Best OTR?

[DR-vyss-108]

Hi,

I am desperate to know which OTR has made the best gains in all N/A application?
Anyone with back to back results whether it be dyno or strip/track?

Did a search and nothing came up for this

[Mitchg]

DUS OTR. Google duspeed.

Old man is running on in his monaro, consistent 11.5@117mph and is awesome. About $650 installed and look awesome!

[macca_779]

Desperate is a bit extreme.

I gather your looking for a VY going by your name.

It's a very personal choice as there really isn't alot in them. I use a DUS one and they work fine, but so do a few others. You won't get a straight answer though. There are ones out there that I think are shit but others like so good luck getting a clear answer.


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[VYSHSV8]

Desperate is a bit extreme.

I gather your looking for a VY going by your name.

It's a very personal choice as there really isn't alot in them. I use a DUS one and they work fine, but so do a few others. You won't get a straight answer though. There are ones out there that I think are shit but others like so good luck getting a clear answer.


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Yeh yeh yeh I use the same :)

but i know which one i wont use hehe

[DR-vyss-108]

I thought that would be the case, but so far the thread is looking a little one sided

[OMR346]

I have a Ziggy. They are alloy and look great polished up. Around $500, and takes about half hour to install.

DUS also seem to be rather popular. I prefer the alloy one though.

And before anyone starts the whole alloy and heat soak thing, it has no effect when the car is moving. Many have done tests and proven it to be a crock of shit lol

[DR-vyss-108]

I have had a plastic one and a Ziggy, but have sold both, it's for a race car, don't know what to try next

[VYSHSV8]

if its for a race car go a custom alloy :)

END OF STORY

aka get one made you dont need a filter

[whitels1ss]

These ones are very good.:hide:

http://www.youtube.com/watch?v=isxnguk1qYU

[DR-vyss-108]

Who would make a custom one?
Race car as in Tarmac rally car

[VendeTTR]

drvyss108, you should try find yourself an old G&D OTR that picks up air from the grill :)
http://i33.photobucket.com/albums/d62/sexbomb1307/SANY1126.jpg

[Mitchg]

^ Thats exactly what a DUS does, cept its prettier

http://i32.photobucket.com/albums/d18/US063/0calais0/IMG_2008.jpg

The air scoop sits down collecting fresh air from behind the grille

[VZ_V8]

^ Thats exactly what a DUS does, cept its prettier

The air scoop sits down collecting fresh air from behind the grille

Thought I was looking at my own car for a second!!

http://i117.photobucket.com/albums/o64/tim6489/VZ%20SS%20Thunder%20Finished/Engine1.jpg

However I have since changed to a VCM Performance Alloy OTR and have not looked back since...

http://i117.photobucket.com/albums/o64/tim6489/IMG_2475-1.jpg

[BEARWOOD]

This question is as popular as "what is the best exhaust". There will be no definative answer just opinions, and opinions will be based on what people own and what their mates cousins mechanic told them. If its a serious race car get one fabricated. Theres not enough difference in any of the good ones to lose sleep over and it definately wont cause you to lose a race.

[macca_779]

These ones are very good.:hide:

http://www.youtube.com/watch?v=isxnguk1qYU

I went from one of them to a DUS. No difference in measured MAP. Filter is why that one sucked in


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[A^K^T]

I went from one of them to a DUS. No difference in measured MAP. Filter is why that one sucked in


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I went from a popular otr back to my PT OTR , havn't seen the PT OTR do that.

[macca_779]

I went from a popular otr back to my PT OTR , havn't seen the PT OTR do that.

A PT will do that with a shit filter


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[Xjas]

Theres not enough difference in any of the good ones to lose sleep over and it definately wont cause you to lose a race.

Bearwood is right, pick one that is known to be among the good ones and move on, if its for a tarmac car your time would be better spent chasing performance in other areas, the absolute best to average OTRs would only vary by a handful of kws and that would only be at redline anyway, thats why I doubt you'll find a conclusive back to back test, its too hard to verify results that fine when you cant 100% control the measuring conditions.

[Tryhard]

Stick to either a vcm or a duspeed and you won't look back. Like bearwood said there's not enough difference in any of the good ones to lose sleep over. The duspeed ones do look sexy though imo.

