BADGUYNY

iTrader: (1)

If anyone is close to all off the shelf parts it would be DP racing

KeseK24RSX

If you go to 30 secs in the video & pause it. You'll see that the engine is nothing special. JG manifold unported, 70mm TB, Stock Distributor, NGK wires, Skunk2 Cams, Full-Race Top mount manifold, 72mm Garrett Turbo.

http://www.youtube.com/watch?v=kCmmzgVppn0

-Marquis
-KMOD Performance

Hyper16-Johnny

Was this with all OTS parts?

miller

BMC manifolds have come a long way. The quality these days is top notch and the power is there to prove it.

OTS parts! Haha. You guys crack me up. OTS parts become off the shelf parts after the development has been done by others. A "consistent" 8 second car can be bult these days without issue depending on the class and weight of the car. Those 1/2 8 second passes a season while hurting 4/5 engines really doesnt count. Hhahaa

miller

BMC manifolds have come a long way. The quality these days is top notch and the power is there to prove it.

OTS parts! Haha. You guys crack me up. OTS parts become off the shelf parts after the development has been done by others. A "consistent" 8 second car can be bult these days without issue depending on the class and weight of the car. Those 1/2 8 second passes a season while hurting 4/5 engines really doesnt count. Hhahaa

acura_b18c1

hmm 2 questions for ya :

1. on a 2L with a decent flowing head and cams that are on the big side, how would the setup react to a drag plenum with 8" runners vs a smaller plenum with the same 8" runners vs say OTS IMs such as the skunk2 pro or performerX?

2. u said power drops off early (around 8.5k rpm) with 8" runner .. arent there ways to extend it a littler further, such as around 9-9.2k rpm with say a cam with more duration?

BMCRace

1.
Its very hard to tell you exactly what would be the best. What rpm are you revving this motor to would be the biggest question and next is where would you want the majority of your power?
The 2 ots manifolds you described there would be great candidates for that motor assuming you weren't pushing more than 8500rpm and were really only ever in the 235-245whp zone to begin with. My manifold might be able to bump you an extra 10hp due to better airflow, smoother primaries and plenum. This is all very subjective though to the exact goals of the setup. For instance, if I told you I would give you an extra 10whp, but you have to chose a 2000rpm band of where it would be. Would you want it mid range, low end, or high end?

There honestly is no one size fits all, that's what makes this a tricky game. And the glory of it is, as soon as you mod your engine, everything gets thrown out the window and you need a new manifold to match the new setup.




2.
The Street plenum with an 8" primary would have it dropping off around 8.5k but a drag plenum would hold power to 9000-9200rpm exactly as you are asking yes. However this larger plenum would sacrifice responsiveness and low end power. The mid range would be minutely sacrificed, hardly noticeable, but still noticeable.. This would be a better application for a Street Turbo car who wants good midrange and Great topend power.

B23-Vtec

Hey guys my name is Ricky Taylor i have a small shop call InFamous MotorSports im in nc. I have a old build on here allmotor section. I am in the process of building my new motor. Was wondering if you guys could give me some input on if you think your manifold would denifit me. My old setup was a 95X86 13.1 b20 block Rlz b16 head SK2 T3 cams victor x and a dh-racing 83mm tb 3.5" cold air and smsp custom 3" header. It made 275whp on RLZ dynopak 3000 went 6.9 at 105 1/8 mile. My new motor is 98X86 16.1 eveything else the same might change the cams up for some of allmotors custom cams. Thanks for the help

acura_b18c1

my setup right now is simple. :
2L 13.1:1 comp E85
Portflow head Skunk2 Pro2 cams
TWM 52mm ITBs , Big tube replica header

the car makes 241whp and 163tq. the rev limit is at 9000 but power drops at around 8400rpm. The car is a street car that is daily driven and goes to the drag strip on the weekend. I want to gain some power between 6000-9000rpm because thats where the rev limit is at and where the rpm drops to. what are your recommendations?

GodFather of Boost

Not sure but is this a jab at me??

miller

No love! It's a jab at the guys who say they have 8 second cars but can only pull it off 1 or 2 times a season while tearing up engine after engine. Hahah

rmercado

i love mine....

99black_em1

good read. so for a setup making about 245whp and revving to about 8.5k-9k, theres no real benefits switching from a OTS IM to the BMC? just wondering , i saw an old thread in the all motor section with testing by Profunction. I think they swapped over from a ported ITR IM to Kinsler ITBs and gained like 30hp+. This was not specific to one area, gains were everywhere especially the top end. Is this because its an ITB, and gains like this wont happen on an IM?

