400 WHP Build with Headroom – Smart or Pointless?

[beaterfl5]

Hi all,

I currently have an upgraded intercooler, inlet, downpipe, exhaust, and a Stage 2 Phearable tune. I’ve also got a Kuro+, Hondata flex fuel kit, and Hondata injectors on the way.

Out of curiosity—would it be possible to limit the HP to the low 400s instead of pushing everything to the max? My goal is to prioritize reliability and longevity, and I feel like 400 WHP is more than enough for a 4-cylinder engine. My thinking is that having all the supporting mods but running them conservatively would help preserve the engine and drivetrain long-term.

This is my first "tuner" car, so it's all new to me so forgive me if I sound like idk what i'm talking about haha. Would love to hear others’ thoughts or experiences with a similar setup.

Thanks!

Sponsored

 

[FL5alive]

Cancel the CanFlex and injectors and get the smaller Kuro. You can do low 400s on 93 with the stock fuel system all day safely with that set up and save a little money.

 

[nattypiso]

You can reach 400whp on stock turbo if you purchase a modified High Pressure Fuel Line. OEM line is pretty restrictive.. once the line is opened up, it will flow more without pulsing issues. Less stress for your stock fuel system.

If you’re wanting to just stick with low 400’s, I’d just go with CANFlex (I think E25-E30 is the sweet spot for your stock fuel system) and a modified HPFL. You’re not going to get your moneys worth out of a Kuro/MHI stage 2 honestly.

 

[Two Step Performance]

Cancel the CanFlex and injectors and get the smaller Kuro. You can do low 400s on 93 with the stock fuel system all day safely with that set up and save a little money.

This is the way to go. Put $2000 back in your pocket and also maintain a lightning fast spool.

The Kuro+ is great but if you aren’t going for 500+ it is overkill.

 

[Websitesdown]

You can reach 400whp on stock turbo if you purchase a modified High Pressure Fuel Line. OEM line is pretty restrictive.. once the line is opened up, it will flow more without pulsing issues. Less stress for your stock fuel system.

If you’re wanting to just stick with low 400’s, I’d just go with CANFlex (I think E25-E30 is the sweet spot for your stock fuel system) and a modified HPFL. You’re not going to get your moneys worth out of a Kuro/MHI stage 2 honestly.

This is the way to go. Put $2000 back in your pocket and also maintain a lightning fast spool.

The Kuro+ is great but if you aren’t going for 500+ it is overkill.

Which one of you two are correct?

 

[Two Step Performance]

Which one of you two are correct?

I’ll have to say that I’ve never seen an honest 400whp out of a stock turbo FL5 regardless of fuel type. I do believe it *might* be possible with an ethanol blend of some sort. However, if the OP wants any kind of “headroom”, this is not the way. The fuel system would likely be pushed to the edge of it’s limits - not to mention the turbo itself.

A Kuro on 93 octane can make 400whp VERY comfortably, even up to about 425whp before running out of fuel. You also end up with a much nicer power curve, as the factory turbo taps out well before redline and the Kuro will pull of the way to The top.

All that being said, I think the Kuro makes the perfect OEM+ Type R (or Type S). You are able to maintain the lightning quick turbo spool that Honda’s engineer’s intended, but still add a strong kick in extra power up top.

 

[Websitesdown]

I’ll have to say that I’ve never seen an honest 400whp out of a stock turbo FL5 regardless of fuel type. I do believe it *might* be possible with an ethanol blend of some sort. However, if the OP wants any kind of “headroom”, this is not the way. The fuel system would likely be pushed to the edge of it’s limits - not to mention the turbo itself.

A Kuro on 93 octane can make 400whp VERY comfortably, even up to about 425whp before running out of fuel. You also end up with a much nicer power curve, as the factory turbo taps out well before redline and the Kuro will pull of the way to The top.

All that being said, I think the Kuro makes the perfect OEM+ Type R (or Type S). You are able to maintain the lightning quick turbo spool that Honda’s engineer’s intended, but still add a strong kick in extra power up top.

That makes sense thank you!

 

[nattypiso]

Which one of you two are correct?

I guess different ways to get there, different solutions, different costs, same result.

