Manifolds: Tomei Expreme vs Ichiba VII

[cdvr-s13]

How do these manifolds compare in spooling?

The tomei has a divider at the flange for the turbo, and the ichiba doesn't. Will this make a huge difference?

http://i1.frsimg.com/images/detailed_images/Ichiba_NS-12015_01.jpg

vs.

http://i2.frsimg.com/images/detailed_images/Tomei_193086_3.jpg

[BlitzRPS13]

Tomei FTW.

[abunai the drifter]

dose the spilter make that big of a differance???

[S13 curtis]

damn that tomei looks restrictive

[cdvr-s13]

damn that tomei looks restrictive

Apparently its the best flowing bottom mount manifold for SR?

[Hashiriya415]

Separates interfering cylinders to give you the most gas to the turbine

[Hashiriya415]

By the way I do have the tomei expreme mani, and I'm thinking about selling it, PM your offer

[PoorMans180SX]

damn that tomei looks restrictive

Clearly you don't know anything about Exhaust flow.

Considering the Ichiba is a knock-off of the Tomei, I'm betting the Tomei is better.

The "splitter" is there to keep exhaust pulses separate, helping spool your turbo faster.

[S13 curtis]

Clearly you don't know anything about Exhaust flow.

Considering the Ichiba is a knock-off of the Tomei, I'm betting the Tomei is better.

The "splitter" is there to keep exhaust pulses separate, helping spool your turbo faster.

I been knew that bro, im just saying it "looks" restrictive because ive seen other tomei expreme manifolds and it dosent have the oval look to it. i wasnt talking about the divider. NOW DO YOU SEE !

http://www.tomei-p.co.jp/_2003web-catalogue/000_expreme/each-product/each-product_img/sr20det_exhaust-manifold/ph_frange_up.jpg

[PoorMans180SX]

Ummm...I guess? It's kind of misleading to say it "looks" restrictive, when you know full well that it flows better, am I right?

I apologize.

[codyace]

Just extrude hone your stocker - cheaper, more reliable, and no worries!

[guitaraholic]

More reliable I would have to go with, but cheaper, I'm not sure of. I think extude/hone services usually run around $350-$600. Please correct me if I'm wrong.

[usdm180sx]

Are you fucking serious? If you don't mind always working on your car get the isis one cause that shit will crack all day long so you'll always be fixing it. Or get the Tomei and call it a day...until it cracks because some do, or get your oem shit extrude honed for $350.

I picked up an HKS turbo exhaust manifold for $400 off ebay. Shit's solid with short runners and I've never seen them crack. But then again I'm in So Cali and the weather isn't as extreme as the Northeast

[cdvr-s13]

Are you fucking serious? If you don't mind always working on your car get the isis one cause that shit will crack all day long so you'll always be fixing it. Or get the Tomei and call it a day...until it cracks because some do, or get your oem shit extrude honed for $350.

I picked up an HKS turbo exhaust manifold for $400 off ebay. Shit's solid with short runners and I've never seen them crack. But then again I'm in So Cali and the weather isn't as extreme as the Northeast

I don't even know who you are ranting at. Nobody even mentioned ISIS in this thread. The ISIS isn't even an unequal length manifold, which we ARE taking about. Plus I doubt the ISIS is that crack happy. I'd rather have an ISIS over my Megan, and my Megan hasn't cracked?

I'm going to look into extrude honing my stocker, although I'm sure its like $500, in which case I'd rather just get a tomei.

My main question was though, does the divider make that big of a difference? the price difference between these manifolds is $250 or more depending on what kind of deal you can find on the Tomei. If the difference is only making boost a few hundred rpm sooner, its still a pretty good mani right?

[usdm180sx]

My bad ichiba Isis Megan I never bothered to research the difference because those companies aren't my cup of tea. Since I read a few cases of tomei expreme mani's cracking I would just assume the knockoff's are even worse.

[PoorMans180SX]

And it's a total knock-off of the Tomei. I helped my friend put his Tomei on and fit and finish are spectacular.