[VYSHSV8]

I went from a popular otr back to my PT OTR , havn't seen the PT OTR do that.

Haha yeh I know why you changed otr's ;)


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[lukemcg]

I have a RAMJET on my VU and it does the job, I wouldnt imagine there would be much between the better ones such as ramjet, VCM or the DUS OTR intakes, as they all seem to extend down behind the grill.

[macca_779]

I have a RAMJET on my VU and it does the job, I wouldnt imagine there would be much between the better ones such as ramjet, VCM or the DUS OTR intakes, as they all seem to extend down behind the grill.

What makes you say the Ramjet is one of the better ones?


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[VYSHSV8]

What makes you say the Ramjet is one of the better ones?


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Mmm can't wait for the response
Now where's my Jacks and popcorn hehe oh shit i am still driving ;)


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[OMR346]

Mmm can't wait for the response
Now where's my Jacks and popcorn hehe oh shit i am still driving ;)


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I'll have one for ya since I'm not driving :beer: :popcorn:

This ought to be good lol

[lukemcg]

What makes you say the Ramjet is one of the better ones?


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Nothing specifically, just the impression I was under, to be honest it wouldn't have been my first choice but was on the car when I bought it, and cant really justify spending $600+ to change it to anything else, for little or no gain.

Not to start a war or insult anyone (especially as there are alot of people on here with alot more automotive experience than me, yourself included macca), but what makes you say that the ramjet is NOT one of the better ones? From where Im standing its a piece of plastic with a K&N Filter stuck in the end of it. It gets plenty of air through the grill, which runs through to the throttle body through a big hose. I cant see how the others would be any different, aside from a glossy paint job or aluminium finish.

I cant see my car (or alot of other cars on here for that matter) ever being at a level where the small differences in OTR intake types start becoming a problem.

Feel free to correct me, like I said Im not trying to start an argument.

[A PSYCHO]

Ive only used a Ziggy and if i had my time again i would probably look at the DUSpeed or VCM. Pulled the filter off my Ziggys to clean the filter and found dirty water stains inside the OTR 2/3s of the way up the OTR getting quite close to the TB. Im assuming it had happened during heavy rain. Also the sensor plug/hole on the side was always loose and easily movable. Did it ever actually fail or cause problems? Not really, so it wasnt a waste of money or particularly bad product. But as said, would look to the more popular options next time around.

[feistl]

I cant see my car (or alot of other cars on here for that matter) ever being at a level where the small differences in OTR intake types start becoming a problem

I tend to agree, for most engine combinations there are far more limiting factors than the OTR. Once you get into heavily worked/high powered engines it might start to make a bit more difference but on a bolt on setup the gains will be minimal. That said, if your buying one for the first time, go with one of the better brands... But if you already have one i would be spending the money elsewhere. EG Diff gears are a better "bang for buck" upgrade compared to "upgrading" an OTR (EG replacing a basic one with a more expensive one).

[V8_Power]

if its for a race car go a custom alloy :)

END OF STORY

aka get one made you dont need a filter

Assuming he is circuit racing, ever gone off into the dirt on a race track... Air cleaner 100% must. If it's for the drags, I'd agree with you there. Not required.

[Phillshz]

Thought I was looking at my own car for a second!!

http://i117.photobucket.com/albums/o64/tim6489/VZ%20SS%20Thunder%20Finished/Engine1.jpg

However I have since changed to a VCM Performance Alloy OTR and have not looked back since...

http://i117.photobucket.com/albums/o64/tim6489/IMG_2475-1.jpg

What was your reason for swapping from a Dus to a VCM? Was there any noticable benefit from the change eg: lower or more consistant IAT`s, better intake noise, clearance, better suited to a L76/L98 etc. Just curious.

Cheers Phill

[DR-vyss-108]

Can someone explain why the filter surface area is so small? And why the 'eBay' ones with the bigger filters aren't better off?
Just interested to know the reason behind it as obviously they work better with the smaller filter area

[VZ_V8]

What was your reason for swapping from a Dus to a VCM? Was there any noticable benefit from the change eg: lower or more consistant IAT`s, better intake noise, clearance, better suited to a L76/L98 etc. Just curious.

