How much HP increase with these mods?
 

Ok, if I were to put on a Bonez cat, Bonez intake, and RB catback, how much of a HP increase could I expect? Has anyone ever tested this combo? What kind of 0-60 and 1/4 mile improvement? I'm thinking around 10-12 HP...somewhat noticeable by the seat of pants...and maybe 2 or 3 tenths improvement. Sound about right? Is it worth the cost?

Yea 10-12hp ...IMO you could have any exshuast shop weld you on a 2 1/2 in straight pipe that would flow better than a dual rb setup for 100$. But if you have the cash go for the RB its quality is pretty impressive.

Probably double the numbers you gave, but I dunno off hand. Search on 5th and 6th ports. They're similar to VTEC. They need exhaust backpressure to open. If they stop opening you'll lose all your would-be horsepower gains. If so you'll have to buy or make something to open them at the proper rpm.

Pretty sure the Bonez cat has the SAP "connection" for 5th and 6th port operation.

But c'mon an open air-filter in the engine bay would probably lose you horsepower, and a high-flow cat and cat-back won't give you a very significant power increase... The difference will be noticable, especially if your stock cat is getting up there in miles, but there's no reason to think it'd be greater than 15hp... So yeah, as far as intake, ditch the overpriced Bonez air-filter and buy a cheapo Ebay filter and some piping to make a cold-air intake or CAI that will get air from outside the hot engine-bay.

^^^ ya i agree...except i think youll see a little more hp increase with the exhaust if you can get all high flow...

Ok, I searched <ahem> and a full RB exhaust will give you about 24HP. A cone intake might give you a couple more, and a cold air intake will give you ~6HP.

i bet thats up to 24 hp with a fresh engine ive seen dynos of other cars with intake and exhaust combos and it was more like 15hp range on non turbos

that 24 is to the crank im guessing

Guy said he had 124wHP before, 150wHP after. Might have been 114 & 140. Full Racing Beat exhaust including header. Maybe he's wrong. I only searched for one user experience.

you gotta tune that car to get any real gain. if you get an safc, and tune really good, expect to peak around 160 whp.

Thats probably about right.. I just put on a full header back RB exhaust (Junk yard find for $10 :fawk: ) on my 89 GXL. Huge difference and the the ass dyno says a solid ~20whp. The fireballs are a bonus :)

Feels great. I'll be throwing it on the rollers soon. We'll see if my guess of 180whp mark is correct.

Small streetported Pineapple Racing motor (Turbo housings, 2 piece Apex seals), Pineapple Racing 6port inserts, SAFC, Cheapo Ebay filter, Full RB exhaust.

One of my friends did the same thing. We were guessing that his cat was clogged or something for that kind of gain to happen.

Surprised no one asked this because the answer can change the HP increase alot, but NA OR TURBO? Your profile says Subaru Lagacy..

N/A I'm assuming? How many miles on your old cat? Any indication that it might be clogged? Etc. I'd like to get a real number for a full exhaust. Perhaps people could post their untuned wHP numbers and we can compare those to the stock wHP.

Yes. N/A unknown mileage on the cat. Its not clogged, I used it just to pass emissions, then I threw my old punched out one back on. Until I found the RB exhaust.

I have the bonez presilencer + bonez cat, and the RB catback system and I think it works just fine. It sounds very deep, although it it alot quiter than stock now. I will be ditching the bonez silencer and cat for a RB header and presilencer tho, that should add a few dB i hope :)

So far I've heard 20wHP from a guy whose old cat was working fine. Anyone else care to post their own dyno results? I want to see if 20wHP is consistent or if it varies (maybe the guy's old cat still ate up an extra 2HP? etc.)

Yeah, I should've said when I first asked....a NA.

Well in an N/A you wont's see half as much power gain as if you had a TII unfortunately... but 15-20whp sounds like a good number. Maybe a bit more with a better power curve if you tune it