You see how the top/longest pipe of the Ichiba is bent? It's around the others and comes down at an angle, whereas the Tomei goes over the top. This makes clearance a lot better, which will make it way easier to install. Have to think about these things.

[slider2828]

ERgh... who really cares about divorced chambers since its a bottom mount T28, none of those turbo's have a divorced outlet.... so truthfully who cares... its pretty minor if you you even see the difference at all....

Like cody said, stock manifold honed would probably be the same performance....

[codyace]

More reliable I would have to go with, but cheaper, I'm not sure of. I think extude/hone services usually run around $350-$600. Please correct me if I'm wrong.

Expreme's are 600ish bucks
Extrude hone (iirc) is 400ish.

Expremes are nice, but really don't' offer much of a 'gain' over the stock one in this area...there is only 'so much' you can accomplish with a T2 flanged bottom mount unit. To me, the differences in power are little at best.


Lets put it this way...I offered to put my manifold up against Full Race's about 2 years ago...and do it at Evans Tuning (a tuner they deal with). The deal was all said and good, and I even offered to buy it cash on the spot if it was better.

...that was until he wanted a 'tunable' EMS on the car to 'help use it to get the full potential out of the manifold'. I called bullshit, and said they would change the tune to make it 'make' the HP, and exclaimed 90% of the SR world runs on a ROM ecu. Needless to say the deal fell through at that point - which to me basically says it wouldn't out perform their product. Take it for what you want, but that was my experience with them.


You just can't beat the stock extruded manifold for our cars...sure it doesn't look as nice, but who cares. Function > Form.

[djcobra]

^^ I agree with Codyace here as do many other users on this forum... I've had my Tomei manifold crack while on the bloody dyno, was I hella pissed? Damn right!

I'm rockin' the Stock Manifold and I ain't going back to the tube crack-o-folds lol...

Steve.

[codyace]

^^ I agree with Codyace here as do many other users on this forum... I've had my Tomei manifold crack while on the bloody dyno, was I hella pissed? Damn right!

I'm rockin' the Stock Manifold and I ain't going back to the tube crack-o-folds lol...

Steve.

crack-o-folds...love it!

[boost]

so i'm guessing you didn't get a good comparison dyno of the tomei vs stock?

[Silverbullet]

ERgh... who really cares about divorced chambers since its a bottom mount T28, none of those turbo's have a divorced outlet.... so truthfully who cares... its pretty minor if you you even see the difference at all....


The difference probably is minor but having a divorced chamber manifold and divided turbine outlet don't really have anything to do with each other, other than the fact that they both make the turbo work a little better.

The divorced manifold chamber cleans up the flow of the product going into the turbine, while the outlet divider cleans up the flow going out of the turbine.

[koukie180]

OP, you already know which one is better. Psychologically, you are just trying to justify spending more for the Tomei. Why would you go something LIKE TOMEI, when you can get TOMEI.

If money was really the issue for you, stick with stock. Don't even bother with extrude/honing and all that crap. It will just reduce the thickness of your porous cast iron manifold and increase chances of cracking.

If performance is what you are looking for, Tomei has much nicer welds, quality hardware, includes heat wrap, and not prone to cracking. You get what you pay for, not a dime less.

[garagelu]

OP, you already know which one is better. Psychologically, you are just trying to justify spending more for the Tomei. Why would you go something LIKE TOMEI, when you can get TOMEI.

If money was really the issue for you, stick with stock. Don't even bother with extrude/honing and all that crap. It will just reduce the thickness of your porous cast iron manifold and increase chances of cracking.

If performance is what you are looking for, Tomei has much nicer welds, quality hardware, includes heat wrap, and not prone to cracking. You get what you pay for, not a dime less.

man, your post has so much fail in it. Extrude honing reducing the thickness of the manifold and increasing the chance of cracking....wow. The amount of material they take out is not going to affect the strength of the manifold at all.

And the Tomei is prone to cracking just as much as any other manifold. And it's not only about the welds. The material they use and the thickness of the piping has a lot to do with it as well. The main importance in these bottom mount tubular manifolds is the bracket connecting the head flange to the turbo flange. Without that bracket, your manifold will only last a few weeks, if that.

