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View Full Version : Pbm Cobra downpipe torque loss


zbarsuglia
05-31-2015, 04:21 PM
I am contemplating buying a Pbm cobra downpipe for my sr but am second guessing myself because I have heard that you lose torque. Does anyone have any experience with this?

dizzariot
05-31-2015, 05:18 PM
I am contemplating buying a Pbm cobra downpipe for my sr but am second guessing myself because I have heard that you lose torque. Does anyone have any experience with this?

I just put one on my SR and I haven't notice a difference? What's the 'science' behind this theory...?

MADE
05-31-2015, 05:34 PM
My friend used a Cobra styled pipe it didn't last long, and the tuner didn't called it. That was the first and only DP that I seen crack. Not sure about the torque though. Im sure more people have had success but the one piece doesn't suit me. Also is your not extremely low what is the up side?

JBB
05-31-2015, 05:54 PM
Also is your not extremely low what is the up side?

Buying one pipe instead of two?

brndck
05-31-2015, 07:30 PM
ive been running the same "cobra" downpipe for years with no downside. better clearance underneath, no more blown out downpipe gaskets, i've encountered zero downsides to it.

who told you you "lose torque" using this type? did they have before/after dyno graphs to show proof of this claim?

dizzariot
05-31-2015, 08:24 PM
who told you you "lose torque" using this type? did they have before/after dyno graphs to show proof of this claim?

That's what I'm saying...I just replaced all my fucking gaskets and the thought of avoiding that altogether sold me on the Cobra Flex.

MADE
05-31-2015, 08:37 PM
ive been running the same "cobra" downpipe for years with no downside. better clearance underneath, no more blown out downpipe gaskets, i've encountered zero downsides to it.


Are you using solid mounts?

zbarsuglia
05-31-2015, 09:26 PM
I just put one on my SR and I haven't notice a difference? What's the 'science' behind this theory...?

No idea. At this point it's all hear say. I have already bought the newest version of the tomei elbow and a trust downpipe but would much rather have the cobra for gasket/clearance.

ive been running the same "cobra" downpipe for years with no downside. better clearance underneath, no more blown out downpipe gaskets, i've encountered zero downsides to it.

who told you you "lose torque" using this type? did they have before/after dyno graphs to show proof of this claim?

A friend on Instagram said he noticed a slight loss. But I questioned myself an couldn't find reasoning why it would do that.

All in all thanks for your input. All of you. If mods want to shut this down they can

nujabe
05-31-2015, 10:07 PM
it was meh who said that. i went from a tomei blitz dp set up to cobra and noticed the difference. i have a decent engine set up i've been running for years now, but i've been using cobra for a few months now and to be honest the clearance alone is worth what ever numbers its giving me also not having to tighten my outlet bolts every few months is really nice.

FaLKoN240
05-31-2015, 11:07 PM
My friend used a Cobra styled pipe it didn't last long, and the tuner didn't called it. That was the first and only DP that I seen crack. Not sure about the torque though. Im sure more people have had success but the one piece doesn't suit me. Also is your not extremely low what is the up side?

Cobra "styled"

So he was using a PBM DP or not?

The upside to using this pipe is the flex section is in the vertical section instead of the horizontal section.

I've seen dozens of flex sections on other DPs shredded because of low ride height.

brndck
05-31-2015, 11:18 PM
Are you using solid mounts?
i'm on nismo mounts, no flex section anywhere in my exhaust. i don't crack manifolds, blow out gaskets, or have any other issues with my setup.
mine is this style

http://i268.photobucket.com/albums/jj10/gazelle_88/243_zps58bcc438.jpg

it was meh who said that. i went from a tomei blitz dp set up to cobra and noticed the difference. i have a decent engine set up i've been running for years now, but i've been using cobra for a few months now and to be honest the clearance alone is worth what ever numbers its giving me also not having to tighten my outlet bolts every few months is really nice.

i'd be curious to see a dyno graph comparison to see what the numbers say. maybe you do lose a few when switching to a cobra style.

nujabe
06-01-2015, 11:16 AM
me to i had the car dyno'd with the tomei blitz set made 320 whp around 312 wtq cobra pipping seems a little smaller then the blitz.

