Hello everyone,

I am considering supercharging my AP1 with an HKS Supercharger. I currently have a built head with Ferrea dual valve springs, titanium retainers and BC Stage 2 cams, tuned on AEM Infinity. 4.44 gears in the rear. 47K miles. Car runs healthy with good compression across the cylinders.
I'm not looking for crazy power or anything hence the HKS kit. The stage 2 cams can put a bit of extra strain on everything else so I've upgraded the timing and oil pump chains with Toda and have a Billman X TCT.
Should I be concerned about adding a Supercharger to this setup or as long as I keep my hp goals modest I should be fine? I just want a bump in power with reliability.
I've already considered going turbo as everyone says you'll crave more power and such but I have another turbo build I'm working on. I live in Japan and with the Yen/USD rate I can't pass up the current price of an HKS kit which is my main motivation for going this route.
Appreciate the input.

 

Does the kit use bigger fuel injectors and an aftermarket ecu? If so you could likely get to around 400 hp depending on the pulley sizes. If you keep the stock ecu and injectors you’d be around 320. A stock clutch can do the 320 but beyond that I’d recommend an ACT clutch with a stock friction plate. The F20/22s do very well with boost and hp. You should have no problems at all with up to 400 hp. The differential will be the bit that is most likely to fail. The ring gets pushed off center by the pinion and then gernades. There’s a few fixes: Puddymod modifies them for a fair bit of money, a guy i know will replace the carrier bolts for machines studs for about $400 US and it will hold up just fine.Some swap out the entire rear end for 8.8 diffs.

 

Thanks for the input. I already have a FX300 clutch kit installed with 410cc RDX injectors and a deutchwerks 255 fuel pump. My 4.44 rear was cryo'd when it was installed albeit that was like 14 years ago or something. I've obviously changed the diff fluid at regular intervals. Okay, I'll look into the 8.8 diff. Realistically I'm shooting for 350hp.

 

Return the valvetrain to stock. Forced induction won't get any real benefit from that stuff, and its going to kill engine longevity.

 

Hey it's great that you want to supercharge your AP1! I can speak volumes of how awesome it is (when done right)

Those 410cc injectors need to go out in favor of 1000cc Grams or ID's (1050x if you want). Your stock diff will be just fine as long as you don't hard launch the car via 2 step often. Rather avoid drag racing and do rolling pulls.
255 lph pump will work just fine with stock rail and FPR but you can get a premium rail and/or FPR if you want. Your transition to boost will be quite easy since you already have that FX300 (although our community favorite is the ACT HD PP OEM everything else combo for good reason) and you are tuned on Infinity. Once you install the blower and upgrade the fuel system under the hood you can just retune it and you're good to go. You'll get 370 to 400 + wheel HP off of 10-14 psi depending on fuel type (as this affects how much ignition timing you can run) and altitude.

 

Take this man's free wisdom because these engines are becoming harder and harder to come by. Titanium is COOL and a lightweight alloy but on a street car it eventually wears out and can wreak havoc.

Retainers:

• If you want to install it and forget it Ti might not be the best way to go for nominal benefits (the F series cylinder heads are very well built, minus the Ap1 retainer Shenanaggins).
• Steel retainers are a bit more durable and will have a longer service life (Supertech and Ferrea both make some). (I had a friend drop a valve from worn out Ti retainers on a turbo F22C and it was not pretty).

Cams:

• F series responds quite well to boost. I would honestly swap the stock cams back in if you don't want to worry about the strain they output to the timing chain etc. You can also leave them in there if you like.
• Low boost from a SC or turbo will overshadow any NA mods you have done before with 100% stock components. I love the response from a NA car but its a different animal when you are forcing air vs. scavenging for it.
• If you want reliability in mind - nothing will beat the OEM Honda stuff (except from the retainers mentioned above).

Valvesprings:

• I think the Ferrea units you have will be a nice addition / added insurance when running boost.
• Just make sure the retainers and keepers all are happy together and you should be good to go man.

Questions:

• ARP headstuds make a nice addition to holding up to the demands boost places on your engine - I didn't see them listed and is also again nice added insurance.
• Stock head gasket as well should be more than enough for what you want to do too.

 

Billman has found that stock headbolts can provide more clamping force on this engine than arp studs. Remarkable finding.

The higher rate springs would only be useful for higher rpm. With forced induction, you can often get more power from this engine by lowering redline (along with more boost sooner).

Even if your goal isn't max power, and trying to keep the NA feel, high rpm power, etc, all stock valvetrain is still best choice.

 

Honda valve

 

The best way to keep the NA character of this amazing engine is to go supercharged. Turbocharged changes that character instantly. Supercharged retains it while doubling (depending on boost, supporting mods, tune, etc) the HP. Both can be great if done right and it all depends on what you want from the car.

 

Higher rate springs are apparently safer for those running 2 step often. That's what I heard anyway...