I was told by the person I bought my car from that my car was tuned with a 5 ft long down pipe and that is it. I extended the pipe to the back of the car (3 inch). I want to put a muffler on it now. It is going to change the tuning of the car if I put a strait-through muffler on the end? It is set up for 25 psi.

 

Explain a little bit more about your setup.

Car.

Motor.

ECU.

What it's tuned with.

 

It is a 95 Civic with a 1.6 vtec sohc.

It has Wiseco pistons, Eagle rods, Acl bearings, Supertech block guard, Arp rod bolts and head studs, full machine work from P&R in Pittsburgh, 255 Walboro fuel pump, Presicion 880cc injectors with resitor box, ported and polished head, Omni 4bar map sensor, 3 inch intercooler piping with a 32x12x4 intercooler, 50 trim turbo pushing 25 pounds.

It was dyno tuned by Pittsburgh Performace for around 360 hp and 312 tq and it has a Hondata s300 computer in it. The whole engine has a total of 3000 miles on it now.

 

Is it track only or are you gonna daily this?

 

Its my daily car.

 

Slap a muffler on it. If there is a big change in performance then you'll have it get it re-tuned. No way around it. No one can tell you what will happen for certain. I can guess that the change will be negligible.

 

So its not going to cause any negative effects on my car except maybe loss of a little power?

 

Any answer you get is pure speculation. You won't know until you do it.

 

Kind of a complex setup...I would get a tune...it can wait for a little bit I imagine without having any crazy unsafe effects.

 

If this was moved into the FI forum it might get better responses.

 

^ true. Most people here have mufflers

 

So your saying.. Downpipe off turbo -> To 5 foot of exhaust and that's it?

Do you have a wideband?

It's going to change the air flow, so yes it's going to throw the tune off. A/F readings will be different.. and that could be leaner or richer.. IE: Can be dangerous

If it was mine, I would retune.. period.

 

^ dangerous for him like driving for a month dangerous...or dangerous like blow up within the first 100 miles?

 

Depends on how he drives. If he's driving WOT and the modification leans the engine out for long period of time that's bad news.

If he's got a wideband, i'm sure it will be fine... waiting for that answer

 

No I don't have wide band. I just have 3 inch pipe running to the back of the car right now. I just had that done... I was getting carbon monoxide in the car (about 150 pom). Do you think just adding a peice of 8 ft pipe could change the tune by too much? I'm not wot all the time, I get on it probably 2-3 times a day for about 10 seconds at a time.

 

I would use a 3" catback so you dont have a restrictive flow. use and straight thru muffler (vibrant sleeper, magnaflow) and maybe even an inline resonator and yu wont have any issues.

Heres 3" kits on the cheap:
http://www.vrsexhaust.com/TUBING_KIT.../honda_tk.html

 

So as long as I get strait through stuff, I should'nt be running lean?

 

I think I'm going to retune after I get my muffler just to be safe.