i have a 89 prelude 5spd b21a1
im looking to see how cheaply i can obtain 220hp on a budget, and please dont tell me to swap a different b series or a h22, i want to know what cheap performance mods there are for the motor i have.

thanks
pat

 

There's no cheap way to obtain that number. If you wanna boost it to get that number reinforcing the block is needed for longevity and you'll have to find someone to custom build a turbo manifold or find someone who already had it done and see if they're selling so cheap is out the window, you wanna do an na build its gonna cost a good amount of cash trying to get there and by then you could've boosted it for cheaper than that. That's why everyone swaps it out. The prelude bastard series need a good amount of custom work for anything to fit. I know you didn't want to hear it but the cheapest is going to be an h series. B series is fun and peppy, feels awesome on the canyon runs a long with that 4ws. Cheap and prelude just don't come together man. Grab yourself a civic for a bit of ease of cheaper parts.

 

IHE and weight reduction is cheap but the gains are not very high

 

1) the b21 only came in 90-91. So if your chassis is in fact an 89 and it does in fact have a b21, someone swapped it in, which was incredibly stupid
2) the b21 is a throwaway motor. don't bother modifying it with anything besides bolt-ons
3) the only way to get over 170hp from a 3g motor is a rediculous engine build with high compression and running race gas or e8, or turbo it. And yes, there are still people that make quality turbo manifolds for 3g motors
4) 3g blocks are strong as hell. there is no need to reinforce the block in any way. Pistons and rods however are a different story.

 

I didnt know they were that strong. Can a b20a take a decent amount of boost? Wanna push it before swapping an H series in.

 

I have a b20a block in my 3g right now making 410hp/385tq, daily driven daily abused. Bored 2.5mm oversize, NOT sleeved. OEM h23a1 rods, JE forged pistons. B21 head and intake manifold, b21 exhaust cam, b18a intake came modded to fit, supertech h22 valve springs, ACL race bearings, ARP head studs, Cometic HG, 24psi from a T3.

The question of what a b20a can handle for power all depends on what parts you install. As I mentioned above, the block itself is incredibly strong. The pistons are the weakest point, and break like clockwork once you exceed ~235tq no matter how conservatively or aggressively it's tuned. Rods and HG are second weakest point.

 

Was just going to get a cheap ebay kit and run it till it blows. Just wanted to see how much power I can get out of stock block. So keeping tq numbers under 235 seems to be the max. Thanks moto. Want it to last just a bit longer till my 5th gen build is complete.