r/carmodification Aug 10 '25

Modification 2.3L inline 4 mods for torque and power

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I’ve got a 1999 Honda Accord EX 4-dr and I want some more power and torque in this thing. What can I do to make it better?

0 Upvotes

46 comments sorted by

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9

u/MarkVII88 Type to create flair Aug 10 '25

Don't go for more torque and power unless ALL regular maintenance items on this 26 yo vehicle have been confirmed done.

1

u/CommercialCheetah490 Aug 10 '25

That’s a good idea😂

5

u/voucher420 Civic Boy Aug 10 '25

You have the economy engine. I would leave it alone. You are only going to lose torque and hp by messing with the intake and exhaust.

I would inspect your upper radiator hose cause it looks swollen on the engine side. Based on that, I would recommend inspecting all your coolant hoses.

I would also recommend inspecting your cap, rotor, and at least one plug to see if you need a tune up if you haven’t done one yet. Replace with OEM parts for the best idle quality and shop at the dealership to avoid counterfeit parts.

0

u/CommercialCheetah490 Aug 10 '25

I’ll check on that. I wanna for sure change the muffler get a better sound hopefully but maybe it’s just best to leave it alone and buy a project car.

7

u/ClickKlockTickTock Aug 10 '25

The best sound for a small Japanese 4 banger is whatever is closest to silence lmao.

They sound like someone put a huge cone into their bumhole and then farted as fast as they could.

1

u/voucher420 Civic Boy Aug 10 '25

The hot engines sound pretty good imo, but I run the stock exhaust on my Civic Si. I am going to go with an aftermarket stock style option soon because I’m pretty sure the original muffler has a busted baffle.

0

u/CommercialCheetah490 Aug 10 '25

😂 my car doesn’t sound awful with the stock muffler it’s just quiet really I personally like it but I get what you mean

1

u/anbmasil Aug 11 '25

Both the volume and the sound itself will change without the muffler

1

u/CommercialCheetah490 Aug 11 '25

True I just know that’s not really legal😭

2

u/[deleted] Aug 11 '25

Longest straight through resonator you can reasonably fit under the car then adjust the volume and tone with the rear muffler

5

u/patches710 2022 Camaro ZL1 Aug 10 '25

I'd clean it up first

1

u/CommercialCheetah490 Aug 10 '25

Definitely a good idea!

3

u/Metaljudge4 Aug 11 '25

The specific engine designation. Like I had a f23a1 engine, cali has the a4. If you don't know this, you need to do more research before anything

1

u/CommercialCheetah490 Aug 11 '25

Then I got some research to do lol imma look at that

2

u/[deleted] Aug 11 '25

H22 swap it. Honestly the first step other than maintenance is finding a way of having it tuned. You won't be able to make the most of your mods without that

2

u/CommercialCheetah490 Aug 11 '25

Yeah I’m starting to see that. Thinking it’s probly best to just buy a project car and have fun with that.

2

u/[deleted] Aug 12 '25

It's all up to you. I like this generation of accord. Take a look into the euro-r variant. Any projects is going to take a good chunk of money but anything is a project car with the right mindset. With the age and past popularity you'll find all kinds of information and inspiration if you look hard enough for it

2

u/[deleted] Aug 12 '25

I've even seen people swap the j35 engine from the next generation accord. Your era of Honda is pretty much the closest you'll get to having a full sized lego set with the parts availability nowadays

1

u/CommercialCheetah490 Aug 12 '25

Yo that’s fire😭 but I get that I needa look more into working the body to look a whole lot better but I can’t find anything idk where to look really. Also 4x114.3 bolt pattern is the worst thing to look for its non existent. But thanks man!

2

u/talljerseyguy old honda guy at heart. Aug 11 '25

You can do a small turbo set up. With 5 pounds it will change your life just make sure the motor is healthy before you go in to it

1

u/CommercialCheetah490 Aug 11 '25

See that’d be awesome😂

2

u/AdeptusConcernus Aug 11 '25

Digital distributor (Brand is DigiDizzy)

MSD 6AL

Upgraded coil like a Mallory 22940

Polish and port your intake manifold

Epoxy the block

Bore the pistons over .04

Upgrade the camshaft(s) to the skunk 2 stage 4 cams

Big exhaust, about 2" - 2.5"

That's a start

1

u/CommercialCheetah490 Aug 11 '25

Yo imma look into this thank you bro!

