Top VS. Bottom MOUNTS

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Silvia_Freak
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Hey guys..Just wanted your reviews about Top mount and Bottom mount manifolds....Which is better?


frsh13
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The quality and design of the manifold matters more than if it is top or bottom mount. As far as I know the only good bottom mount manifold for the KA is the AMS one, and the Revhard.

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s14_240sx
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Alot of people cheap out and buy th ssauto**** top mounts, which are horribly made and don't have enough support so they crack. but it won't matter if you spend the extra money and buy good ****.

S13FX
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s14_240sx wrote:Alot of people cheap out and buy th ssauto**** top mounts, which are horribly made and don't have enough support so they crack. but it won't matter if you spend the extra money and buy good ****.
Thats a false statement right there. Because there is just as many people out there that buy them and use them with no problems.

I did on my CRX worked perfectly, the turbo gave up before the mani did.

frsh13 s13 said it though, if the mani is reliable and good shouldn't matter if it's top or bottom. Bottom mount however might make it easier to fab up the down pipe.

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WDRacing
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Bottom makes for an easier downpipe...thats all there is. If you take similar manifolds and compare them, there will likely be little to no difference.

Also for the record, Banks uses log manifolds with ALL of there turbo kits, to include the one that makes 1500WHP. So this BS about logs being bad is exactly that...BS.

Don't believe the hype just cause it was posted on the almighty interweb. Unless of course I say it, then it's 100% fact.

WD

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480sx
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Logs dont put down the torque that a tubular manifold will, but typically have a tinnnyyyy bit faster spool.

Also no ones said anything about weight distribution. Top mounts put your center of gravity a bit higher than stock which really isnt what you want, while bottom mounts keep things a bit more balanced.

S13FX
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WDRacing wrote:
Don't believe the hype just cause it was posted on the almighty interweb. Unless of course I say it, then it's 100% fact.

WD
Well I dunno about 100% but maybe 99.9% but even then it's ok cause I make up for the .1% HAHA

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Florida240sx
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Just remember WD is always right, if not he'll rig something up to back his "previous false" statement.

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spooled240
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480sx wrote:Logs dont put down the torque that a tubular manifold will, but typically have a tinnnyyyy bit faster spool.

Also no ones said anything about weight distribution. Top mounts put your center of gravity a bit higher than stock which really isnt what you want, while bottom mounts keep things a bit more balanced.
So theres a small difference in the lag between the log style and the tubular? It seems as though the log-style manifolds are a bit quieter, more durable and dissipate less heat than the tubular types which are some other reasons for using the log mani.

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480sx
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Yea, but i wouldn't imagine it would be very noticeable. Think about it, with a log theres a smaller area to fill before it hits the turbine. With a tubular theres a bit more.

KATwo40
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I used a "crappy SSAC" T25 bottom mount, modified it to be a T3/T04E manifold and I absolutely loved it. Weight was kept lower, underhood temps near the brake reservoir were lower, downpipe flow was MUCH more linear, and I got fantastic spool. Made 15psi @ around 3500rpm with a .63 a/r exhaust housing.

Here are some pics.








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boznuttz
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Pioneering.

S13FX
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Ok, if you guys want keep loading this thread up with INFO.

I'm going to add it to our sticky up top.

Seems like there is a lot of good info in here.

Great job guys.

Thanks,Mike

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boznuttz
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I had an SR T25 off of an SSAC bottom mount manifold and there were no problems. The Elbow off the turbo had a lot more clearance from the BMC.

By the way guys, I'm selling a few bottom mount manifolds since I have them laying around my room.

*INTERESTING FACT*T2 bottom mount manifolds do not make good pillows. They also have the potential to stub my toe everytime I walk by my car parts 'pile'.

r3skyline
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jordan gladman sohc manifold..45*bottom mount with external wastegate. never cracked been running for over a year. very good design but needs elimination of a/c.

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new_to_drift
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what are some other reliable turbo manifolds? ive been researching, and im almost positive im lookin at a bottom mount. From what ive read people have had bad experiences with SS autocrome but at the same time many like them. If i got one of those and ensured the welds were good would that be enough? im only going to run a t28. I have searched but this is the only question I have. Thanks

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GEO
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Bottom Mount keeps the engine bay alittle cooler.

