Help me pick my first engine mod

23
8
Leander, TX
Vehicle Model
Civic Si
Body Style
Coupe
What's up everyone!

Got my first Honda last wednesday and have been lurking since, trying to find ideas for my first mod but I'm seeing a lot of things I'm unsure about. I've tried researching in various older threads but still can't find the answers I'm looking for.

I've seen a few people mention that getting a cold air intake is useless or at least doesn't net as much gains as previous generations. I was thinking a K&N filter with an HPS tube.

I also have seen mention of the P2R spacers. Any good suggestions of throttle bodies to match?

Is it even worth getting just exhaust or should I wait until I can do exhaust/DP/headers all together? Because I've heard some people mention it's pointless without a tune.

Basically I'm just looking for some explanations of specific parts that will/won't fit (seems to be some confusion with the 9th gen) or recommendations on what a good first mod should be :feedback:

I've got the '15 Si Coupe, fwiw.

I apologize if I've misused some terminology, I've got a lot to wrap my head around!

In the meantime, here's some pics!
100_2545.JPG 100_2546.JPG 100_2548.JPG
 
Welcome!

FlashPro, Full-Race or Ultimate Racing downpipe, a 3.5" intake (CAI or SRI), an exhaust, and a tune. These are ALL you need for power related performance mods short of forced induction.

For suspension, get a 24mm Progress rear sway bar.

For tranny, do the CDV delete and either a short shift adapter or full kit, and a weighted knob.

HPS tube and TB spacer are pointless. TB is unnecessary as well.

For appearance, get rid of the dealer stickers, plate holders, and the VTEC stickers. Maybe the rear Civic badge. (these are all my personal preference)
 
vit's posted about throttle bodies before -
People forget the one magic rule: diminishing returns. You can only squeeze so much power out of a naturally aspirated motor, this instance a 2.4L. Once you reach that threshold nothing you do will gain amazing amounts of power or any power at all -- that being said, no one has really done any conclusive TB testing. If someone wants to send me some various TB's to test on a 9th gen (I'll send them back, I promise ;)), I have a local 9th gen I can arrange something with. I'll even do it on a "real" dyno to make naysayers happy.

Something to keep in mind about Skunk2's comparisons: none of the graphs posted are of an internally stock K20 or K24. Why? Because anything larger than a 65mm nets zero hp on a fully bolted K series (K20 going from stock 60mm to 65mm TB gains about 2-3hp). I suspect on the K24 going from 65->70 is maybe 2-3hp as well.

The graphs on Skunk2's site show gains -- but look at the finer details. 11.5 C/R K20A2 (stock K20A2 is NOT 11.5 c/r). Or it's a higher C/R K24, or it's one of the two with a set of Skunk2 cams. And yes, I will tell you for a fact a larger than stock TB will make power when you have a set of Stage 2 cams in the car.
 
Don't forget the tint!
'Course not! That will actually be the very first 'mod'. I'm in Texas so it's pretty necessary.

Thanks for the recommendations squiggy, load of my mind knowing that the TB/spacers are frivolous, one less thing to shop around for...

Any resources on a CDV delete? Never heard of it before.

Also, do SRI/CAI have any noticeable performance difference?

Last thing, could you maybe give me the jist about Flashpro/VIT/tunes in general? I know they remap your ECU to change your engine behavior but I don't know if it's something you tinker with yourself or download like a pre-configured map. Sorry again for my ignorance :( never messed with flashes before, really appreciate this.
 
Any resources on a CDV delete? Never heard of it before.

http://9thcivic.com/forum/threads/clutch-delay-valve-removal.8624/

Also, do SRI/CAI have any noticeable performance difference?

A few horsepower. Go with what you are comfortable as far as cost and potential hydrolock concerns.

Last thing, could you maybe give me the jist about Flashpro/VIT/tunes in general? I know they remap your ECU to change your engine behavior but I don't know if it's something you tinker with yourself or download like a pre-configured map. Sorry again for my ignorance :( never messed with flashes before, really appreciate this.

Vit sends you a basemap, you upload it to the ECU, drive around per Vit's instructions and do a datalog, send it to Vit, he adjusts the basemap based on the log, he then sends you a new map. Repeat ad nauseam (about 30 times).
 
http://9thcivic.com/forum/threads/clutch-delay-valve-removal.8624/



A few horsepower. Go with what you are comfortable as far as cost and potential hydrolock concerns.



Vit sends you a basemap, you upload it to the ECU, drive around per Vit's instructions and do a datalog, send it to Vit, he adjusts the basemap based on the log, he then sends you a new map. Repeat ad nauseam (about 30 times).

I see, sounds work-intensive! How much does that generally run do ya think?
 
Welcome! It looks like you've got some good info to run with so far....

Woop woop? You down with the clown?
 
Don't bother with an Sri. Vit says the stock intake is extremely well engineered. I bought a K&n typhoon intake without looking into it enough and now I feel I wasted my money all for a little bit more noise. Also of you get a downpipe (downpipe/headers is the same piece on our cars) get a catted DP. Catless has a very annoying noise that sounds like a leak, something else I learned through my own mistake!
 
Last question I swear...I read the thread with VIT talking about the PRL intake and how it was the only one netting power, but some people brought up that the stock ECU won't know how to deal with the extra airflow. Do you think I could throw a PRL SRI on my stock '15 Si and net power, or should I just wait until I've got FlashPro?
 
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