2k.civic.si

goes to show you the itr manifold was way undersized for that engine.

BMCRace

Exactly^^


A bigger, or higher cfm flowing intake manifold will only EVER make more power if the engine needs the greater volume and airflow.

Similar senario that guys run into all the time:

You have a pretty much stock bottom end and then get a top dollar race head and cams. You make little to no more power than stock, why? Because unless your engine has been increased in size, increased the compression ratio either statically (pistons) or dynamically (boost), or is revving to higher rpm's, there is little need for more airflow since the overall engine is still more/less the same.

This goes the same for the intake manifold.

Unless the engine actually needs a bigger plenum (more displacement, boosted, or higher rpm requirements) and subsequently needs greater cfm flow capabilities (ported head, displacement, big lift cam, boosted, etc) then there will be little gains needed.

The guy picked up alot more power with the itb in that instance because the engine needed more airflow.

Hypothetical example:
If your engine makes ~250hp at ~275cfm, but you use an intake that only flows ~250cfm then you will be making less approx 10% less hp than your 250 that you have potential for.

Now lets say you increase the cfm capabilities of the engine to 300cfm and give the engine the need for the more airflow (rev a little higher, bigger displacement, or higher compression ratio) and you are sure to run an intake that will flow what your engine requires (300cfm).
Now you have managed to pickup approx 10%+ more hp and are making ~275hp...

Guys see this all the time when they have a built drag all motor engine and do a stroker kit but fail to increase the airflow through the head via better porting and higher lift cams. The engine ends up making the same hp because hp is cfm dependent, it just makes the power at a lower rpm then the engine fails to build more hp and is thus maxed out on the cfm capabilities to the headwork.


So footnotes:

Intakes will only ever make more power if the engine needs it.
Head work will only ever make more power if the engine needs it.

The way you make the engine "need" these things is:

Increase the displacement, bore/stroke = more air requirements to run the motor = greater airflow requirements of the intake/exhaust track (intake mani, head, cam, exhaust mani)

Increase volumetric efficiency of the engine, this is done by increasing the compression ratio either statically (pistons, smaller combustion chamber) or dynamically (boosted application, nitrous). Again this will require an increase in the entire intake/exhaust track to see full potential

Increase the rpm range, it takes A LOT of airflow to maintain trq in the greater rpms. However if your bottom end can handle the piston speeds, and the intake/exhaust track can flow enough air, it is a amazing substitute for power over a greater displacement setup. Ever wander how a 600cc gsx-r motor manages to make 115hp? Big airflow. Hell even a couple Honda drag guys have learned this trick also and are making alot more power than they had the previous sessions.

99black_em1

I'm pretty sure the ported ITR beat the VictorX on the same test, the lost to the Kinslers by 30+




- another good read BMC. I'll have to take my time to read it

99black_em1

ok so I'm jus goin to use that test that Profunction did as an example. it's a simple 2L B with 13.1:1 comp ( has the size and compression upgrade ). uses Pro3 cams and Portflow headwork. He tested the Ported ITR to a VictorX and lost hp so can't really say the ITR is undersized. He also tested the ITR against the AIR carbon fiber IM with similar results. Then, he tested the Kinsler ITBs and jus instantly gained everywhere!

bottom line: can an intake manifold offer those kinds of gains. why or why not? I'm curious because I've never seen an intake manifold beat another everywhere by this much. Also, let's keep this discussion under 9000rpm because Profunction kept 9000rpm in all of his tests.

2k.civic.si

if they went from the ported ITR to the kinsler itbs and picked up 30+ hp then ITR manifold was extremely undersized.

Black R

Got a link to his test?

BMCRace

Comparing a itr manifold vs a vicX is comparing apples to oranges.

A vic x uses a 7" primary, a 7" primary is a manifold that is meant for hp up to 10,500rpm. The itr (I'm not 100% positive on this*) uses roughly a 9" primary which would mean it is setup for rpms up to ~8500rpm.
When doing a dyno to only 9000rpm, and the vic x is losing compared to the itr, well this is quite obvious. You are not up in the vicX tuned powerband yet. This does not at all mean that the victorX lost power, it just means that the guys never revved the engine to where the victorX was tuned to show the power gain.

The ITB picked up a ton of power because it had a similar primary length and was thus tuned to the exact same rpms as the itr manifold. However the ITB significantly outflowed (cfm capacity) the itr and that's how it picked up 30more whp across the board.


