar problems or info I'd like to know. Thanks

 

if your clutch is bad, it may stop grabbing all together, so when you try to accelerate, your engine rpms go up but your speed stays relatively the same. I bet you do have a bad clutch, given your description. clutches only last about 60k miles or so.. even with light driving.

 

when you accelerate, does your engine rev high really fast but you don't go anywhere? or does your car take a long time to get the revs up and accelerate?

 

U need to change both clutch and tranny. That trans has extremely LONG gears

 

Yeah, I agree. Plus the tranny has 147,000 miles on it. It seems to shift fine, maybe a little tough at times. I just got a stage 3 clutch and flywheel. Ill keep you posted. I just got my internet back, sorry about the long wait.

Yes! My engine sounds awesome, and I just have a stock exhaust. Itll sound and feel like it running fast like Im going 100+ miles an hour, when really Im just going 60mph. And yes it takes forever, its embarassing almost. The engines in tip top shape. I really want to replace the clutch soon, but school and work are a pain. Ill keep you posted.