IW STi Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
Where going on everybody, I have a tomei catback and a Cobb air intake box and just ordered my Tomei catless downpipe. When I install my catless dp would I be able to run Cobb stage 2 ots map or wait it out to get it tuned. Thank you in advance. BTW 2019 STI
 

·
Registered
Joined
·
5 Posts
I have that same set up on my 2018 sti. I have the tomei catless downpipe and the cobb sf intake. I'm getting a protune via email right now but the car feels way slow after putting on the downpipe. It feels super slow in the low end rpms....does this happen to others? I know i need fueling upgrades and they are coming soon, but I feel like adding the downpipe took away power...at least in low rpms for sure. Any idea to why this is? Do i need a EWG, EBCS? I just spent the money on this e-tune and I'm just not happy, if i can't get to the bottom of this I'll take off the dp and sell it and still with cobb stage 1+....but I'd hate to have to go that route.
 

·
Registered
Joined
·
259 Posts
My opinion is that a catless downpipe setup needs to have a tune specifically for that. It's unclear from your message if you already have said e-tune, but i'd caution you against running a catless downpipe with a stock map.

Assuming you have a Cobb AP as OP, though i also feel an OTS map Stg 2 isn't great with catless downpipes (tho i'm no tuner). Unsure how the newer STi's deal with catless downpipes and making fueling/timing corrections (i own a GD), but boost spikes and boost creep are something i'd avoid as much as possible.

Pay to Play, do it right the first time instead of having a lot of regrets...

I have that same set up on my 2018 sti. I have the tomei catless downpipe and the cobb sf intake. I'm getting a protune via email right now but the car feels way slow after putting on the downpipe. It feels super slow in the low end rpms....does this happen to others? I know i need fueling upgrades and they are coming soon, but I feel like adding the downpipe took away power...at least in low rpms for sure. Any idea to why this is? Do i need a EWG, EBCS? I just spent the money on this e-tune and I'm just not happy, if i can't get to the bottom of this I'll take off the dp and sell it and still with cobb stage 1+....but I'd hate to have to go that route.
 

·
Registered
Joined
·
5 Posts
I am only on the second revision on my pro-tune (e-tune). I ran catless on my civic si and it was killer, huge improvements all around. My tuner said my car is barely creeping, a little around 5k, but not bad compared to other cars. He said fueling is what i need, and then an up-pipe with an EWG....along with a electronic boost control solenoid most likey. Shit just adds up. On the 15+ u can't run dp and intake without a pro tune since fuel gets iffy. I'm still surprised how slow it feels down low. I'll update this when I'm done with the tune and it warms up a bit...i guess that's another thing, front mount intercooler, but that will slow down boost even more i thought on the low end. Hard to know what to get first, or next, or all at once....and i dont wanna add shit and make the car feel slower...like this damn downpipe. Haha it does sound sick tho, and barely smells for catless.
 

·
Registered
Joined
·
1,616 Posts
The Cobb ots maps are specifically designed for the Cobb products. Cobb doesnt make a catless dp so by running that map on your car with the tomei catless dp your going to see varying results. I will say that it is definetly safer to run the cobb map with the dp as apposed to the stock map. Something is better than nothing in this case. I would still highly recommend getting the car protuned for all your mods.
 

·
Registered
Joined
·
342 Posts
with higher flow your bottom end suffers while your top end greatly increases...I chose keeping catted on several setups as I did also prefer the bottom end not being completely gone
 

·
Vendor
Joined
·
288 Posts
This is not true. Higher flow increases power everywhere. The turbo will spool faster. For under 350-400whp it doesn't make as big a difference but it will always make more power with more flow.

with higher flow your bottom end suffers while your top end greatly increases...I chose keeping catted on several setups as I did also prefer the bottom end not being completely gone
 
1 - 8 of 8 Posts
Top