Cheers Phill

There were 5 main reasons why I made the change.

1) The intake didnt align properly with the neck of the throttle body and because of the way it attached and its shape it couldn't be moved to align it properly without modifying it a fair bit.

2) I had some pretty heavy rubbing spots. One big one on the drivers side near the rad cap, 1 very deep one right in the middle, and then some lighter rubbing along the length of the radius above the filter. There was also some cracking in the paint in
spots due to the fibreglass flexing. It was fully primed and painted in 2k.

3) The filter didn't seem to filter properly, when changing the filter out there was always a fine grit on the inside of the intake. However I reduced most of this by smearing a thick bead of grease the whole way around the filter channel to seal it up.
This made it a bit of a messy process when taking the filter out for cleaning but at least it sealed it up better.

4) The IAT position I didn't like and it ended up causing my IAT sensor to fail because it corroded due to exposure. Not long before I sold the intake I re-drilled this in near the neck of the intake so the new sensor didnt fail as well.

5) I got the VCM for about half price and it has none of the issues I have mentioned above. Yes it gets heat soak whilst sitting at lights and IATs go up a little bit, but give it 30 seconds of driving again and the temps are back down.


Power wise there was no difference, but that was of no consideration to me when I made the change. Don't get me wrong the DUS unit looks fantastic and if it didn't have the issues I mentioned I would still be using it. However they were enough to make me change and I am happier with my current setup.

Tim

[whitels1ss]

Can someone explain why the filter surface area is so small? And why the 'eBay' ones with the bigger filters aren't better off?
Just interested to know the reason behind it as obviously they work better with the smaller filter area
The surface area of the filter is much larger than the surface area of the front face of the throttle body anyway...(I am guessing 5 times bigger???)
and there is only a certain sized "pillar box" like gap for the air to get over the radiator under the bottom of the bonnet,
so as long as the filter is kept clean they work very well.

[DR-vyss-108]

Makes sense, thanks for that

[dyno junkie]

I'm yet to find an OTRCAI that doesn't make more power and go faster down the track with the filter removed.

[Phillshz]

There were 5 main reasons why I made the change.

1) The intake didnt align properly with the neck of the throttle body and because of the way it attached and its shape it couldn't be moved to align it properly without modifying it a fair bit.

2) I had some pretty heavy rubbing spots. One big one on the drivers side near the rad cap, 1 very deep one right in the middle, and then some lighter rubbing along the length of the radius above the filter. There was also some cracking in the paint in
spots due to the fibreglass flexing. It was fully primed and painted in 2k.

3) The filter didn't seem to filter properly, when changing the filter out there was always a fine grit on the inside of the intake. However I reduced most of this by smearing a thick bead of grease the whole way around the filter channel to seal it up.
This made it a bit of a messy process when taking the filter out for cleaning but at least it sealed it up better.

4) The IAT position I didn't like and it ended up causing my IAT sensor to fail because it corroded due to exposure. Not long before I sold the intake I re-drilled this in near the neck of the intake so the new sensor didnt fail as well.

5) I got the VCM for about half price and it has none of the issues I have mentioned above. Yes it gets heat soak whilst sitting at lights and IATs go up a little bit, but give it 30 seconds of driving again and the temps are back down.


Power wise there was no difference, but that was of no consideration to me when I made the change. Don't get me wrong the DUS unit looks fantastic and if it didn't have the issues I mentioned I would still be using it. However they were enough to make me change and I am happier with my current setup.

Tim

Thanks Tim, That`s a bummer about your issues with the DUS. They are a nice looking unit and are highly recommended and regarded by most on here.
Do you think your track day use (being that it`s obviously hard on cars) caused most of the little issues?

The fine grit of dust, post filter is a worry. I don`t recall any others mentioning it before?? Maybe you could contact Dus with your issues/feedback to help with some QC or design tweaks.

With the IAT moved to the neck area on the Dus how were the heatsoak and IAT`s compared to the VCM? I`m sure the DUS would heat up at idle just as much as a VCM??

Nice buy with the VCM $$!