corby_baby
06-01-2015, 01:01 PM
mine is this style

http://i268.photobucket.com/albums/jj10/gazelle_88/243_zps58bcc438.jpg



Circuit Sports ;)

brndck
06-01-2015, 07:35 PM
Circuit Sports ;)

dmax akshully

ZX88
06-01-2015, 07:53 PM
i like my cobra. not sure if they clearance was any better than the solid down pipe i had on there before, but at least I wont have to replace that gasket as often.

hellaslows13
06-01-2015, 11:37 PM
For you peeps running tomei expreme manifold on your sr, what dp are you using with that? Sorry, didn't mean to divert the subject. Figured i'd ask since we were on the subject of downpipes. I wanted to run the pbm cobra pipe but looks like the only way to run it with the tomei manifold would be to modify it..

corby_baby
06-02-2015, 08:24 AM
compared to other similar setups and dyno's, i might have lost a little torque but not sure if that is due to the cams or not. Regardless, not scraping on everything far outweighs the slight amount of torque lost if any.

380whp/340 wtq - KA-t - gt2871r @ 15psi - pump gas and supporting mods.

http://i19.photobucket.com/albums/b187/corbeybaby/2F6C0303-7B94-47C7-A5DF-EF7EA5C5A57E_zpsvezpqx14.jpg (http://s19.photobucket.com/user/corbeybaby/media/2F6C0303-7B94-47C7-A5DF-EF7EA5C5A57E_zpsvezpqx14.jpg.html)

Trinidrift3
06-02-2015, 05:46 PM
You won't feel a torque loss

And to people with gasket/cracking manifold issues: tack weld the nuts to prevent them from backing out and blowing the gaskets. and stick with the oem cast, manifold unless you are going larger than t2, and you'll never have cracking issues

MADE
06-02-2015, 07:07 PM
Cobra "styled"

So he was using a PBM DP or not?

The upside to using this pipe is the flex section is in the vertical section instead of the horizontal section.

I've seen dozens of flex sections on other DPs shredded because of low ride height.

Unknown looked like a D-Dmax it had no flex, and the tuner didn't like the bends in the design.

I said styled as I didnt want to imply I was bashing PBM.

CamryOnBronze
06-03-2015, 06:49 AM
Are you using solid mounts?

I ran a Parts Shop Max Cobra downpipe with Cusco engine mounts for three years and about 19k miles or so. I never had an issue with cracking or blown out gaskets.

For you peeps running tomei expreme manifold on your sr, what dp are you using with that? Sorry, didn't mean to divert the subject. Figured i'd ask since we were on the subject of downpipes. I wanted to run the pbm cobra pipe but looks like the only way to run it with the tomei manifold would be to modify it..

I think I am the reason that the disclaimer about the Tomei manifold is on their website. I had to heat up the turbo elbow and tap it with a hammer a few times to get it to clear my transmission so I sent them an email to let them know. I never heard if anyone else had the same issue though.

S14DB
06-03-2015, 02:32 PM
I would like to know what the OP was using before the PBM Cobra. Stock cast iron outlet?
I assume this is a seat dyno comparison. I cant figure how you would get a loss post turbine unless the pipe was so insanely big you were getting stagnation. Which 3" is not big enough to cause.
Unless a dyno sheet is shown, I chalk it up to smoothing out the power band. Loss in surge feels like a loss in power. When you actually gained power.

Unknown looked like a D-Dmax it had no flex, and the tuner didn't like the bends in the design.

I said styled as I didnt want to imply I was bashing PBM.

That was a crack in the pipe not a bad weld from manufacture. I see two issues:
1) The metal is too thin or low grade.
2) No flex joint and probably no transmission brace ether. The whole exhaust system is swinging back and forth from the turbo mount. Twisting the up pipe portion of the cobra.

Ultimately you can't knock on PBM or the "style" when you are using a clone.

hellaslows13
06-04-2015, 03:03 AM
I ran a Parts Shop Max Cobra downpipe with Cusco engine mounts for three years and about 19k miles or so. I never had an issue with cracking or blown out gaskets.



I think I am the reason that the disclaimer about the Tomei manifold is on their website. I had to heat up the turbo elbow and tap it with a hammer a few times to get it to clear my transmission so I sent them an email to let them know. I never heard if anyone else had the same issue though.


Thanks for chiming in. So were you able to make the pbm cobra work with the tomei manifold with just a bit of brute force? I want to run this setup on my s14 with s14 sr...

