I will be getting my car tuned again soon and i was just wondering if 3 inch exhaust would be negative in anyway on my daily driver eg hatch with a gsr turbo setup? the downpipe is 3 inch but someone before me had a crappy 2.5 inch exhaust welded from the downpipe back. i will be tuning it on 9lbs daily and am shooting for 280whp on a safe tune. thanks for any helpful replies

 

3 inch would work great

 

You can make make your whp goal with a 2.5 inch exhaust.

 

well i know i will hit 280hp easy but im just wondering what gains i would expect to get out of upgrading to 3 inch?

 

it wont be too much, and you would be able to gain a few more ponies, but a 3" exhaust wont be cheap if youre on a budget.

 

I should have rephrased my response. You can hit your whp goal with your current setup so I don't see a reason to upgrade. If you plan to push the whp later then yes you will need a larger exhaust but if you only want 300whp then you are completely good with what you have. I don't see a reason to spend money until necessary. Also, what injectors are you using? If they are reaching their max at 280whp then you're going to need new injectors as well if you want more power. This is why its important to pick a HP goal and stick with it because it's not cost effective to keep changing things up.

 

3" thermal catback with 3" spoolin performance downpipe on my turbo swap gsr hatch... runs great! im running t3/to4e turbo 60 trim, spools pretty fast 8psi for now... till i can get another boost controller..

 

You could probably make that kind of power with 2.5", but upgrading will help.

If you're turbocharged or have a header with a good collector, the only job for the tubing after the turbine/diffuser is to provide as little restriction as possible. Bigger is better, as long as you can do it practically. However, beyond a point, there are no returns for larger tubing.

You also have to be sure that you tune the engine in either case to make sure it doesn't run too lean.

The only downside of larger tubing (as long as the car will be tuned) is that it will be louder.

 

i have heard from a company called powerflow in the u.k and a chap there told me alot of people go for big exhuasts and don't have the power the will fill the tubing.

he said that heat rises so in a pipe it will only be flowing in the top half of the pipe therfore alot of people really don't need the extra piping..... he also told me alot of rallye cars that they do work for have quite small exhuast sizes, purely because they want repsonce and as stated above the pipe is only filled with exhasut in the top half or 2/3 of the pipe. so i guess i'd say go for the 2.5 piping.


he is telling me crap........i can understand where he is coming from but really????

thing is when i have seen the rallye cars up close they do not have big 3inch exhausts.
is there such thing as 2.75 exhuast lol try that and be different mate.

 

^are you making a suggestion or asking a series of questions? the price difference of 2.75" and 3" is minimal at best, and the 3" is only really needed if OP wants more power down the road. a 2.5" exhaust is efficient at 300whp and i would only go 3" if the power goal will be over 350

 

kinda both lol.
making the sugestion that they make good exhuasts....
also asking questions as well.
as i recommend them but just wanted to know if this chap was talking crap... as then i would avoid them if he is talking ****.
if he is correct which by your answers he is then it reinforces my belief that they are a good company.
i'd say give them a call then if you are in the U.K.

 

If you want max power for minimum boost then you want an exhaust that at least matches the downpipe. What size turbo are you working with?
I dont know about better response from smaller piping...i noticed a HUGE increase in spool when I went from a 2.25 to an open DP.

 

Just run of the down pipe

 

The guy talking about rally racing and exhaust sizes...are you sure the guy wasn't referring to NA cars? A naturally aspirated motor needs the exhaust system slightly smaller to maintain exhaust velocity, which will help to pull the exhaust out and not create back pressure. The exhaust pulses will help pull consecutive cylinders' gases out. A turbo motor needs as little of restriction as possible. An open downpipe or a super short pipe right out the hood will be "best". Anyway, the turbine basically wants as much exhaust pressure on the intake side and as little restriction on the exhaust side as it can get to spool faster.

 

i had the same set up on my jetta.., thermal r&d is great

 

[QUOTE=thumper64;43364215]The guy talking about rally racing and exhaust sizes...are you sure the guy wasn't referring to NA cars? A naturally aspirated motor needs the exhaust system slightly smaller to maintain exhaust velocity, which will help to pull the exhaust out and not create back pressure. The exhaust pulses will help pull consecutive cylinders' gases out. A turbo motor needs as little of restriction as possible. An open downpipe or a super short pipe right out the hood will be "best". Anyway, the turbine basically wants as much exhaust pressure on the intake side and as little restriction on the exhaust side as it can get to spool faster.[/QUOTE



he was talking about turbo cars as i had a starlet turbo and he was saying anything over 2.75 was a waste on mine as i wanted under 250hp yes they need as little restriction as possible but if you read what i wrote i said that the exhasut gases do not fill the whole piping in a big exhaust, so when you say bigger is better it is not the case.
yes it is up to a point but if you are not using all the piping it is simply just there and not being used which is a bad thing as the flow will be slower than in a smaller diameter pipe. exhaust gases are hot and the hotter it can be kept running through the system without soaking into the car the better as hot air is less dense and therefore flows quicker.( in the engine bay obvisouly not as you want this to be cool for intake temperatures ) Why do you think people use heat wrap..... it is to keep the heat in as it makes the exhuast flows quicker when hotter. i actually had a screamer pipe on my starlet and it decresed horsepower so striaght out the hood is not best in all applications.


basically without reading in to deep with what i am saying......
MY ADVICE would be go and talk to your local custom exhaust company and sit down with them with a cup of tea ( hey i'm english ) and chat to him about what your needs are and your goals...... do not ake the advice that bigger is better.
after all we drive 1.6 honda engines and how often do we smoke things like 3 litre v6's ..... all the time.

this is by no means a rant at thumper64.

 

well thanks for your responces, yes i am looking to hit 300whp, and i believe my injectors are 550's but i do not plan on making more than 300 hp anytime soon due to the fact that it is a bone stock gsr, and i am having it tuned one month and i was planning on putting a high flow cat on before i had it tuned, but i was just wondering if it would help to go 3 inch to make more power, but if it isnt necessary until 350+ whp or so then i will stay with my 2.5 and just have a high flow cat welded on, i will not be able to pass emissions without a cat

 

let us know what figure come out of the dyno man.
good luck mate.

 

Hi.
I feel some problemmy.
1 My engine does not wants to work more than 8000 rpm, there is a detonation.
2 At a pressure of of more than 1 barrels - knock occurs
3 When driving over 200 km / h - EGT rises to 950 degrees Celsius.
EGT Sensor installed in the hot turbine housing.
Hybrid Turbocharger GT 28/30.
Manifold spoolin SPfab Quick4AS SPfab Quick4AC, Spoolin Performance
SPoolin Downipe AC Flex pipe.
Exhaust pipe diameter of 62mm. Integra TYPE-R,2.3" tanabe hyper medalion exhaust - Zerotohundred.com My muffler has no direct pass, there is a maze.
ENGINE B18C TYPE-R, porting head, compression ratio 9.5: 1
I think that I need to make a tube 2.75 ", and
install another muffler (straight-through muffler)
But one person said that to all fault Manifold that the exhaust system is not to blame.
What are your opinions?
Thank you.

 

In what world is bumping a 5 year old, dead thread with your completely unrelated problem even remotely OK?

https://honda-tech.com/honda-civic-d...sting-3002401/

Read the rules. Make your own damn thread. Go get the engine tuned - detonation is caused by **** fuel, or a **** tune.

 

: объятия:
You're so kind.
I just do not want to create extra garbage at the site due to my insignificant problems.
The setting is made on an experienced dyno tuner.
Thank you.

 

That wasn't a request. Follow the rules. Make your own thread.