Cheers Phill

[calais190]

I had a VCM, and went to a DUSPEED V3 on my VE. A couple basic reasons. My VCM unit had lots of issues sealing properly (VCM fixed it eventually, with extra foam on their bracket - great customer service they have though). The bracket "fix" is hardly a fix, more just a bandaid IMO. Cleaning the filter was a process and a half. Taking the OTR housing out of the engine bay every few thousand Kms to clean the filter is just plain annoying. The DUSPEED is very easy to clean, and seals up without an issue. Well worth the swap as I don't dread pulling the filter out to clean. I like the look of the DUSPEED better too, but it gets dirty quickly. Power difference is zero. Noticed absolutely no change.

My experience relates to VE only.

[feistl]

Taking the OTR housing out of the engine bay every few thousand Kms to clean the filter is just plain annoying.

And complete overkill.... Why are you cleaning the filter every few thousand kms? There have been tests done where ultra dirty filters have been dyno'd and compared to brand new filters and shown absolutely no difference. Id say a filter only needs cleaning every 3-4 years.. any more than that is pointless. (If you drive 300km a day on dirt roads you might do it once a year).

[SimonNQ]

I didn't clean mine for about 6 months after the initial install, around 15,000 k's i noticed quite a difference in the responsiveness of the engine after the clean. I have the VCM.

[VXSS346]

And complete overkill.... Why are you cleaning the filter every few thousand kms? There have been tests done where ultra dirty filters have been dyno'd and compared to brand new filters and shown absolutely no difference. Id say a filter only needs cleaning every 3-4 years.. any more than that is pointless. (If you drive 300km a day on dirt roads you might do it once a year).

Dunno about tests done but mine gets clogged up with dirt within a few thousand kms, so theres no way I can leave mine that long. Just normal suburban driving too.

[5.7heaven]

+1 for the alloy VCM OTR. Had one on my VX wagon and now one on my Monaro and both work perfectly fine and give an awesome induction growl

[macca_779]

And complete overkill.... Why are you cleaning the filter every few thousand kms? There have been tests done where ultra dirty filters have been dyno'd and compared to brand new filters and shown absolutely no difference. Id say a filter only needs cleaning every 3-4 years.. any more than that is pointless. (If you drive 300km a day on dirt roads you might do it once a year).

Really depends where you drive. I've been down dirt roads following others at a distance and it gets filthy quick smart


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[feistl]

Dunno about tests done but mine gets clogged up with dirt within a few thousand kms, so theres no way I can leave mine that long. Just normal suburban driving too.

I have no doubt it gets dirty, but my point was that even a filthy filter flows so much air its not going to impact performance. Eg when clean the filter is probably capable of 200% more flow than required by the engine, so even if that drops to 150% when dirty its still not going to be an issue.

K&N recommend cleaning every 50,000 miles, and i think the only reason they recommend this is to put new oil in as the oil helps capture dust etc. So yeah, even if its dirty i dont think you need to clean it that often.

[macca_779]

I have no doubt it gets dirty, but my point was that even a filthy filter flows so much air its not going to impact performance. Eg when clean the filter is probably capable of 200% more flow than required by the engine, so even if that drops to 150% when dirty its still not going to be an issue.

K&N recommend cleaning every 50,000 miles, and i think the only reason they recommend this is to put new oil in as the oil helps capture dust etc. So yeah, even if its dirty i dont think you need to clean it that often.

It's a fair point. I agree that overall people probably do over service things like this.


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[VZ_V8]

Thanks Tim, That`s a bummer about your issues with the DUS. They are a nice looking unit and are highly recommended and regarded by most on here.
Do you think your track day use (being that it`s obviously hard on cars) caused most of the little issues?

The fine grit of dust, post filter is a worry. I don`t recall any others mentioning it before?? Maybe you could contact Dus with your issues/feedback to help with some QC or design tweaks.

With the IAT moved to the neck area on the Dus how were the heatsoak and IAT`s compared to the VCM? I`m sure the DUS would heat up at idle just as much as a VCM??

Nice buy with the VCM $$!