I would assume that once you upgrade, like me, you’ll get that itch for more power. So if you go the turbo route, you’ll already have a something that’s capable of easily pushing 400+ but again, depending on your upgrades, your tune will eventually be needed to be toned down for your fuel system to compensate for that extra boost.

It also doesn’t hurt to have a good talk with your tuner as well. Derek Robinson is my tuner from IMW and I’m always picking his brain asking him questions about my build.

 

[beaterfl5]

I’ll have to say that I’ve never seen an honest 400whp out of a stock turbo FL5 regardless of fuel type. I do believe it *might* be possible with an ethanol blend of some sort. However, if the OP wants any kind of “headroom”, this is not the way. The fuel system would likely be pushed to the edge of it’s limits - not to mention the turbo itself.

A Kuro on 93 octane can make 400whp VERY comfortably, even up to about 425whp before running out of fuel. You also end up with a much nicer power curve, as the factory turbo taps out well before redline and the Kuro will pull of the way to The top.

All that being said, I think the Kuro makes the perfect OEM+ Type R (or Type S). You are able to maintain the lightning quick turbo spool that Honda’s engineer’s intended, but still add a strong kick in extra power up top.

I think this is what i'll eventually end up doing. Just stick with the regular kuro and a proper tune, skip the fuel upgrades for now. Thanks for all the input. I just gotta shoot yall an email to yall to cancel some of my preorders though

 

[Two Step Performance]

I think this is what i'll eventually end up doing. Just stick with the regular kuro and a proper tune, skip the fuel upgrades for now. Thanks for all the input. I just gotta shoot yall an email to yall to cancel some of my preorders though

No worries, our support team and can help get things straight for you. We are happy to help!

 

[So_si]

Would it be possible to hit 400whp with out a down pipe? I have hvi, tip, intercooler, charge pipes, mbrp exhaust which comes with front pipe?

 

[Unity Performance]

The easiest recipe for the 400's is the following, and we proved it nearly 2 years ago

- Kuro
- DP
- Intercooler
- Hondata + custom tuning



430whp/387wtq. We've used this Dyno for all the Unity builds, and the numbers it provides are very consistent with what DRob, TSP, JSR, and others have posted for Kuro.

Intake, Inlet, heck even a filter change are all optional. I've thrashed the car at track days before, and would get 12 minutes instead of 15 of consistent lapping. There were no cooling mods done to the car at that time to help with Oil and Coolant Temps, so I expected shorter sessions. Rad upgrade, hood vent, lower cooling plate, oil cooler, water/coolant mix would mostly remedy the inherent overheating issues that affect the platform when tracking.

On the street the Kuro just gets up and goes. No lag, nothing special other than recommended 5W30 weight engine oil.

 

[nattypiso]

Would it be possible to hit 400whp with out a down pipe? I have hvi, tip, intercooler, charge pipes, mbrp exhaust which comes with front pipe?

When it comes to the OEM downpipe, it is the most restrictive part of the car other than upgrading to flex fuel system. I’d recommend upgrading it, I’m currently using TSP’s downpipe.

 

[egxflash]

The easiest recipe for the 400's is the following, and we proved it nearly 2 years ago

- Kuro
- DP
- Intercooler
- Hondata + custom tuning



430whp/387wtq. We've used this Dyno for all the Unity builds, and the numbers it provides are very consistent with what DRob, TSP, JSR, and others have posted for Kuro.

Intake, Inlet, heck even a filter change are all optional. I've thrashed the car at track days before, and would get 12 minutes instead of 15 of consistent lapping. There were no cooling mods done to the car at that time to help with Oil and Coolant Temps, so I expected shorter sessions. Rad upgrade, hood vent, lower cooling plate, oil cooler, water/coolant mix would mostly remedy the inherent overheating issues that affect the platform when tracking.

On the street the Kuro just gets up and goes. No lag, nothing special other than recommended 5W30 weight engine oil.

what about if it's a catted downpipe? Looking specifically at the @Two Step Performance high efficiency dp.

 

[Two Step Performance]

what about if it's a catted downpipe? Looking specifically at the @Two Step Performance high efficiency dp.

The 5" catalyst we use is rated for up to 1000whp. It's the same one we use in our 577whp FL5 with the Kuro+.

Sponsored