[koukie180]

The amount of material they take out is not going to affect the strength of the manifold at all.

Sure give me proof. I have had my stock extrude honed. Spent the extra money. Not so long after, the inside of the manifold crack.

Also, keep in mind the gains from extrude honing is not that much greater, why spend money to increase the chance of cracking.

reducing the thickness of the manifold and increasing the chance of cracking....wow. The amount of material they take out is not going to affect the strength of the manifold at all.

You fail in school. Reducing thickness of any material will weaken it.

The main importance in these bottom mount tubular manifolds is the bracket connecting the head flange to the turbo flange. Without that bracket, your manifold will only last a few weeks, if that.

You fail again. So you're saying even a Megan manifold that has a bracket will be just as good just because it has a bracket?

[koukie180]

I don't doubt that Tomei manifolds do crack. A friend of mine overheated his engine and his Tomei manifold cracked. It was wrapped with the provided heat wrap. A little too much EGT and there goes an expensive manifold.

My experience with the Tomei manifold has been good so far. I did not use the heat wrap. I sent it out the be ceramic coated internally and externally. The EXPREME label fell off, but obviously 4 tack welds are not going to hold it. I have not overheated once with that manifold. I occasionally hit my downpipe (at most once a day) on the speed bump where I live. Still no cracks.

I do my own ECU tuning with wideband, speed density, and egt. Running lean can increase EGT substantially in a small amount of time. A high EGT is what will break/crack your manifold. Even a bracket can't save your manifold.

[codyace]

so i'm guessing you didn't get a good comparison dyno of the tomei vs stock?

No I didn't - because Full Rce essentially 'backed out' of a free deal over the issue of a tunable EMS. Goes to show you that dollar per dollar, they knew they coudlnt' outperform mine.



If money was really the issue for you, stick with stock. Don't even bother with extrude/honing and all that crap. It will just reduce the thickness of your porous cast iron manifold and increase chances of cracking.


Where did it crack? On the Divider? Hell every OE manifold known to man has a crack there, I think it was more in their casting process. Even guys who have port n polished them have had this crack appear. If it cracked anywehre else, then it's certainly not an issue on Extrudes Fault. Plus you can tell EH to retain the center divider as well if you're afraid.

Crack to me, is the typical 'tubular' crack. The base flange, a runner, the merge...not that lil riser crack in the OE one lol, it matters not at all.

PS: EH doesn't remove much material either, just the rough coating. PnP jobs probably hog more material away.

[PoorMans180SX]

To me, if you really want a good bottom mount, you have to pay for it. $800 will buy you a lifetime warranty against cracking with a Synapse Manifold:

http://ep.yimg.com/ca/I/yhst-1164098593086_2093_1698985

http://ep.yimg.com/ca/I/yhst-1164098593086_2093_1755509

Dyno (stock vs synapse, back to back run, 8psi, peak gain of 16whp):

http://synapseturbo.com/gallery/cache/d33c5f08f8dd5ddeca205585f9aa465b6ed19d11_800.jpg

[Tearlessj]

Meh, $800 for 16hp. Or you could go honed and probably make close to the same power for half the price.

[MadScientist]

Stock Mani is a cast unit... Cast metals hold heat. Thermal wrap will make this worst.

SS Main will dissipate heat faster and make engine bay temps cooler. Thermal wrap on SS helps even out heat dissipation and prevent cracking.

I have been considering placing a T3 flange on the Tomei.

[rc1honda]

Meh, $800 for 16hp. Or you could go honed and probably make close to the same power for half the price.

True but if it breaks you get a brand new one. But the problem is still there i guess. If you crack one with current boost and tune your going to crack another.

