The OBX intake manifold. Some advice please.
Well, after reading so many threads retaining the infamous argument over the quality of obx products, I decided to take a chance and buy an intake manifold. I just sent my payment through for a "obx venom style intake manifold" for my b18b turbo civic. I am going dyno the car again soon, and out of curiosity, I am going to dyno my car with the oem manifold followed by this obx in an attempt to see what magnitude this manifold will have on performance. I just need some help/advice on how to get this manifold up and flowing.
I read before I buy, and the only intimidating quote from the description is "Custom drilling and tapping is required in order to utilize all factory sensor positions and auxiliaries." Wether or not I should take this lightly is up to me to find out. I can tap holes and wedge fittings into this manifold, but it still doesn't look like it will take all sensors. Maybe a picture will explain this better.
Here is what the stock manifold basically looks like.

Notice the oem sensor on the intake runner. Notice the coolant bypass fitting on the outer corner of the first runner. Also, there apears to be a bolt pattern and fluch surface adjacent to the throttle inlet for the stock sensor.
Now, here is the obx manifold.


Here is a the back of the manifold where there are holes ready to tap fittings into.

Now, where can I put the sensors that do not really have a place. Do I need to retain all of the sensors and does it matter is where all of the sensors are placed? Basically, can I rig this together by attaching all sensors to the back of the manifold, especially the sensor on the intake runner?
Please refrain from developing arguments of quality. Any advice is welcome. When I get recieve the manifold, I will post pictures of the intall, but till then, I would like some feedback that may help me. Thanks
I read before I buy, and the only intimidating quote from the description is "Custom drilling and tapping is required in order to utilize all factory sensor positions and auxiliaries." Wether or not I should take this lightly is up to me to find out. I can tap holes and wedge fittings into this manifold, but it still doesn't look like it will take all sensors. Maybe a picture will explain this better.
Here is what the stock manifold basically looks like.

Notice the oem sensor on the intake runner. Notice the coolant bypass fitting on the outer corner of the first runner. Also, there apears to be a bolt pattern and fluch surface adjacent to the throttle inlet for the stock sensor.
Now, here is the obx manifold.
Here is a the back of the manifold where there are holes ready to tap fittings into.

