Hmmmm.... I don't know why we are talking 'back pressure' in the LNF section.... cause when your talking turbo, go big diameter, or go home. You don't want to be choking that turbo on the downstream side.

I try to assume they're all keen enough to upgrade that with the beauty piece being sold by Synapse.

 

well **** then lets just get a 6" pipe and be done with it. If you get a pipe that's too big you slow the exhaust gasses down exiting the exhaust and that's just as bad as backpressure...

 

Are you talking turbo, super or N/A?
Cause if your talking on the LNF (turbo), you'd better re-think that.
Turbo'd engines are a very different creature than the other two, on the exhaust side.

 

tell ya what there chief.

lets compare something.

my cute little 3 inch dp and catback exhaust to ANY 2.5 setup out there. which one will make more power on my car?

btw. comparing turbo to blower is stupid.

 

anything. When your pipe diameter is too large for the motor the exhaust velocity will slow down. You want the exhaust gasses to exit the car as fast as possible. You have to find the proper diameter so that you aren't choking it and on the flip side you aren't hurting the velocity of the exhaust exiting the car...

 

A turbo'd car gets it's 'backpressure' (gawd I hate using that word) from the turbine.
It's not the same as a blown or naturally aspirated engine.

 

::looks at dyno numbers::

um
right......

go forth and spread your........... knowledge.

 

Dude you are also probably between 275 hp and 300 hp at the wheels (just a guess based on your mods) which puts you in the range I said is good for 3" exhausts...

 

i like the Hahn and corsa tour

 

if back pressure ment so much. why do big turbo guys run 5inch dp's that are about 3 ft long?

oooohhhhhhhhhh the pressure build up is between the head and the turbine wheel.

close. im over 300.

i have had the same exhaust from 230 whp on up.

 

I bet you knew you were going to be built up quite a bit in the future. Which makes sense to buy the exhaust for what you are building rather than buying a small diameter exhaust and then spending more $$$ when you do your mods and need a bigger exhaust. You were looking a head I'm sure. but like I said for most stock or lightly modded Cobalts 2.5" or 2.75" would be sufficient and work out nicely...

 

Stock SC or TC? If you are talking SC, a 3" might be too large. If you are talking stock TC (with 55 more HP), it would be sized appropriately.

 

IMHO either. If you plan on modding it out to be the friggin animal then yea go big now so you don't have to be constantly changing exhausts but if you just want a CAI and maybe a tune then 2.5" or 2.75" would be sufficient.

 

You have a TC... but a 3" on.

 

That is what I assumed based on the information I received from Hahn. They think that it is appropriate for anything 250-500 HP.

I'm not planning on doing much modding other than the exhaust and maybe an intake. I think that the 3" would be fine for us stock TC guys...

 

3" is definitely fine

other cars push 600+ hp out of 3" pipe, under 300 won't be a problem

 

2.5 inch dp and 3 inch cat back

 

the stock DP is 3in I believe

 

I really dont think anyone could beat the Hahn exhaust..

 

Ok when it comes to turbo cars the only "backpressure" you need is from the turbo itself. As far as the exhaust goes you could hack it off after the o2 sensor and it wont make a bit of difference. I have personally run open downpipes on my talons at the track. The bigger the better. 2.5" is good for up to 400hp... how much are you honestly expecting to be making out of this LNF in the near future. I mean you could go and spend the $1500 get the hahn programmer and exhaust and get an extra 30hp and you are only at 290whp...

Get the 3" since its the only one available right now and look at it this way, You will NEVER have to replace it unless you go over 500hp.

Sidenote...$1500...30whp... I think I will wait...

in general you want to keep the intake mani pressure higher than the exaust mani pressure to make maximum hp and tq... so in other words bigger is better for the exhaust. The reason why the exhaust speed would be decreased is because it flows more. you are moving a higher volume through it regardless of speed. I am talking about cfm's, thats all that matters.

 

Hahn makes some nice parts for sure.

I think the company that made my cat back is working on a system tuned for the SS/TC.

From what I was told, the first prototype/version of my system yielded so so results. Apparently they reduced the pipes after the y to 2.25 and bettered stock nicely both at the bottom and top. As this companies history came from 2 stroke machines, their obsession with fine tuning exhaust has carried over to their automotive side with specific attention to the power band. It seems to me, in the LNF car, that ultimate flow might actually have some negative effects. At least on an otherwise stock car. I can report that my car seems to run less boost than other examples. I can't be sure it's the cat back giving me the gift, but it's likely helping out veery well considering what the dyno showed.

While the difference in the ss/sc and ss/tc systems are likely easily overcome to fit, I would prefer a system that is tuned to sound sweet. That turbo in the way makes all the difference. Most systems will be adequate for your needs, but I have seen too many guys have to chop up well made SS systems to get them to sound just right. I think mine does. check my sig.

 

When it comes to supercharged or N/A cars, exhaust pipe size is very very important. When it comes to turbo cars, the turbo is already restricting the exhaust considerably, so as big as you can go wont hurt at all. For most of us turbo'd, the 3" is all we will ever need (unless you are one of the rare few that are going to hit over 500whp). Going big on the exhaust with a turbo will not hurt, it can only help. Going 3" on a STOCK superchaged car (no stage kits) can hurt performance.

 

From what I have heard about Hahn's products he knows his ****. Get the exhaust and call it a day

 

..its a work of art, I almost hate to put it under my car.

 

hahn FTW