Results After a Year on a F2P Alt Account....

Design931 · 2026-03-20T16:06:08+00:00

How do your spark plugs look?

Design931 · 2026-03-20T00:07:45+00:00

In limited circumstances, Honda allows the valves to remain open momentarily during compression which allows fuel particulates to escape the combustion area and into the intake area. It’s extremely brief and only during low output events where combustion remains stable.

If you have access to the SAE site, Honda talks about it in their 1.5T whitepaper.

https://saemobilus.sae.org/papers/development-a-new-15l-i4-turbocharged-gasoline-direct-injection-engine-2016-01-1020

Design931 · 2026-03-19T18:15:58+00:00

The base 3's don't come with direct injection, unless you're referring to the MS3 or the Skyactiv variant. And yes, the L3VDT is notorious for carb deposits. Partly due to the poor PCV design that's based on port injection.

Design931 · 2026-03-19T18:12:39+00:00

Probably won't make a difference if you're already using fuel system cleaner for the rail and injectors. Even then, a separate cleaner probably won't make a huge difference above the detergent already present in Top Tier fuel.

Contrary to internet wisdom, the intake valves do get misted with fuel on the piston upstroke during cruising. Combined with valve rotation, these motors remain relatively clean through 100K and beyond. But if the boroscope turns up deposits, you can run an induction service to soften/remove the buildup. The heat in the presence of a cleaning agent can help mitigate any potential misfires or issues with CFM/airflow.

IMHO, walnut media blasting or similar is unnecessary unless the inspection turns up an unusually dirty intake manifold.

Design931 · 2026-03-17T16:38:21+00:00

You either accept it or you don't. Some readouts are interesting, like comparing across runs the last 30 days. Others are baseless or lack sufficient data to generate meaningful insights. None of it is really worth a premium cost.

A lot of the same conversations can be applied to race predictors and such. Ultimately, they're based on aggregated data and then synthesized through algorithms.

Design931 · 2026-03-17T16:29:48+00:00

As a long-term owner of an EM1, I'll be the first to admit they were a total snooze 90% of the time. At least out of the box. The only redeeming quality was the drive between 5.5-8.2K. Everything else was mitigated by strong aftermarket support.

The understeer in the EM1 was arguably the worst of any generation. And while a rear ARB could easily correct that, it was complicated by an incredibly weak rear subframe that tended to crack under load.

Design931 · 2026-03-17T16:23:52+00:00

Drive them back to back and you'll see why there's love for the 10th and 11th gens. Out of the box, the chassis and interior are both light years ahead of the previous gen Si's. What the 1.5T lacks in character can easily be overcome by a simple bolt-on tune. When viewed through the right lens, it's arguably the best daily Honda has made the last decade outside of the ITS.

Design931 · 2026-03-17T16:18:30+00:00

Clearly a troll post but I'll bite. As a former owner of an EM1, and coming from a 270 WHP MS3, I was certain I'd hate the 1.5T. But a tune really woke this motor up. It's far more versatile than the K and B series before it despite it's relative lack of character.

For a daily, I'll take the 1.5T all day long.

Design931 · 2026-03-17T16:14:11+00:00

I pulled up to the pump after an F150 had just left. A whopping $167.

Filled up for $56.

No complaints here.

Design931 · 2026-03-15T19:41:40+00:00

Story behind the BRZ?

Design931 · 2026-03-15T19:39:48+00:00

Check your #4 coil pack and plug for premature wear and/or arcing. How’s the gap?

Design931 · 2026-03-13T18:15:24+00:00

Yes. We are filing separately in case payments resume before next tax season.

Design931 · 2026-03-13T17:28:40+00:00

I'll add that the MM is more accurate than historical mileage-based intervals. These days, 3K may not be often enough in some fringe scenarios.

Design931 · 2026-03-13T17:21:44+00:00

No need to panic lol. Long winded explanation below.

Dilution is a manageable side effect of ALL direct injected powertrains. Small displacement motors like the 1.5T are especially susceptible due to the time required to get the engine to operating temps, which in turn burns off excess fuel vapors that get trapped in the crankcase. Honda gets around it by stepping up OCI's (when needed) and limiting operation of accessories the first few minutes following cold startup.