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neverlift
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I have an ssac that is so ****ty it has been threw like three turbo installs on 3 cars. Its about to get mod'd like shown above for a t3. IF dood ever comes thru with it...

I have had to re weld one support tab that I thought looked suspect(looked like the welder didnt use enough filler) but overall for the 30bux I paid it was worth every penny, and the guy before me was tough on it for sure, some may know him ichi go...

as for cheap vs pricey , I know 2 guys with quality manifolds that both cracked in the same spot. Both are top mount and t3/4, and both over 300whp. IIRC its something to do with the type of ss used in most manifolds, as to why they crack. Most 'quality' manifolds are made from the same ss as the ebay ones

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new_to_drift
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when it comes to top or bottom mount manifolds, what is the difference when it comes to turbo outlet/ downpipe? from what ive seen all downpipes are the same

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480sx
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Contrary to what you have seen, all downpipes are different. Each turbo manifold puts the turbo in a slightly different spot making it so your downpipe is a bit different on each manifold. Topmount manifolds make it so that running your downpipe is harder than a bottom mount.

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Jookmasta
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how about neither? i run a side mount log mani and have been doing so for the past 3 years lol. it's cast iron tho so no chance of cracking and has held up well for me. if i had to do it again, i'd go with the bottom mount only because the DP routing is much nicer and the less temp u have near the brake reservoir, the safer it is i feel. both designs have proven themself to be reliable in their own good but u have to take everything with a grain of salt. quality control on the materials used to form the manifold are kinda out of the hands of the person who welds em up or who distributes em. anyways, those are my thoughts on it.

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480sx
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Lol @ sidemount

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Jookmasta
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u know, i honestly i think i might be only person here on NICO to have a sidemount mani lol.

ken240sx
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I'm bringing this thread back to state that side mounts are great. BMW uses some sidemount manis on their newer 3 series and it makes the turbo's sit about 1 1/2" from the exhaust ports, which helps reduce the lag a little.

I'd say bottom mounts allow for a little better engine temps and clearance issues with the DP, MC, strut bar, hood, etc.Top mounts allow for much better access to the turbo and easier disassembly, but have more problems with clearances and melting ****.The advantage of the tubular manifold is when it is truly equal length. The equal length allows the exhaust pulses to not interfere and bunch up to create hot spots. In theory a true equal length tubular mani should allow for slightly better spool than a log, but if the log mani if quality and it allows for the turbo to sit close to the head so exhaust doesn't travel as far, it will aid in spool up time.I'd say a quality equal length and a quality log are not going to be that much different for spool up times, logs tend to last longer cause many are made out of thicker, stronger metal.I'd also like to put out that a cheap-average log mani probably won't perform as well as a cheap-average equal length(tubular).

+1 for having a sidemount Jookmasta

Ligerzero
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Ebay manifold with a t3 flange welded on as well as an external dump and flange for the wastegate....


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Reno
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http://cgi.ebay.com/ebaymotors...26r30

yes??

the turbo can sit even lower now YAY LOL

damn should at least include some gaskets...

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boznuttz
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Another SSAC T2 bottom mount with a tigged on T3 mount to house this beast T3/T4oe.

Lol, the 3rd and 4th injectors aren't firing, I need to replace the dented and bent oil pan, and I need to make a new exhaust piece. Other than that, just little things here and there to get it all nice and fun!

VVV

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DMan II-40
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I made a thread about the SSAC T2 eBay mani, Kinda just to get ideas on how to make them more reliable. List i have so far isnt much, but it includes slotting the runners for heat expansion, using a DP with a flex section to reduce stress, and last possible idea i had was to weld support bars in, i drew up an idea. Someone said reweld the whole thing but that is to much work for a cheep mani in my mind, but if you want go ahead.

Everyone I have heard of getting them as like them so far with a couple exceptions. And for $100 I don't think it is a bad buy.

Edit: forgot to link the thread if anyone is interested. zerothread?id=346538

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WDRacing
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Ligerzero wrote:Ebay manifold with a t3 flange welded on as well as an external dump and flange for the wastegate....
AWSOME man...very well done.

WD

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spooled240
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man that's really neat tucking that big *** t3/t4 on a bottom mount. BUT is your wg flange only tapping into the exhaust header runners from cyl 1 and 4??

How much does this cost and how difficult is it? (bottom mount t2 manifold --> a bottom mount t3)


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