Now, where can I put the sensors that do not really have a place. Do I need to retain all of the sensors and does it matter is where all of the sensors are placed? Basically, can I rig this together by attaching all sensors to the back of the manifold, especially the sensor on the intake runner?
Please refrain from developing arguments of quality. Any advice is welcome. When I get recieve the manifold, I will post pictures of the intall, but till then, I would like some feedback that may help me. Thanks
I have heard that their SOHC manifolds can be a bitch to install because the flanges aren't flat, but thats what I've heard I have no proof. That sensor on the runner is the MAP sensor and will work any where it will fit as long as it sees a good crisp signal. Th brake booster will work on the back of the plenum but you need the proper fitting that will thread in. The largest hole should be used for the brake booster. I don't know how well this manifold will work because they probably put $5 into the R&D. It should make more power than the stock manifold but the flow between individual runners probably won't be as balanced as with the OEM manifold.
good luck!
good luck!
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000psi »</TD></TR><TR><TD CLASS="quote">That sensor on the runner is the MAP sensor and will work any where it will fit as long as it sees a good crisp signal.</TD></TR></TABLE>
Hmm, and I always thought that sensor was the IAT or intake air temperature sensor.
Hmm, and I always thought that sensor was the IAT or intake air temperature sensor.
Main things I see missing missing are: provisions for throttle cable, IACV, and IAT sensor. It also looks like you'll need to add some sort of nipple for the coolant passage on the passenger side of the flange. Assuming the bolt/stud pattern for the fuel rail is correct, the rest of the issues will be with tapping for all the vac sources you'd need, beyond the ones that are already tapped.
thats not the map on the runner, thats the IAT (intake Air Temp) the map is usually on the throotle body or the fire wall.Just thought i would clear that up
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<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by per4mance »</TD></TR><TR><TD CLASS="quote">thats not the map on the runner, thats the IAT (intake Air Temp) the map is usually on the throotle body or the fire wall.Just thought i would clear that up</TD></TR></TABLE>
I already did, but your answer gives more information.
I already did, but your answer gives more information.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dustin »</TD></TR><TR><TD CLASS="quote">What are you going to do with the IACV?</TD></TR></TABLE>
the iacv is a simple fix, basicly all you need is an adaptor plate for the stock iac. about 1/2inch thick, tapped for 2 1/4 npt fittings. these fittings get hooked into the charge pipe, and plenum respectivly. in the past i had a custom adaptor plate machined by a friend, the spacer went between the throttle body and where it bolts onto the plenum, which had holes machined into it, so that it resembled the factory "iac ports" than used the adaptor plate on the iac, to hook the vacum lines up to. this piece also bolted to the firewall. and the coolantlines get hooked up as normal.
also, you will need a throttle cable bracket welded onto the bottom of the manifold, or else, you can use a gsr throttle cable/bracket.
the iacv is a simple fix, basicly all you need is an adaptor plate for the stock iac. about 1/2inch thick, tapped for 2 1/4 npt fittings. these fittings get hooked into the charge pipe, and plenum respectivly. in the past i had a custom adaptor plate machined by a friend, the spacer went between the throttle body and where it bolts onto the plenum, which had holes machined into it, so that it resembled the factory "iac ports" than used the adaptor plate on the iac, to hook the vacum lines up to. this piece also bolted to the firewall. and the coolantlines get hooked up as normal.
also, you will need a throttle cable bracket welded onto the bottom of the manifold, or else, you can use a gsr throttle cable/bracket.
Yea. My main concern is the iacv. The iat will probably be simpl. I just need to make sure there are no leaks. I am not too worried about the throttle cable. I already have it rigged up in a way that it has no association with the intake plenum. Thanks for all the good advice. Keep it coming.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by per4mance »</TD></TR><TR><TD CLASS="quote">thats not the map on the runner, thats the IAT (intake Air Temp) the map is usually on the throotle body or the fire wall.Just thought i would clear that up</TD></TR></TABLE>
sorry, you're right....I 've never had a real Honda engine before.....only Y7's
thanks
im in the middle of installing the same piece of junk OBX manifold on my H22 prelude, really should have thrown it away but i decided to make it work. anyways heres problems ive had to deal with...
-same IACV problem, i just drilled and tapped the two holes on the IACV and i plan on simply hooking them up to vacuum.
-got the flange on the manifold surfaced ($40) at a local machine shop.
-rigged the throttle cable bracket to one of the studs that holds the fuel rail on.
-a few "T" connections for vacuum hookups
-oh yeah, had to say peace out to the fast idle valve on the throttle body because it wouldnt clear the rear engine mount with the new position of the manifold. i figured since aftermarket throttle bodies didnt hasve them they werent 100% manditory but i guess ill find out for sure.
-IAT sensor, planning on tapping the charge pipe for this as it will be the easiest fix and honda IAT's are so inaccurate anyway.
