Highest F23 Dynos and 1/4 Mile Times
I wouldn't say the F23 block could hold 350whp safely. With a bad/no tune, you could blow the motor at ~200whp. With really good tuning, it can be achieved, but I would consider it a ticking bomb regardless of how good your tune is.
Nice, where is vtec set at? It looks like you have it tuned very similarly to my old set up that made just over 400whp. Is there a nasty hole tuning wise at 4000-4500 rpm?
Naturally Aspirated:
1. AFAccord - 176.1whp/170.1wtq
1. AFAccord - 176.1whp/170.1wtq
- Bisimoto Level 2 Cam
- Bisimoto valve springs & retainers
- Skunk2 TB
- H23 Intake Manifold
- eBay Header with collector mod
- 2.5" Custom Exhaust
- P61 OBD1 ECU with OBD2-OBD1 Engine Harness
- Milled head with mild port work
- H23 Trans
- AEM Cam gear
Should be a couple more fellas finishing up their all out NA builds sometime soon as well. They're both aiming for 200+whp. We'll see!
Very Nice! I take it that your VTEC is set @ 2200 ?
I'm going to get mine tuned in two weeks.
Hoping my numbers will be close to yours!
Did it "wake up" since the tune?
I would love to see some times!
I'm going to get mine tuned in two weeks.
Hoping my numbers will be close to yours!
Did it "wake up" since the tune?
I would love to see some times!
I no longer use VTEC, I locked my rockers together. The tune made it run much better, but it still drops power like a rock above 6k, which it didn't do on the stock cam. I still need to dyno tune, as this was just 3 pulls.
I disassembled the rocker assembly and adjusted the dowel pins so that all three rocker arms are locked to the center rocker arm, exactly what happens when VTEC engages. Now the valvetrain is mechanically in VTEC all the time.
why did you do this? what are the pros and cons to doing this?
It's a bit of a mixed bag, and really just a matter of opinion. On the F22/23 this doesn't cause any harm because the VTEC lobe isn't extremely aggressive in comparison to the primary lobes. On a DOHC VTEC engine like an H22, it would be much more difficult to make the car idle correctly and run smoothly at lower RPMs on just the VTEC lobes since they are better suited to running between 4,000 and 8,000rpm instead of the F's 2,000 to 5,000rpm range.
Pros:
- nice lopey idle
- cam is always on a roller, not a pad
- less moving parts in the valvetrain
- draws a lot of attention to hear a 4cyl with a 'cammed' exhaust note
Cons:
- idle not very smooth, especially with aftermarket engine mounts
- emissions will suffer since the VTEC lobe isn't as efficient at low rpms
- fuel consumption might increase a negligible amount if you idle your car for long periods
- draws a lot of attention to hear a 4cyl with a 'cammed' exhaust note
It's a rather insignificant modification. It doesn't significantly affect performance, if at all, and it doesn't make the car any more difficult to drive. However, I would NOT suggest doing this unless you can tune the car to correctly run this way (ie. stock ECUs/Piggybacks stay away). The timing and fuel trims will need to be touched up to make the car run smoothly at part throttle and for smooth transitions on/off throttle.
Nothing that can't be regained from aggressive ignition timing, which the F seems to love. The first time I dyno tuned, we set the stock cam to 5 degrees retard in order to bring the power band up, which of course pulled power from the low end. With timing adjustments, the tuner was not only able to recover all power lost from the cam adjustment, but actually gained ~4whp across the band from idle to 3k rpm.
Since the VTEC crossover is so low on F23's, there's not much low-end to lose anyway. Just driving around town, you're running on the VTEC lobe by 2300rpm just in stock form.
Pros:
- nice lopey idle
- cam is always on a roller, not a pad
- less moving parts in the valvetrain
- draws a lot of attention to hear a 4cyl with a 'cammed' exhaust note
Cons:
- idle not very smooth, especially with aftermarket engine mounts
- emissions will suffer since the VTEC lobe isn't as efficient at low rpms
- fuel consumption might increase a negligible amount if you idle your car for long periods
- draws a lot of attention to hear a 4cyl with a 'cammed' exhaust note

It's a rather insignificant modification. It doesn't significantly affect performance, if at all, and it doesn't make the car any more difficult to drive. However, I would NOT suggest doing this unless you can tune the car to correctly run this way (ie. stock ECUs/Piggybacks stay away). The timing and fuel trims will need to be touched up to make the car run smoothly at part throttle and for smooth transitions on/off throttle.
Since the VTEC crossover is so low on F23's, there's not much low-end to lose anyway. Just driving around town, you're running on the VTEC lobe by 2300rpm just in stock form.
I have a 2 1/2" exhaust to a 60mm skunk 2 lol. To a 3" axleback, I can probably pick up some power by changing my exhaust lol.
Its fun to drive, but will kill tires at low speeds.
Here's my last print. 
98 Accord - F23A4 ULEV stock NA Motor on Webcamshaft, V2 CAI, Adj. Fuel Press. Regulator, DC Header, an UR-Ultra Crank Pulley tuned on AEM Management System, and WSII Exhaust w/a Cat!
Also: H23 Trans. Swap & Exedy Stage 1 Clutch.
I had changes done to AEM unit that affected driveability and tuning a bit; also had catalytic converter removed, an aluminum flywheel and 6 puck clutch installed after this test but never dyno'd car again since. I'm sure it's above 160 by now but we'll have to wait until next dyno session.
153.8 whp/152.7wtq.


98 Accord - F23A4 ULEV stock NA Motor on Webcamshaft, V2 CAI, Adj. Fuel Press. Regulator, DC Header, an UR-Ultra Crank Pulley tuned on AEM Management System, and WSII Exhaust w/a Cat!
Also: H23 Trans. Swap & Exedy Stage 1 Clutch.
I had changes done to AEM unit that affected driveability and tuning a bit; also had catalytic converter removed, an aluminum flywheel and 6 puck clutch installed after this test but never dyno'd car again since. I'm sure it's above 160 by now but we'll have to wait until next dyno session.
153.8 whp/152.7wtq.