[clark]

my experience:

bought an XS power mani on ebay. construction looked fine and was extremely cheap. i can't imagine a megan or isis manifolkd being of much better construction.

mine did not crack, however it warped at the flange that mates with the cylinder head. it warped so bad it snapped an exhaust stud because there was too much stress which then created a huge exhaust leak, which is how i found all of this in the first place.

put back my handy dandy stock cast manifold (thank god i kept it) and i've been rocking that for a year now.

i can't say anything about the unequal length tomei expreme style manis, but the equal length really isn't for guys who have the stock turbo (me).

i get MUCH BETTER response using the stock exhaust manifold. like an idiot i threw the stock exhaust mani heat shield away. does anyone want to sell me one?

i am completely with codyace on this one. for those guys who don't know what extrude honed is, don't pretend you know, just look it up.

unless you plan on running high hp, don't bother with an exhaust manifold upgrade. the only thing you really need to do is upgrade your exhaust outlet elbow divider o2 housing, call it what you want.

wow that was alot of info.

[codyace]

Stock Mani is a cast unit... Cast metals hold heat. Thermal wrap will make this worst.

SS Main will dissipate heat faster and make engine bay temps cooler. Thermal wrap on SS helps even out heat dissipation and prevent cracking.

I have been considering placing a T3 flange on the Tomei.

What a ton of misinformation here...

Heat rentention in the manifold HELPS performance, as through the ideal gas law, all of that hot air wants to race out and into the much cooler exhaust, thus helping spool up and performance (amongst other physics things that I've since forgotten). This is where the stock manifold shines, as it really keeps all the heat trapped in the manifold, and if properly coated (i prefer swain) REALLY helps keep heat out of the engine bay. Double win.

With a tubular manifold, you do dissapate heat yes, but all over the engine bay. Remember, heat isn't exactly 'lost' ya know? Why would you ever want it out of the exhaust path and burning your master cylinder and associated stuff is beyond me.

Lastly, the inherent design of the tubular manifold isn't beneficial in regard to spool up or torque. This sucks if you ask me. Sure it may free up a few more top end ponies (i'd venture to say 5-10) on the top end, but to me that is not worth the lost torque throughout the midrange. Exhaust manifold design is backwards of intake manifold design..

PS: Be careful of adding a flange to the bottom mount manifold. Space is already at a premium with a 2871, imagine with a 30r in there and a larger compressor housing..you'd be into the engine mount and engine block itself. You'd probably be best off adopting to a top mount.



unless you plan on running high hp, don't bother with an exhaust manifold upgrade. the only thing you really need to do is upgrade your exhaust outlet elbow divider o2 housing, call it what you want.


This is IMO very important. To me, it makes total sense to spend the money on a quality (greddy for example) o2 housing that fits and won't have issues, than on a tubular manifold

[koukie180]

Indeed.

To further explain what codyace said. Heat wrap does not dissipate heat. It retains the heat within the turbo manifold. At high temperatures, molecules travel at higher velocities and therefore increases the pressure of the system. At high velocities and pressure, the molecules have more energy to propel the turbine wheel. This will give you faster response and power. However, a downfall of heat wrap is the high retention of exhaust gas temperature increasing the chance for cracking rather preventing it.

[koukie180]

My extrude honed stock manifold had a crack where the divider is. I have had 2 other stock ones and never had a problem. Unfortunately I didn't have a good experience extrude honing for a stock manifold. I'm sure it can be used in other type of alloy to improve flow and still retain strength.

For what it's worth, I would stick with a stock manifold without honing if I didn't have a Tomei manifold. I just wouldn't want to spend that extra $300 again for extrude honing and find a crack later.

[codyace]

The funny thig about 'the crack' on the divider, is that it's also found on GTiR and Bluebird manifolds as well, even IF purchased brand new before extrude hone (yes, I've got crazy friends that work with new only stuff...i'm not that baller lol!). I really wonder if it's just in the casting process or what that makes it crack there. Never EVER have had an issue on the 50 or so people that I personally know who've had it done on FWD and RWD manifolds. Just one of those things I guess?

[PoorMans180SX]

I'm agreeing with what you guys say for the most part.

Here's the thing. I'm betting a coated tube manifold will outperform a stock one on all points. And stainless steel actually retains heat very well.