tried to start the car today with everything hooked up except for the IACV vacuum sources and of course the fast idle valve and my prelude started and just wouldnt idle, then died out pretty quickly. i have a feeling though that the IACV may fix this. ill post more after working on it tomorrow...
-same IACV problem, i just drilled and tapped the two holes on the IACV and i plan on simply hooking them up to vacuum.
-got the flange on the manifold surfaced ($40) at a local machine shop.
-rigged the throttle cable bracket to one of the studs that holds the fuel rail on.
-a few "T" connections for vacuum hookups
-oh yeah, had to say peace out to the fast idle valve on the throttle body because it wouldnt clear the rear engine mount with the new position of the manifold. i figured since aftermarket throttle bodies didnt hasve them they werent 100% manditory but i guess ill find out for sure.
-IAT sensor, planning on tapping the charge pipe for this as it will be the easiest fix and honda IAT's are so inaccurate anyway.
tried to start the car today with everything hooked up except for the IACV vacuum sources and of course the fast idle valve and my prelude started and just wouldnt idle, then died out pretty quickly. i have a feeling though that the IACV may fix this. ill post more after working on it tomorrow...
All I seem to hear is how bad obx sucks. I know that OBX is a step up from ssauto... I guess im just the guiena pig. I am buying this to see for myself if it was a wise investment.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lilbluehatch1 »</TD></TR><TR><TD CLASS="quote">friend had the obx manifold on his sohc for a month then the welds broke around the peleneum also it was boosted....</TD></TR></TABLE>
No ****? He blew the welds on his intake manifold....
sorry I couldn't help it.
No ****? He blew the welds on his intake manifold....
sorry I couldn't help it.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dc2legend »</TD></TR><TR><TD CLASS="quote">
No ****? He blew the welds on his intake manifold....
sorry I couldn't help it.</TD></TR></TABLE>
lol i hear ya heres a link to his blown motor https://honda-tech.com/zerothread?id=1312269
No ****? He blew the welds on his intake manifold....
sorry I couldn't help it.</TD></TR></TABLE>
lol i hear ya heres a link to his blown motor https://honda-tech.com/zerothread?id=1312269
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by trickeyMoSpo »</TD></TR><TR><TD CLASS="quote">***** that...
You get what you pay for... my buddy's leaked. Me= "told ya so" </TD></TR></TABLE>
yeah, the manifold quality does suck. yes the flange was not straight. $40 fixed that for me...and that was pretty expensive. your friends manifold leaked because he didnt get it surfaced before he installed it. anyway, the welds are not that bad, definately one of the better quality points of the IM.
as for buying a blox or skunk2, which im guessing are in the $400-$500+ range, i wont do it. the obx manifold sucks, but its nothing more than a copy of the venom design which isnt that bad. with my mods and the price of the manifold i spent less than $250. half the price. sure it has been a bitch to install but its a MUCH better manifold for boost than the s2 or blox mani. just more people jumping on a certain hater bandwagon.
You get what you pay for... my buddy's leaked. Me= "told ya so" </TD></TR></TABLE>
yeah, the manifold quality does suck. yes the flange was not straight. $40 fixed that for me...and that was pretty expensive. your friends manifold leaked because he didnt get it surfaced before he installed it. anyway, the welds are not that bad, definately one of the better quality points of the IM.
as for buying a blox or skunk2, which im guessing are in the $400-$500+ range, i wont do it. the obx manifold sucks, but its nothing more than a copy of the venom design which isnt that bad. with my mods and the price of the manifold i spent less than $250. half the price. sure it has been a bitch to install but its a MUCH better manifold for boost than the s2 or blox mani. just more people jumping on a certain hater bandwagon.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pheurton-skeurto »</TD></TR><TR><TD CLASS="quote">
as for buying a blox or skunk2, which im guessing are in the $400-$500+ range </TD></TR></TABLE>
Blox and Skunk are actually in the $180-250 range.
as for buying a blox or skunk2, which im guessing are in the $400-$500+ range </TD></TR></TABLE>
Blox and Skunk are actually in the $180-250 range.
Do I really have to get the manifold surfaced? It wont sit flush with the head or something? I find that hard to believe. The quality cant be that poor. I guess I will find out the hard way. Hopefully when I recieve it, i will clear up alot of confusion and rumors. Maybe the manifold isn't as poor quality as many people think, or maybe it is. There is apearantly a bias againt obx. People DO seem to jump the hate-band wagon just cause everyone else does, or they heard a story from a friend of a friend. Others complain about the manifold being poor quality due to the difficulty to install. As for the welds breaking, it is an intake manifold" it is not put through the same stress as a turbo manifold. I am very skepticle about the welds breaking. This manifold is basically a copy of the venom manifold. The desighn is rather simple. Four equal length runners on a box. I dont think it can be screwed up that bad. I guess I will have to wait and see.
Keep posting. Maybe someone out there has something GOOD to say about this manifold. Thanks for the feedback. I will post any updates in this thread.
Keep posting. Maybe someone out there has something GOOD to say about this manifold. Thanks for the feedback. I will post any updates in this thread.