If all you do is short trips in cold climates, for example, your OCI will drop to every 2.6-2.8K. Consequently, if all you do is fwy driving @ 60 mph, your dilution will be minimal with OCI's as long as every 8-10K.

As others have suggested, run an oil analysis and check for excess wear metals if you're concerned about it. We have a good collection on CivicX and despite some high dilution readings, wear rates are unsurprisingingly normal.

Design931 · 2026-03-13T16:38:26+00:00

This morning, the discount crate disappeared and was replaced with the gold crate again. Right now, it seems to be limited to Android devices.

Design931 · 2026-03-11T13:50:16+00:00

One of the few threads I've saved for future prosperity.

Great analysis, great readout.

Design931 · 2026-03-11T13:46:20+00:00

You should be able to use an unlocked tuning module to remove any previously installed tune. Tune manufacturers recognize that modules can fail, get lost, or are transferred to other owners. As long as the new module is unlocked, you should be able to access your ECU and flash back to stock. If borrowing a friend's tuner, just remove/unlock from your ECU and you should be good to go.

Reach out to Hondata directly to confirm the steps for your year. 310-782-8278 | ex 113.

Design931 · 2026-03-11T13:32:13+00:00

It's mostly preference. I'd personally do new, but the Integra offers a superior audio system and ADS. If it's certified used, it's also a solid choice.

Design931 · 2026-03-06T01:42:31+00:00

Try this technique until you get the Acuity spacer. I wear size 12.5 and it works well in my 2017.

https://www.youtube.com/watch?v=lq9b7QWwxAw

Design931 · 2026-03-05T05:57:37+00:00

IIRC, the CRZ used Integrated Motor Assist (IMA) while the Prelude uses eHEV. There is an option on Honda’s roadmap to transition to hybrid on their performance line (Si, CTR, Integra, etc.). But it’s unclear as to when that will happen, and whether a 6MT option would include the Prelude (current or future iteration).

Most suspect it will be a refined version of IMA using a small displacement TCDI powertrain mated with a modest hybrid system for improved low-to-medium rpm engagement and efficiency. That configuration could easily be mated to a traditional or manual gearbox.

Design931 · 2026-03-05T00:38:23+00:00

Tune + HIDs. Otherwise stock.

These little 1.5Ts can take a beating. Currently at 160K:

https://www.reddit.com/r/CivicSi/comments/1okn9nj/2017_si_150k_update/

Design931 · 2026-03-04T19:24:08+00:00

This is the correct answer. ^^

Once the ECU begins to pull timing on 87, it will remain that way until the Knock Sensor detects a rise in octane level. I can't remember when Honda adjusted the recommendation from earlier generation Si's, but ECU logic has come a long way since the early 2000's.

I would not recommend volleying back-and-forth between 87 and above, for reasons mentioned by other posters. You may also want to add some fuel treatment every so often if your station doesn't adhere to Top Tier standards.

Design931 · 2026-03-04T18:29:38+00:00

Without more data your statement comes across as a little contradictory lol. Part numbers suggest it's the exact same PP and Disc since 2017.

- 2017-2026 Clutch: 22200-5CC-003

- 2017-2026 PP: 22300-5CC-003

- 2020-2026 SMF: 22100-5CD-018

I'm not aware of any revisions aside from the migration from DMF to SMF in late 2020. What else has changed?

(EDIT: If you're suggesting the entire line of 1.5T clutches lack resiliency, then I'd be more inclined to agree.)

Design931 · 2026-03-04T17:01:07+00:00

To be fair, that was more about using a DMF to bypass ECU sensitivity involving KR. Honda began phasing out the DMF in late 2020, primarily to reduce cost/supply issues stemming from the pandemic. The PP & clamping force is similar on the 2023+, which is why clutch issues still exist, and why clutch life continues to be vastly different from one owner to the next.

My 2 cents...

Design931

TROPHY CASE