Why do you think a twin-scroll tube manifold works so well and spools so fast? Because it flows gases more efficiently. This is kinda the same thing as going from a stock or non-equal-length manifold to an equal length tube design.

Now I can totally understand where you guys are coming from with bolt-on turbos, but it almost seems like you guys are saying that the stock manifold is superior to all tube manifolds, which is not really true.

[codyace]

I'm agreeing with what you guys say for the most part.

Here's the thing. I'm betting a coated tube manifold will outperform a stock one on all points. And stainless steel actually retains heat very well.

Why do you think a twin-scroll tube manifold works so well and spools so fast? Because it flows gases more efficiently. This is kinda the same thing as going from a stock or non-equal-length manifold to an equal length tube design.

Now I can totally understand where you guys are coming from with bolt-on turbos, but it almost seems like you guys are saying that the stock manifold is superior to all tube manifolds, which is not really true.

In regard to bottom mount off the shelf manifolds with T2 turbos, I am saying stock is best (with extruding). You can't really compare stock to anything top mount as it's completely different ball game. I will argue forever that you just can't beat it for a run of the mill sub 400 hp street car. A track car is completly different- like I said when you can take advantage of consistent RPM's and or a raised limit, then I'd be all for the tubular setup to use the 'specific' powerband. For a street car again, you're not going to beat the midrange torque that the stock manifold creates.

And in regard to 'twin scroll' the stocker is as well...but when you're not dealing with true tang housing, it really makes zero difference. Again, if I was running a T3 flanged top mount turbo setup, it's tubular all the way. If I just want a fun 350 whp and no worries, stock is king.

[PoorMans180SX]

Right on. I totally agree.

[codyace]

Right on. I totally agree.

Fair point to bring up, as I dont' want people thinking a T2 stock manifold is better than a nice tubular top mount setup heheh.

[dookiedang]

has anyone tried the GT Spec? so far they looked really good and thick. my buddy got one on his evo and so far so good. but i havent really heard a review with them on the sr's yet. if anyone got any info post it! thanks

[garagelu]

I've got GT spec's turbo elbow and its really nice quality part. It looks very close to the tomei expreme elbow. May even be from the same manufacturer.

[anton1o]

Codyace is exactly on the money, standard manifold has proven it self so many times on vehicles even upto 300rwkw.. As i know somebody with Standard Manifold + TD06 making 300rwkw.. The vehicle is very responsive.

Changing SR manifold's imo are only useful when going high mount, if your staying low mount keep it standard.. If your after a responsive setup without adding more lag to the mix to gain a few more HP then standard is the way to go!

[brian3676]

Its a T2 flanged manifold you guys are talking about, Stock is fine, you might get a few more HP out of a Tomei or something, But its still pointless, No T2 flanged turbo is gunna out flow a good reliable honed OEM manifold.

[reccakun08]

has anyone tried the GT Spec? so far they looked really good and thick. my buddy got one on his evo and so far so good. but i havent really heard a review with them on the sr's yet. if anyone got any info post it! thanks

thats what i heard from a subie guy that the gt spec mani are same manufactures of tomei.

[HemiCharger]

I had tomei and I now run the extrude hone stock manifold and I could not tell any difference among them. As far as a down pipe-- I love my DMAX all in one cobra elbow downpipe -- every one should have one.....

[PoorMans180SX]

Please don't post things if you don't know them as fact. Thanks.

Now, if you look, the Tomei is pretty much the same design as the stock manifold. Tomei builds all their own stuff btw.

An equal length will technically flow better, but will have slightly more lag due to the longer runners losing heat.

Now stop bumping this thread with misinformation.

[sidewaysil80]

The main importance in these bottom mount tubular manifolds is the bracket connecting the head flange to the turbo flange. Without that bracket, your manifold will only last a few weeks, if that.

shit i'm setting a record then with my megan. i don't have the bracket installed and i've been going strong for like 2 years. i can't really get in on the stock honed/extruded debate because honestly i only recently heard of it. but fwiw, if even the top dollar manifolds crack (which they do), why waste the money on one? just get a mid-ranged one...or find a top dollar one with a warranty...