Hondata #4 reflash and "box" type intakes (Comptech or Mugen)

[vbb]

I've been thinking of switching from my V2 to either the icebox or Mugen airbox and have been reading a little about a "power dip" when running either of these with the #4 reflash. Right now, I love the way the reflash mates up to my V2... I put down the numbers in my sig with only these two mods on a hot and humid day, which was fine by me. Now, I may switch to either the Comptech or Mugen just because I want to try it out. The V2 sounds good, but it is just a little on the louder side for me.

Just wondering what kind of power changes I should expect... and I'm especially interested in any power dip around 5000 rpms which I've heard about. If someone has run this combo, great. If someone has dyno'ed these two together, that'd be even better.

And no... I'm not considering the CAI route even though I know they perform better.

[conradb212]

Originally Posted by vbeachboy

...Just wondering what kind of power changes I should expect... and I'm especially interested in any power dip around 5000 rpms which I've heard about. If someone has run this combo, great. If someone has dyno'ed these two together, that'd be even better.

And no... I'm not considering the CAI route even though I know they perform better.

I ran that combo and the observation originated with me, though others have experienced it as well. I should point out that I liked the Icebox, feel it is a well-designed quality product that has a substantial improvement over the stock airbox, and that othes may not have the problems I encountered. That said, the below compilation of dynos shows the issue. You can see the dip just before VTEC. The second dyno run was with Hondata #4 and Icebox. All dynos were done on Comptech's Dyno Dynamics.

[CarLo]

I thought your getting another car? but get the comptech

[vbb]

Conrad, thanks for posting the dyno overlays. I notice a few things that are interesting. First, it looks that the icebox + Hondata #4 combo only gained you about 8whp over stock at the peak, although the midrange you gained about 16-18whp (which is very nice). The CAI + K-Pro however looks like you got about a 24whp gain in the mid and close to a 16whp gain peak over stock. Were you running the preloaded CAI cal when you had the K-Pro and CAI only or was that a full tune?

Man, I do need to get K-Pro at some point!

Anyway, I would guess that the Comptech or Mugen box would add comparable numbers to my V2 when mated with my Hondata #4. That I would be okay with. The dip in HP is definitely there on the graph... but was it enough to be noticeable when driving? It looks like the dip is immediately before VTEC engages with the #4 reflash, so maybe that had something to do with it?

[park83rsx]

Originally Posted by vbeachboy

Anyway, I would guess that the Comptech or Mugen box would add comparable numbers to my V2 when mated with my Hondata #4. That I would be okay with. The dip in HP is definitely there on the graph... but was it enough to be noticeable when driving? It looks like the dip is immediately before VTEC engages with the #4 reflash, so maybe that had something to do with it?

Also, keep in mind that the Icebox will give you colder air than the V2.

[conradb212]

Originally Posted by vbeachboy

Conrad, thanks for posting the dyno overlays. I notice a few things that are interesting. First, it looks that the icebox + Hondata #4 combo only gained you about 8whp over stock at the peak, although the midrange you gained about 16-18whp (which is very nice). The CAI + K-Pro however looks like you got about a 24whp gain in the mid and close to a 16whp gain peak over stock. Were you running the preloaded CAI cal when you had the K-Pro and CAI only or was that a full tune?

It is not an entirely fair comparison because the Hondata/Icebox dyno was done at only about 1,000 miles whereas the K-Pro/CAI dyno was done at around 5,000 miles when the engine was nicely broken in. Also, by that time I had the Powergetter, IMG, and considerable experience in tuning with the K-Pro. The peak gain over stock probably was even more as that dyno run didn't go all the way to redline.

You did notice the large midrange gain, and that is really the most beneficial aspect of Hondata. The lowered VTEC, combined with a good tune, totally transforms the car in everyday driving. There is just so much more torque. As for VTEC points, you probably noticed the black dots on each of the runs. Those are the VTEC points.

The dip in HP is definitely there on the graph... but was it enough to be noticeable when driving? It looks like the dip is immediately before VTEC engages with the #4 reflash, so maybe that had something to do with it?

It was definitely very noticeable in my car, and at the time MMmotornutz, who had an almost identical setup, also noticed it. I probably would have happily stayed with the Icebox had I not done a dyno with the CAI at the end of a Icebox tuning session. The results were compelling enough to switch. In any case, the problem is not with the Icebox; it's just that Hondata 4 was tuned for use with a CAI.

[vbb]

Gotcha.

Yeah, Hondata #4 really makes quite a difference in the midrange, there is no doubt at all about that. I remember (as all of us probably do) the first time I installed the reflash and took it on the road for a test.

I don't want to run a less than optimal system in having the icebox and reflash. Well, I guess I already am because I have Hondata mated to a V2 and not to a true CAI. But I'm thinking that rather than switching intakes, I might just go ahead and get K-Pro and see what I can extract out of my current mods. Then I can get the icebox or Mugen box and tune out any anomalies in my power curve. I'm adding the comptech street header tomorrow.

[vbb]

Originally Posted by park83rsx

Also, keep in mind that the Icebox will give you colder air than the V2.

Yes, that is another bonus. But like I said in my previous post, I think my money would be better spent just getting the K-Pro first, and switching intakes later.

[park83rsx]

Originally Posted by vbeachboy

Yes, that is another bonus. But like I said in my previous post, I think my money would be better spent just getting the K-Pro first, and switching intakes later.

Yeah, definitely do the K-pro. Then you really get to see the difference in IATs.

[conradb212]

Originally Posted by vbeachboy

I'm adding the comptech street header tomorrow.

I have that one as well. When Comptech installed it they wanted to do a baseline and then a run with the street header, to see actual power gains. Unfortunately, that day the dyno had a problem and so we never got that answer. I am still glad I got the street header even though it probably doesn't bring much. I did compare the stocker with the Comptech header, and the Comptech is much better made, smoother curves, and has slightly larger pipes.

[vbb]

Originally Posted by conradb212

I have that one as well. When Comptech installed it they wanted to do a baseline and then a run with the street header, to see actual power gains. Unfortunately, that day the dyno had a problem and so we never got that answer. I am still glad I got the street header even though it probably doesn't bring much. I did compare the stocker with the Comptech header, and the Comptech is much better made, smoother curves, and has slightly larger pipes.

Well I can't provide a comparison for a stock RSX-S vs. one with just a Comptech Street header, but I do plan on getting re-dyno'ed after I install the header on my setup. I'm doing this partially because I haven't seen a good graph in here representing the gains (if any) that can be had from just adding a street header. We all know race headers are where it is at performance wise, but for some of us a race header isn't really a viable option. I plan on doing the street header tomorrow, along with an oil change and cleaning my air filter, and then hitting the dyno at the end of this month. As you can see in my sig, I put down 187.5/140.9 SAE with just the Hondata #4 and V2. With the overlays, I should be able to see where the street header benefits my setup, if it does at all.

I'll post up when I get it all done.

And then I'll get K-Pro