Cheers Phill

Hi Phil,

I can't see the track days making any difference, the setup can't move as it is all clipped in along the rad support, I had the bonnet adjusted up to try and get more clearance and had also knocked down the top cores of the radiator and tweaked the condensor back to get it to sit as low as possible. Plus the alignment issues were there from the start and the rubbing had started before the first track day I took the ute on. I know track days are hard on the car but the intake isn't a moving part like the suspension or brakes etc. so really it should not be affected.

To be honest I can't remember how the IATs were affected by moving the sensor. It was quite sometime ago now that I changed the intake to the VCM one, I would imagine it would heat up just the same, but I suppose the Ally would retain the heat a little more than the fibreglass? Either way once you're moving it doesn't have much effect anyway.

[VXSS346]

I have no doubt it gets dirty, but my point was that even a filthy filter flows so much air its not going to impact performance. Eg when clean the filter is probably capable of 200% more flow than required by the engine, so even if that drops to 150% when dirty its still not going to be an issue.

K&N recommend cleaning every 50,000 miles, and i think the only reason they recommend this is to put new oil in as the oil helps capture dust etc. So yeah, even if its dirty i dont think you need to clean it that often.

Point taken :) and that is probably the case as I cant really tell any difference in performance once I clean it, but the way I see it, why wait until its clogged up to the point of less performance? Its preventative maintenance after all. :yup:

Even after a few thousand kms when I do clean it, it looks very blocked, maybe I'm over servicing it, maybe I'm not, but I'm happy doing it. :)

As for which OTR is best, ..........I'd say the one that makes you happy. :idea:

[OMR346]

All I do with my filter is give it a tap on the ground to knock the bugs, etc, out when ever I take it out. Normally I do a fair few trips to Willowbank and it always comes out then. But it hasn't been out since February so its due for a clean.

[5.7heaven]

i've heard removing the filter from the OTR while doing 1/4mile runs is ok because no-one is in front to kick up rocks etc??
havent done it personally for obvious reasons, but can anyone vouch for the power gains??

[OMR346]

Me and a mate were at Willowbank last year. He did some runs in his old VT SS with the filter in then removed it. The result was .2 second faster over the 1/4 mile with out the filter. I have always taken mine out but will test it myself some time. I just haven't done it yet.

[5.7heaven]

Interesting.......

[Woodchukka]

I had a VL turbo with a K&N pod filter and was curious about how often to clean in and fitted an air filter restriction indicator and it was over 10,000km before it even moved one little bit. I left the indicator on there and cleaned the filter when is showed any restriction and not a day before.

[Phillshz]

Me and a mate were at Willowbank last year. He did some runs in his old VT SS with the filter in then removed it. The result was .2 second faster over the 1/4 mile with out the filter. I have always taken mine out but will test it myself some time. I just haven't done it yet.

Ahem... may i point your attention here, http://autospeed.com/cms/title_Dont-Bother-Changing-the-Factory-Filter/A_111486/article.html
Running without a filter is asking for trouble, track or not.
Car intake systems seems to be a pet hobby of Julian, you just need to see how many he test`s :weirdo: so i`m sure he knows a thing or two.

Tim, by being hard on the car i meant on engine/trans mounts and under bonnet heat. If the drivetrain is regulary subjected to high stresses (flexing way more than a street only car) it may have in turn been flexing the Dus? Extra track day use heat might have contributed too?. Most people stay on the street or do very few 1/4 runs so the issues might not show up under that usage.

Cheers Phill

[OMR346]

Ahem... may i point your attention here, http://autospeed.com/cms/title_Dont-Bother-Changing-the-Factory-Filter/A_111486/article.html
Running without a filter is asking for trouble, track or not.
Car intake systems seems to be a pet hobby of Julian, you just need to see how many he test`s :weirdo: so i`m sure he knows a thing or two.

Interesting read. Although he mentions factory air boxes. We are talking about an aftermarket OTR set up.

[VZ_V8]

Tim, by being hard on the car i meant on engine/trans mounts and under bonnet heat. If the drivetrain is regulary subjected to high stresses (flexing way more than a street only car) it may have in turn been flexing the Dus? Extra track day use heat might have contributed too?. Most people stay on the street or do very few 1/4 runs so the issues might not show up under that usage.

