Maxthepersonz

What size are the injectors?

Uncle Dave

RDX Injectors are OEM Honda rated at 410cc

raverx3m

iTrader: (1)

are those RS machines or oem pistons?

Rocket

What is commonly over looked and not well understood is that the IM makes as much and usually more of a difference in power than cams. These two components work hand in hand. Get the combo wrong and your down 10 to 15 percent.

PRE's latest customer didn't listen and want with an ITR style His fuel numbers, ie, power is way down

Charlie Moua

iTrader: (3)

IMHO from what I know of the build (limited lol), the order of importance is:

1) engine builder
2) headwork
3) cams
4) IM


it was already a stout motor before the IM, sure the peak numbers are nice thank to the modified PX IM, that's just really icing on the cake. Change out the headwork, different engine builder and you'd probably get a bunch of guys making sub 225whp (which isn't bad, but not great either).

I think the point of the thread was to show what can be done when you know what your doing. Not so much of a "cookie cutter" build.

Uncle Dave

Pro2 cams are very sensitive to intake tuning.

Maxthepersonz

This is good to know.. I have a BLOX gen 1 intake manifold, and am building an engine very similar to this one at the moment. Should I go with the Pro2's or something else? They're expensive but usually you do get your moneys worth.

slowsleeper

Pistons are RS/Safety 82mm pistons. I believe only over bore size OEM pistons come in is 81.25mm.

^Truth, power comes on too late and out of engine's efficiency range.

Uncle Dave

The manifold used on this build should give you a very good idea as to what to use.

Rocket

I'll keep repeating, PX manifold is the cat's meow. It's got the proper-length runner to make power more power than the weak-*** ITR style IM's.

The PX is like bruce, lean and mean. The ITR-style IM is like the homer-looking Norris character, good but, but ultimately pales in head-to-head competition. FF tp 2:01 for the proverbial, "cat's meow."


The winner of the WD-40 shootout used TWM's that have about the same length runners as the PX, and they stomped the competition by 20+hp using shitty crower cams.

Short-runner IM's were a band-aid fix when cams were with limited duration.

Charlie Moua

iTrader: (3)

haha

Black R

Rocket, the performerX in the OP is modded with shortened runners though...

Rocket

True. But the unmodded PX made better power. The high HP-run was done in 4th gear.

If you guys keep doing the same thing, you'll make the same or less power.

The WD-40 shootout shows that 3 motors are within 2% in power when using the shitty ITR-style IM. If you do 7% transmission loss on the 260 flywheel HP, these elite-built 2.0L made 242whp. These elite motors had CNC heads, trick oil control, trick cams, elite tuning (JG is the best tuner on the planet). The average Joe is going to have a hard time doing any better.

Study the data/results, and learn, folks.

DDTECH

LOLWUT.. no. Come on now really..? lol.


There's another thread of testing done by mikeyspec that shows some nice results and r/d.


https://honda-tech.com/forums/all-motor-naturally-aspirated-44/kingmotorsports-modded-performer-x-thread-2873074/ is a good thread to read.

Rocket

So the longer-runners on WD40 shootout winner hurt its power?

Runners that are ITR and shorter are ideal for being 20+whp down for 2nd, 3rd, and 4th place .

FYI, JG was Bubba's (of Horizon Motorsports and Do-it Dyno fame) tuning mentor. What more can be said on this topic? And I learned from Bubba, via osmosis, when I used to help him with Horizon Motorsports projects.

DDTECH

Its a bold statement..rocket. I know bubba, he's a good friend, and does do outstanding work. He also did a recent test with my cams. But to say he's the best on the planet when guys around the world do just as good work is just.. alittle vague.

I don't know exactly which test you're looking at, if you're quote the test that super street did, that's like what 3-5 + years old? There's been a lot of advancement since then in tuning, manifold tuning, cam tuning and header tuning.

Also, again, Runner length is only one part of the equation, plenum sizing, spacing.. etc. I will tell you, from "personal" testing, I made more power, and ran fast 1/4 times with a modded victor manifold over ported 52MM TWM itbs and 50MM OBX itbs. Which is why I sold the itbs and went back to a custom manifold.

Attached is a pic of the manifold going on the car now. Tapper runners is also a new thing..that I've been wanting, and AFI was the only company to be able to offer it.

Also another thing, Better developed injectors, we're seeing 10+whp gains from injector swaps alone.. Look @ Koz's results, I think he had over 15+whp.. There's a lot that has progressed since that test rocket.
My buddy James over @ bmc told me this is the general length for powerband
9" primary up to 8k
8" primary for up to 9k
7" primary up to 10k
6" primary up to 11k

JeffBro

I am starting to believe runner length is the critical factor. Very few people outside of the high end racing crowd seem to be aware of it. In formula 1 runner length is huge. They have been using custom manifolds built to specifically change the runner length based on the race track for a number of years now.

Uncle Dave

As soon as you cam a B series engine the PX in unmodified form will let you down.

DDTECH

Its important.. and has been over looked for years.

Rosko did a good write up on manifold length here
https://honda-tech.com/forums/showth...2#post48948862

honduh_head

bad link?

DDTECH

already know.. lol..


Also, i'm definitely not trying to argue, but just stating some information that should be known.

honduh_head

Every engine reacts differently to parts, there's no way you can make a mass produced intake or exhaust/header that will cover all aspects of how the engine will make power. I would say skunk2 has the best formula, considering they have the "tuner", the "pro" and the adjustable "alpha" to cover all power bands. they may not make the best power in the world, but the ideas behind it are genius. sadly in this day and age, there's not enough money in this community for a truly "perfect" manifold to be designed, cause no one with a honda (sans nsx guys) will pay the R&D needed to find the perfect design.

mines pretty close though



jk

Rocket

ITR length runner sucks. Look at the WD40 shootout.

EF9PR

Remember this test https://honda-tech.com/forums/all-motor-naturally-aspirated-44/intake-manifold-test-results-1-8l-edelbrock-itr-ibspec-take-look-revised-2869703/. I will test the PX(unmodified) with some custom DDTECH cams in my 81.5 b18c. The PX with pro2s in my engine hold the same HP from 7,500-9,000rpm. Slowsleeper help me a lot on the tuning and Derek on the new cam specs.

Uncle Dave

People dont take Runner length and shape into account and buy the wrong cams so nothing matches up and torque/power is never what they want then the head flows wrong and everything keeps going around and around then they post up here asking whats wrong with there setup and this product is crap it just never ends.