I know there has been a lot of talk of this as I've done a lot of searching in the past 24hrs. But really all that leaves me is a 50/50 ratio of "you're fine" and "retune or you will go boom".. I don't like going "boom".

So anyways I just bought a test pipe from STM and I'm welding up a V-Band to it as my JunB.L exhaust is flanged for such. But before I put anything on my car without a tune (since I'm still new, not dumb but new) I like to read about others experiences before hand. And that is what brings me to post this!

Here's a list of my mods as they do matter in this case:

BR UICP
AMS I/C
Perrin Intake w/ K&N Filter
Perrin Downpipe
JunB.L Exhaust
Hallman Boost Controller
JDM MR BOV (recirc.)

The car was tuned at English racing and put down 333whp on the stock ECU (which I'm happy with for the mods, they aren't much). Will opening the flow of the exhaust REALLY change A/F ratios SO MUCH that I will need to retune? I understand if I did that I could probably pick up some HP/TQ due to the better flow but is it necessary?

I'll for sure call Aaron and Luke to get a second opinion but I'd definitely like some input from those of you who have done the install without a retune.

Sorry if this is sort of a post of a post of a post of a post, but there really doesn't seem to be a definitive answer on any thread, just a bunch of theories and hub-bub.

Thanks in advance for any input of help you may be able to give!

 

The test pipe may change the tune considerably. You will be running leaner across the power band. Hook up a wideband and see for yourself. You may not go boom but I wouldn't be surprised if the car drives like crap until you retune. I'm sure you'll be fine driving around town but I would avoid WOT pulls until you're tuned.

 

This guy speaks the truth. Surprisingly, just a test pipe can make a big difference. I would certainly stay out of WOT until you get a good tune.

 

****. LOL!

Alright, well I'll hold off on installing the TP and wait until my manifold and turbo gets here. No sense in retuning for a few horses.

I really appreciate the input though guys, I'm new to the Evo world and there's a lot I still need to pick up. So thanks for helping the FNG out!

 

I think you would be fine. Should you get retuned, yes. Can you put it on now and retune when you install the new manifold and turbo, yes. Your car is already tuned for a bit of parts, you're only making it a little easier to breathe. It's not like English tuned it perfectly for your current load levels then went straight to catastrophic failure if you exceed them. What you do is taper the tune to be safely richer with less timing as the loads go up past current. I am not advocating running around untuned with a lot of mods, but in your situation you should be fine. Post back with what English Racing has to say.

Also, you should look into O2 housing/LICP before your next tune as well. Those are some of the first breathing restrictions to take care of.

 

For sure! I actually have the LICP in my closet! Just haven't put it on yet as I am waiting for parts. I didn't buy an O2 housing though because the new turbo/mani are externally gated. But thank you for the input man!

 

RE tune more power. You can leave it untuned though... Wont do anything. I'd wait until you have more mods than retune it to save money.

 

Get more parts then go for another tune

 

You will be fine. If your car has been taken care of, you should have no problems.

I have been driving on a modified stock tune since March when my car put down 260hp to the wheels without a single mod. Since then, I've done the full bolt ons, including test pipe and waste gate dump, and my car runs perfectly smooth. Maybe it is because my car was tuned when it was stock, I'm not sure. But, it's been running great since throwing all my bolt-ons on. I will say however, that since it is getting colder, my AFR's al starting to lean out more. Maybe it's time to drive to Tampa…

 

Spoke with English and they said I'd be okay with installing it as long as I was still running MAF. I guess there has been some issues with Evo's that run Speed Density after the installation of a Test Pipe when it wasn't tuned for one.

So I found the ONE and only good thing about MAF. LOL

 

So how did it turn out? About to do the same but will be tuning in next week.

 

^^^^^^
turbo, cams, injectors,e85, head etc etc