Cheers Phill

Possibly, however I know of another unit which was sent back because of alignment issues and a different one again which has rub marks the same as mine did as well as cracking and it is on a car which gets used very little only on the street.

[Phillshz]

True! But a filter is still a filter, doesn`t matter whether it`s tucked away in a airbox or sitting out in front of a OTR air still pass`s through it.
The way the "engine" see`s it, is that the filter doesn`t "exist" as it is not a restriction.
OTR`s build up air pressure in front of the filter from approx 100km/h (at WOT). This slight "boost" is then forced through the filter & OTR body into the manifold etc.

Cheers Phill

[kevin101]

best otr is a tissue box, cut one whole side out cut a hole on the opposite side for your intake pipe, built in filter.. You will then have some tissues on hand whilst having a 4 paged debate on whats the best otr. Just get one that you or the bloke next door likes and use it.

[BOSSVY]

so if otrcais are so bad and you get no increase in power as a few have stated why do people buy them ??? they are well marketed ?? theyre in all the mags , few ppl say there good others say not ......

this is very interesting to me as im on the hunt for a vcm and soon to be doing my maffless tune after otrcai but if im not going to gain anything at all from them i might just go mafless tune instead ????

vyss03

oh and how can i change my signature lol

[lmoengnr]

OTR`s build up air pressure in front of the filter from approx 100km/h (at WOT). This slight "boost" is then forced through the filter & OTR body into the manifold etc.


I'd like to know how you came up with that piece of information.

[macca_779]

I'd like to know how you came up with that piece of information.

Stick your hand out the window at 100km/h.

While the benefit of ram air is there. Its miniscule at legal or realistic speeds.

[lmoengnr]

Stick your hand out the window at 100km/h.


Thats actually drag you're feeling........

You wont get any ram recovery till you're doing approx 180 knots, and only then if the airflow is entering a divergent duct.

All the otrcai assys. I've looked at are all convergent type ducts.

[steve_t]

It's probably not so much a boost than a reduction in what would otherwise be a stronger vacuum.

[Phillshz]

Stick your hand out the window at 100km/h.

While the benefit of ram air is there. Its miniscule at legal or realistic speeds.

lmoengnr, I find this thread highly informative. All your answers should be in there. http://www.ls1.com.au/forum/showthread.php?153422-Results-of-Pressure-testing-VE-Intake-systems&highlight=ve+pressure+testing

Then read this fully http://autospeed.com.au/cms/title_Pressure-Gauges-and-Making-Power/A_112718/article.html
The part of most interest is the using positive and negative gauge sections.


Well i guess technically it is drag that your feeling with your hand out the window, since you are moving at speed and the air is relatively stationary (you turn that drag into a positive pressure by trapping/forcing it against something eg: a OTR filter or T/B). It is a pressure if your stationary and the wind is blowing a gale and blowing you over, think High and Low weather pressure systems etc etc

Cheers Phill

[VYSHSV8]

Assuming he is circuit racing, ever gone off into the dirt on a race track... Air cleaner 100% must. If it's for the drags, I'd agree with you there. Not required.

Yep been of track before and seeing as the engine is in the front didn't bother me :) just kept the boot into to get back on :)

[bermudablue]

pretty much all the same these days,
But pull the filter out before you run

[markone2]

i've heard removing the filter from the OTR while doing 1/4mile runs is ok because no-one is in front to kick up rocks etc??
havent done it personally for obvious reasons, but can anyone vouch for the power gains??

up to 3/10ths and 3mph..in some cases more...100% given on NA cars..not opinion...proven.

[whitels1ss]

up to 3/10ths and 3mph..in some cases more...100% given on NA cars..not opinion...proven.
Thats amazing:cheers:

[dyno junkie]

Not so amazing, most OTRCAI have a smaller filter than the stock air box.

[zorro]

Stick your hand out the window at 100km/h.

While the benefit of ram air is there. Its miniscule at legal or realistic speeds.

It would only 'ram' air if the air speed was greater than the rate of air the engine was taking through the t/b. if that was the case then effectively would be forced induction.

The otr unfiltered is really only a guide to the t/b with effectiveness governed by how much ft3 can pass through the opening, if it doesn't exceed how much ft3 the engine takes at WOT then it is choking the engine.