exhaust size for supercharger? - Honda Forum / Acura Forum

soldiermanny · 07-25-2007, 02:35 PM

sup guys, had a few questions about going forced induction. first off let me list my mods... got a greddy header and greddy sp2 exhaust thats 60mm and also a injen cai. my question is, is my exhaust to small for supercharging? i know i already have to change my intake to a short type intake, but do i need to upgrade my exhaust to a 2.5 atleast? i am thinking of getting a jrsc and making a list of parts to save up for. i'm already thinking of upgradding the fuel system and ignition system, also some cam gears to throw into the mix. as for the intake, i might slap the stock one back on cause i have a brand new k&n. i'll probably modify it to get more air in(cut out side holes and remove bottom?) any insite would be great and thanks in advance!

Sirfallsalot243 · 07-25-2007, 03:13 PM

HAVE TO is a bit harsh. IDEALLY, yes- you would want to get a better header and a bigger exhaust. HOWEVER, thats not to say that you wont see large gains with the addition of a supercharger, without upgrading your exhaust. For example, the previous owner of my car ran a 60mm Apexi N1, but had it turboed at 8psi. He still made over 240whp, and got no traction in first or second gear, lol. Its your call... you WILL make more power with a bigger exhaust, but leaving your exhaust as-is wont kill your power. Id say the difference would be in the area of 10-20whp with your current exhaust versus an ideal one. (Thats a total guess btw).

My advice: go ahead an boost it. Youll like the feel of a SC, and you can always go ahead and get a bigger exhaust later on.

A tip though: look up the differences between a twin-screw and a centrifugal supercharger. You may decide that you like a centrifugal supercharger better (Vortech makes one for our car). The gains are better with a centrifugal- but the price is also higher. I could go into detail about the differences, but Im trying to make this post relatively short.

soldiermanny · 07-25-2007, 05:27 PM

man sirfallsalot, your always on top of the game. you always are quick to respond with some good info. so my guess was pretty much on track, i sort of knew i could use my current setup and make decent power with the jrsc. my goal is to be between 200-225 whp. i think i could do it with my exhaust system. i dont want to go with to much boost at first. like 6 psi to start out with and get a hang of the power and then upgrade to a bigger pulley and exhaust later on. i like having control of my car and not lose control because too much power. i hate seeing young kids push high hp cars and not know how to drive it. well thanks again for the info sir, rep if i can. if anyone else gots anymore info, hook me up...

Sirfallsalot243 · 07-25-2007, 06:30 PM

Be careful pushing more boost- the GSR has a 10:1 compression ratio, which is relatively high for forced induction. A properly sized turboed GSR cant handle much more than 7psi without running into issues (assuming the compression ratio hasnt been altered). You might be ok to raise it more with a supercharger, but keep in mind that the engine does have its limits.

ksniperfox · 07-25-2007, 07:25 PM

isnt the vortech the belt driven turbo? where you have parasitic drag AND lag?

a header opened up a surprising amount of power for me. on stock header and 5.5psi i made 30whp over stock. i then went to 8.5psi and a header+hondata intake gasket, and made +30whp again.

and fuck only starting at 6psi and then going more. that shit gets expensive. if you wanna pay to go to the dyno twice, go for it. also keep in mind, if you change the blower pulley, you have to remove the entire blower. thats about 4 hours of labor if you do it yourself. or about $300 at a shop. plus dynotime. so have fun lol. might as well do all the upgrading at once, be smart, and save $. 220whp isnt going to be THAT fast.

daveb91 · 07-25-2007, 07:47 PM

There are plenty examples of 10 psi JR GSR running with no problems. Best way to up boost on the B series is a stepper pulley. Most use a kamakasi sp? header for the JR setup. Also look into the LHT intercooler for the JRSC.

female four · 07-26-2007, 04:17 AM

Keep the setup you have now and upgrade when you want to. Like how this statement was said...

Quote:

Originally Posted by Sirfallsalot243

HAVE TO is a bit harsh. IDEALLY, yes- you would want

My advice: go ahead an boost it. Youll like the feel of a SC, and you can always go ahead and get a bigger exhaust later on.

soldiermanny · 07-26-2007, 02:41 PM

thanks for all the info and advice guys. rep all of you if i can. feeling like a rep whore today. lol. anyways, i know 220whp isn't that fast but its fun and pretty much all i need for the streets. if i wanted crazy power i would of got a faster car to begin with. i love hondas and their relible quality, just having a little more pep in my dd is all i was going for. thanks again, out...

PickleTeg · 07-27-2007, 09:08 AM

220 WHP is nothing to cry about...you also must remember that you are going to have a TON more torque than a NA car making 220 WHP. A GSR is a good platform to start out with and 10:1 is great for a JRSC car. You must remember that our Roots blowers don't push as much CFM as a turbo does. 10 psi on a 60-1 is much different than 10 psi on a M62 blower.

BTW: Look at my Dyno sheet on this forum from the last time I was tuned...a 10 psi JRSC GSR should look similar to that.

soldiermanny · 07-27-2007, 03:04 PM

Quote:

Originally Posted by PickleTeg

220 WHP is nothing to cry about...you also must remember that you are going to have a TON more torque than a NA car making 220 WHP. A GSR is a good platform to start out with and 10:1 is great for a JRSC car. You must remember that our Roots blowers don't push as much CFM as a turbo does. 10 psi on a 60-1 is much different than 10 psi on a M62 blower.

BTW: Look at my Dyno sheet on this forum from the last time I was tuned...a 10 psi JRSC GSR should look similar to that.

nice numbers! quite a build you got going on there! must be pretty exciting to drive. so you think i would need 10 psi to get to where your at in numbers?

PickleTeg · 07-28-2007, 12:05 AM

Well...I am intercooled for one....I can run much more timing than a non-intercooled JRSC car due to my much lower IATs. I am also running Crower FI cams and those made a huge difference along with the Kamikaze 2.5 header and test pipe. I also benefitted from cam timing adjustments. If you run a stock GSR pulley and a MVM stepper pulley you will be right at 9 PSI. You will need a good engine managament system to run 9 psi on the JRSC.

soldiermanny · 07-29-2007, 06:24 PM

well i am convinced! i drove the new supercharged cobalt yesterday and i loved the response of the sc. i attended the rev it up event sponsored by chevy at disney yesterday and got to drive the new cobalt ss, trailblazer, impalla ss and corvette! the corvette track run was insane! it was the ls2, but still, 400hp and torque is no joke! the zo6 run costed extra and was sold out.

the only thing i didnt like about the cobalt ss was it redlined to quick, 6500rpms. i was used to my 8000 redline.

anyways, i will be going thru with the sc idea. dont know when, but will be either by the end of the year or early next year.

out...