First a little back story:

I was attempting to install a front sway bar. Pretty simple task honestly except by car has seen a lot of salt. First the sway bar link broke, then the bolt for the tie bar to the sub frame broke off in the sub frame. The exhaust looks like is you look at it in a manner that displeases it it will crumble in a pile of rust. So I feel like I would rather wait till I have a full exhaust and hardware replacement on hand when I do the FSB.

Here's my question:

Ive had many performance cars that I have modded and Ive been around many modded cars. On most cars when you do simple bolt ons like cat backs and intakes you don't have to tune them. I undersatdn that if you do tune them afterwards your gains will be greater but they will run with out it. From what I here in the STi / EVO world is if you put an aftermarket exhaust on a car and don't tune it, it will explode and kill your children. I mean does anybody have any reference material to add validity to this statement?

For whats its worth the car is a 05 EVO VIII MR with 97K on it. It came with a K&N typhoon intake, I have no knowledge of any tuning that has been done to the car. If I do exhaust I will be looking for a used AMS TBE with a cat. Its my daily so if the noise is to much I also plan on running the silencer on the street.

Thank you for reading.

 

it would be wise to get a tune. however if you dont boost more than 5-10 psi then you should be ok until then.

My personal 05 MR has a downpipe, runs stock cat, stock midpipe and Magnaflow rear section. 330 wtq/320 whp on virtual dyno. Nice part is it is NOT loud at all.

See my sig

 

If you are just putting an exhaust on it won't blow the car up. There are some mods that if you put them on and don't do tuning and WOT it can go very wrong (e.g cams, turbos, intakes etc.). That being said if you can mod the car and tune after that's always better.

The stock evo MAF is sensitive to intake changes (intake itself, going to non-recirc BOVs) so some changes there will need a tune to restore OEM drivability. If the car is running a typhoon and its running relatively well its probably already been tuned. Unless K&N has changed the design recently, that intake usually needs a tune because of how badly it used to screw with the stock MAF.

 

Thanks guys. Let me clarify that I understand that tuning is wise and is recommend for maximum gains. I am simply comparing the situation of If you buy car A and do intake header and cat-back, you can go out that day and run it at WOT everywhere you go and be perfectly fine, where as if you buy an EVO and due an intake and TBE people say don't go WOT or over a certain amount of boost or you dig your own grave. I mean what happens? Does the air fuel get so terrible the the heat destroys your motor?

I do think my car could have been modded and tuned before because it does have an intake and seems to run fine, and also the oxygen sensor coming out of the floor board under the car looks like its been off before like maybe someone took and exhaust off the car when they sold it. Whats the cheapest way to just see if your car has been tuned?