CamryOnBronze
06-04-2015, 11:27 AM
Thanks for chiming in. So were you able to make the pbm cobra work with the tomei manifold with just a bit of brute force? I want to run this setup on my s14 with s14 sr...

Yep, it wasn't bad at all. A portion of the elbow was contacting the transmission. Heated it up and gave it a few hits with a ball peen hammer and that gave me the clearance I needed. I am sure it all depends on your engine and transmission mounts to some extent. This was with Cusco solid engine mounts and a NISMO transmission mount. It really wasn't too bad at all though!

offthewall
06-04-2015, 02:49 PM
I cant figure how you would get a loss post turbine unless the pipe was so insanely big you were getting stagnation. Which 3" is not big enough to cause.
Unless a dyno sheet is shown, I chalk it up to smoothing out the power band. Loss in surge feels like a loss in power. When you actually gained power.


This. The best exhaust for a turbo is the shortest/largest bore exhaust. It's impossible to get a torque loss from making the exhaust larger on a turbo car unless you really screw the flow path up.

hellaslows13
06-04-2015, 04:06 PM
Yep, it wasn't bad at all. A portion of the elbow was contacting the transmission. Heated it up and gave it a few hits with a ball peen hammer and that gave me the clearance I needed. I am sure it all depends on your engine and transmission mounts to some extent. This was with Cusco solid engine mounts and a NISMO transmission mount. It really wasn't too bad at all though!

Thanks man, might bite the bullet and try the pbm cobra pipe.

P.S. your blog awesome, inspires me to get mine going... :2f2f:

MADE
06-05-2015, 06:28 PM
That was a crack in the pipe not a bad weld from manufacture. I see two issues:
1) The metal is too thin or low grade.
2) No flex joint and probably no transmission brace ether. The whole exhaust system is swinging back and forth from the turbo mount. Twisting the up pipe portion of the cobra.

Ultimately you can't knock on PBM or the "style" when you are using a clone.

Metal being thin maybe?
It did have a transmission brace, but no flex, the car had ever solid mount and bushing made and was trashed on the road and track. Bolts, would come loose like it was cool.
In Japan not may clones around, Im pretty sure it was a legit D-max produced.

Random failure, so I won't knock it, and as I mentioned I'm not implying PBM is a bad product.

CamryOnBronze
06-08-2015, 07:59 AM
Thanks man, might bite the bullet and try the pbm cobra pipe.

P.S. your blog awesome, inspires me to get mine going... :2f2f:

Thanks man! Yeah give it a shot for sure, shouldn't be too bad!

jerry_beans
06-08-2015, 11:43 AM
For you peeps running tomei expreme manifold on your sr, what dp are you using with that? Sorry, didn't mean to divert the subject. Figured i'd ask since we were on the subject of downpipes. I wanted to run the pbm cobra pipe but looks like the only way to run it with the tomei manifold would be to modify it..

Nope, no modification needed I run Tomei expreme with stock t28 and the PartsShopMax cobra. The only thing is that the O2 sensor is close to the bell housing. I'm actually running CamryOnBronzes old Tomei manifold!

2slow2go
04-02-2018, 04:13 PM
Reviving an old thread. i have a pbm pipe for my sr20. I remember the pbm folks told me to only use a bottom mount exhaust manifold for alignment with the pbm cobra pipe.

Does anyone know any aftermarket brands of manifold that they've tried that fits perfectly with the pbm pipe? I've heard the tomei bottom mount doesnt line up well.. Is stock the only option?

FaLKoN240
04-03-2018, 09:46 AM
Reviving an old thread. i have a pbm pipe for my sr20. I remember the pbm folks told me to only use a bottom mount exhaust manifold for alignment with the pbm cobra pipe.

Does anyone know any aftermarket brands of manifold that they've tried that fits perfectly with the pbm pipe? I've heard the tomei bottom mount doesnt line up well.. Is stock the only option?

I have Tomei manifold on my KA-T with the PBM pipe and it actually fits better than my hybrid sr/ka manifold.

S14DB
04-03-2018, 09:50 AM
Reviving an old thread. i have a pbm pipe for my sr20. I remember the pbm folks told me to only use a bottom mount exhaust manifold for alignment with the pbm cobra pipe.

Does anyone know any aftermarket brands of manifold that they've tried that fits perfectly with the pbm pipe? I've heard the tomei bottom mount doesnt line up well.. Is stock the only option?



A 3year old thread? Hell naw.