OK, here's my prob. I have a ls teg with an Injen CAI and a hi-flo cat with 2.5" Airmass Thundermuff catback exhaust system. I have noticed good gains in the top end where it needs more flow, but it either seems to have lost some power in the bottom, or maybe just by comparison my low end seems laggy. It's been suggested to me that it's too free flowing and a lack of backpressure may be to blame for the slow bottom. So I was wondering what I could do to improve my bottom end. I havent decided on which kind of header i want yet, 4-1 or 4-2-1. I was thinking possibly the 4-1 would restore some back pressure down low helping that and then give me the good flow up to that 4-1s r known for. But 4-2-1 claims to be better for low end power, but i'm curious to think if it might flow too well on bottom and the restrict up top. What do yall think?? Also, I was considering either buying a lightweight flywheel, or having my stock flywheel cut. But keeping in mind that this car also needs to be my daily driver, will a lightened flywheel hurt my reliablity a lot? would a 12.5 lbs still give me decent acceleration, or can i safely go with a 8.8 lbs and not loose too much reliabilty except for maybe a little decrease in gas mileage? What would yall recommed for some increased bottom end power and real quick acceleration?

 

First of all we need to know what kind of car you have.

A lighter flywheel isn't going to make anything break sooner so it doesn't really affect "reliability" in any way. It'll be a bit trickier to launch but nothing major, it'll make the motor feel like it wants to rev more easily. Revs will also drop quicker when you shift. I would go with a lighter weight aftermarket piece rather than have the stock piece lightened, that way you know it's at least not supposed to fly to bits on you (yes that would be a bad thing).

You're not going to increase 'bottom end' that much regardless of what you do, you have a 1.8-liter inline four. The whole 4-2-1 = bottom end/midrange and 4-1 = top end myth is way exaggerated, it's just a sort of general rule that tends to apply. There are a lot more factors in how a header performs than just how the primaries are merged into the collector. To make a recommendation on a header we would need to know what car this is and what other mods you have.

 

my bad, it's a '95 integra ls. The only engine mods i've done are the intake and exhaust listed, nothing else as of yet, more comes as the money comes, u know how that is. So what do u recomend?

 

Backpressure= bad.
Exhaust velocity= good.

For best performance, you need the least possible backpressure with the highest exhaust velocity.

Read this little article, it will explain what's going on.
http://www.hondalife.com/articles/backpressure.htm

 

EXACTLY

the engine is a big air pump. stuff air into it, light it up with fuel n spark, and get rid of that sh*t as fast as you can. the quicker this whole thing happens, the faster you go h:

 

i dont think you guys are really helping him with your technical jabber. my advice is save up your money and buy a jackson racing supercharger. that will give you more low end power than you know what to do with, and in the long run its probably a better bang for your buck than just doing it piece by piece. and besides, if anything, this header your buying is only going to decrease you low end torque.

 

"Technical jabber" is never a bad thing. Well usually. Besides, saying "buy a JRSC" is no more of a recommendation towards a header than anyone else has given.

Anyway.

Comptech, DC, etc make nice headers and you'll get about the same results from each. My main recommendation would be to get something made from stainless steel rather than ceramic-coated mild steel.

 

I actually have been thinking a lot about buying a JRSC....they sound really good. I'm still contimplating brands of FI and weighing the turbo or supercharger argument, but i'm thinking super, cause i'd like the insintaneous effect, i'm also trying to decide between roots and centrifugal. As to header selection though, why stainless steel? I thought I remembered heard ceramic coating was better, because of heat resistance and such. which is better and why? Stainless seem to discolor with time as i remember too, right? but then again, if it preforms that much better, i don't mind discoloration. Also, on the subject of FI, which would u suggest, turbo or supercharger, and why? if super, what brand and type? as i've read, vortech has a innercooler for their centrifugal supers....does a jsrc have problems with heat soak or reliability, is the power it drains from the engine a big issue? keeping in mind that my car will be daily driven, what would u suggest? thanks for all the help! oh, and btw, i can understand most of the technical babber, so don't worry too much 'bout that, thanks again!

 

if ur gonna use a SC...dont use it on a LS......wait and save up for a GS-R..... they come out alot faster on a gs-r.. i have a LS and i waz thinkin about SC'ing it ..... but i dunno people have told me its a waste of money to SC it...especially since its not vtec

 

I've also heard that gs-r's are better for sc, but i thought that ls's are better for turbos. Why is one better for one application and not vice versa?