I can make a dyno chart look however I want by tuning the primaries on a manifold. Consequently I can make any high rpm manifold look like doodoo on a dyno by simply not revving the engine to take advantage of its high rpm capacity. On the other hand I an make a low rpm manifold look like crud by simply revving the engine over hits tuned capacity.


This isn't 100% accurate but for this discussions sake it will do:

10" primary = ~7000-7500peak hp
9" primary = ~8000-8500peak hp
8" primary = ~9000-9500peak hp
7" primary = ~10,000-10,500peak hp
6" primary = ~11,000-11,500peak hp
5" primary = ~12,000-12,500peak hp

This is for a standard Honda B series engine. Different engines have different zones and there are millions of factors that affect this (altitude, humidity, barometric air pressure, etc).


A proper test of intake mani vs intake mani when you have a SET rpm that you are only willing to rev to, would be for manifolds with the same or similar primary lengths. AS soon as the primary length changes, that manifold is already designed and meant for a different engine/purpose. Don't go putting 10,500rpm manifolds on street engines only revving to 8500rpm... On the same hand don't go putting 8500rpm manifolds on 11,500rpm engines...



*Changing intake manifold primary lengths around and plenum sizing is very similar to changing expansion chambers on a 2 stroke engine. The intake manifold is pretty much the sole dictator of the powerband of the engine. There are other things that apply, but when it comes to greatly affecting the powerband (peak trq rpm) the intake manifold fits the ticket. You can "encourage" more powerband by messing with the cam gears or pulling/adding timing in the tune. Also an exhaust system that is restrictive will greatly kill the topend of your car, however these are just influences*

99black_em1

heres the link of the Kinsler vs Ported ITR dyno :
https://honda-tech.com/forums/showth...hlight=Kinsler

heres the link of the VictorX vs Ported ITR vs AIR dyno
https://honda-tech.com/forums/all-motor-naturally-aspirated-44/profunction-presents-bseries-intake-manifold-tests-version-2-0-l-endyn-edelbrock-itr-2836657/


Ok BMC, i see what you're saying. So in those tests, comparing the ITR to VictorX is not right, but the outcome of the Kinsler vs Ported ITR is there with gains of 30+ everywhere. On the engine used in those tests, can u make an Intake Manifold beat the Ported ITR everywhere just as the Kinslers did?

BMCRace

I honestly couldn't say, nor guarantee more power than the itb. I would say that I could most likely be right on the money with it. A properly designed manifold for an application no matter how it looks or who it was made by, will still be the right manifold for the application.

A plenumed manifold is typically alot more "peaky" in terms of power vs an itb. This is due to the tuned harmonic frequency to achieve the "supercharged" effect during a certain powerband. A itb doesn't rely on this and can't use it unless a plenum is placed over the vstacks to reverberate the harmonic frequency. My properly designed plenum manifold vs an open v stack itb setup would possibly net more power but only for a very small given rpm range (roughly 1500-2000rpm) of which the manifold was tuned for. Everywhere else it would most likely be making less power, possibly substantially less power.

What this equates to in the real world though, is an itb is an amazing tool for responsiveness and overall powerband. This would be perfect for a track car or anything that needs power in ALL rpm zones. However it might not be the best ticket for cars that run in a very limited rpm zone aka launch at 8krpm shift at 11k and the engine never drops below 8krpm. In this instance a much more "peakY" manifold would be a better ticket due to the harmonics tuning netting it more hp in that given rpm zone. You would sacrifice power down low yes, but who would care since you aren't ever in that low rpm except when putting around the pits?

99black_em1

ic ic. thats all i was curious about. seeing as how great the Kinsler did on the test, i just wondered if a well designed Manifold can do something similar.

If u were to design a manifold for that setup to shine in those tests in the link, what kind of plenum and length runners do u recommend? .. PM me if u can to talk more about design and pricing. thanks

BMCRace

That information sir would cost you the price of a manifold and your own time to measure it out and determine these things for yourself

I feel I have been quite generous with the amount of information given out already. Anything more would be giving the complete A-Z how to build these things. I mine as well go find another job at that point lol


Do yourself alot of research on the topic and then after about 1-2 years of trial and error, educated guesses, broken parts, etc. You will know what is needed for each application.

99black_em1

yes u been pretty generous. thats exactly what i was asking. I wanted to talk about pricing to order one from u because this isnt my thread and it goes against the HT rules.

p.s. not trying to get anything out of u. it would do me no good. jus wanted to make sure u can make what i need before ordering.