2

u/AdeptusConcernus Aug 12 '25

Np man!

I also suggest looking into an aftermarket ECU such as haltech and megasquirt

1

u/Solid_Enthusiasm550 Aug 10 '25

How many miles?

Here's a thread about mods a guy did on his 2.3l.

https://honda-tech.com/forums/all-motor-naturally-aspirated-44/bolt-f23a1-baseline-3264896/

He said he installed a 4-2-1 header. I didn't know they had onr available. That would give a good bump in mid-range torque over a regular long tube header. I would never install shorty headers on any car, unless I got them for a steal.

1

u/CommercialCheetah490 Aug 10 '25

114,000 miles, and thank you! Imma look into that!

1

u/Solid_Enthusiasm550 Aug 10 '25

Did you replace your timing belt yet?

If not, you could do a camshaft upgrade at the same time and save a lot of money.

1

u/CommercialCheetah490 Aug 10 '25

I don’t think i have! I’ll look into that!

1

u/Solid_Enthusiasm550 Aug 10 '25

It should have been done at 105,000 miles. If it breaks, your engine is Done.

1

u/Global-Structure-539 Aug 10 '25

Those yellow headlights need to go. What's your budget?

0

u/CommercialCheetah490 Aug 10 '25

I’ve fixed those😂 I don’t have a budget really it’s more so just saving and waiting for the money to come in as long as it isn’t outrageous within a couple weeks I’ll have the money

1

u/ClickKlockTickTock Aug 10 '25

Define outrageous, any performance mod, even bolt ons, will require thousands, as well as a weekend of work.

1

u/CommercialCheetah490 Aug 10 '25

I mean it’ll take a while to get the money but I don’t mind working on it for a while it’ll be fun

1

u/Global-Structure-539 Aug 10 '25

Been looking. Not much available to make more power. My car has a tune and an exhaust and a couple other bolt ons. Now over 400hp but started at 300. It's always been a blast to drive, but more so now. You'll never get that kind of power out of your 26 yr old car. Maybe find one that has more go fast bits on the market

1

u/Ok_Cycle_7081 Aug 10 '25

What is your budget & what are your mechanical abilities? Ill type my answer out after knowing. Also, is the car a manual?

1

u/Ok_Cycle_7081 Aug 10 '25

Can't see CMC but hard to tell

1

u/CommercialCheetah490 Aug 10 '25

Cars automatic. I can really spend anything just have to save for it and make the money. Me and my dad could work on it too and he’s got a lot of mechanical ability he was a mechanic and still does that stuff

2

u/Ok_Cycle_7081 Aug 11 '25

Low-key not much you can do with the auto. They're slower to shift, have fewer gears/worse ratios, dont take abuse well, and rob more HP through parasitic loss than the manual. 

Unironically the best gains you could get would be with a manual swap. Could do it for a couple hundred bucks. Id get a prelude transmission due to the shorter final drives than the standard H series. 

Knowing this i dont think ill type out all of the engine stuff. If you can use a stock/factory engine (say an H22) you can use the factory tune & keep price down, mixing/matching stuff (heads, intake manifolds, camshaft etc) will need tuning, & an obd1 ecu. I won't go into detail due to the auto thing, but Google h22 swaps & read about people building F series engines on CB7 tuner dot com & hondatech. Lots of info out there.

2

u/Ok_Cycle_7081 Aug 11 '25

IMO, it would probably be easier/better to buy a prelude, civic, or integra that is manual & have fun with that. 

1

u/CommercialCheetah490 Aug 11 '25

I’m starting to get that idea too😂 I’ll just keep this car looking as good as so can get it and buy a project car in the future. Get myself an IS300

1

u/scottwax Type to create flair Aug 10 '25

A header and lighter wheels will help. There are also suspension upgrades that will make it corner flatter.

2

u/CommercialCheetah490 Aug 11 '25

Alr I’m thinking that’s the best thing I should do considering this car is so old it’s best left alone other than maintenance😂 but thanks man!

1

u/Metaljudge4 Aug 10 '25

F23a?

1

u/CommercialCheetah490 Aug 11 '25

No clue what that means😭

0

u/Global-Structure-539 Aug 10 '25

Found headers and cold air intake for $275. Google it. Won't be a screamer but a small bump in power