There seems to be a lot of questions and opinions about Stec manifolds rolling around out there lately. Some of the stuff said is opinion not really based in fact, and some of it is valid observations. I thought I would do a little write up since I'm constantly repeating the same points in different threads. I don't want anybody to think I'm trying to sell these for him though. People have just bashed them at times, or expressed interest in them other times. I think it's a pretty good option, but I'll try and stick to the facts about them and not "sell" them.

A little background so nobody tries to say I'm being dishonest, S-tec (Scott) built my car and is a friend of mine. He's an American dude living in Japan which is where his shop is. I used to hang out at the shop about every day, and have even helped stack these bastards up and test fit them with him, so I'm pretty familiar with them and how he checks them. I've run both his side mount and top mount manifolds. I'll try to cover all the good points as well as the stuff that could use some work.

RB20/25/26 Top Mounts

These seem to be the ones people are interested in the most here on NICO. The top mounts are basically a knock off of the HKS/Greddy twin scroll (split pulse) design T4 flanged design. All the piping is made with 321 stainless, which is much better then the 304 stainless most of the ebay crap out there uses, and it's all 2.8mm thick. There are also small braces where the primaries meet the flange, not that it needs them. They will never crack. He'll back that up. If they do, send it back to him and he'll fix it for you, but he's never once had that happen. I've had mine glowing bright orange (bright enough to read from at night time and light cigarettes of the exhaust housing) more times than I can count and never warped a flange or had it crack. The primaries are pretty will port matched to the head. Not perfect, but not half blocking the port like a lot of the ebay crap. The can't really be perfect because the 25 and 26 ports are a little different and it has to fit both.Also, the primaries go all the way through the flange, so you can really grind the crap out of them and match them up perfect if you want. I did it to mine.

The flanges are 12mm thick laser cut plate stainless, not cast, and everything is welded in a jig, so it'll be nice and flat which means no exhaust leaks. Scott checks each one with a straight edge and test fits every single manifold against a head before he sends it out. Also, they are flanged and drilled to fit both the 20/25 bolt pattern as well as the 26 bolt pattern, not that that matters to most people (it helps Scott keep the price down), but if you ever step up to a 26, you don't need to buy a new manifold. It'll slide right onto the head with out having to wallow out the holes like you have to on some mani's. There's one stud that would be a huge pain to get a nut on if it was stock, so you'll get a shorter exhaust stud to replace it and make it a WHOLE lot easier to get it all bolted up.

The wastegate runners are twin 43mm primaries coming into a 52mm collector, which necks down to a 4 bolt HKS style 50mm flange. As far as clearance of the valve cover goes, I've seen TO4r's, Holset H1E's w/18cm housings, HX40's with 16 and 19cm housings, ebay "Super T70's", and even a T88 fit on the stock T4 flange and clear both RB20/25 valve covers as well as 26 valve covers.

Now I'll talk about some of the issues people have brought up about these. One thing mentioned is the collector looks a little rough on the inside. It is. These are, in fact, made in china in a factory, all be it with much better materials than normal and with much better QC. Scott has actually flown to China and spoken with the dudes at the factory, showed them how he wants things, and paid extra for some of his specifications. He's also refused to pay them when they screwed up a batch and he basically had a pile of expensive scrap metal which he wouldn't ship out. These aren't "one off each time you order it" manifolds like 6boost or full race. Those are $1000-$2000 manifolds and they look like it. The collector on the Stec mani could use some work with a die grinder to smooth it out a bit and remove some excess material.

Here's the S-tec collector

Here's a 6boostObviously the 6boost looks much better, but I'm not sure how much difference it would make in flow.

Another thing about them is the fact that these probably will have clearance issues with left hand drive vehicles--specifically the wastegate flange will likely hit the steering column depending on the mounts you use. These manifolds are designed for a right hand drive skyline. I've seen them in a bunch of RB'd Sylvia's over in Japan, but again, they are RHD. You'll almost certainly need to have the wastegate runners chopped and re-welded to clear everything. That segway's me into another thing.....

The mani is a dual scroll (split pulse) design, but down at the end of the wastegate runners, the two halves of the engine pulses can come together and muddle a bit. How much this hurts is a subject for debate, but when I went to two completely separate wastegate runners and wastegates, it helped my spool times drop by around 200-400rpm in 4th gear. That's significant. If you are going to chop and re-weld the wastegate runners anyways for fitment, you might want to consider setting it up like this.

One last thing I'll mention is a problem that I have had, but I'm the only one anybody has heard of this happening to so far. I experienced boost creep on my RB25 with cams and a Holset HX40 with a 19cm housing and a single 50mm wastegate (one of S-tec's HKS knock-offs). Scott said he thinks it's because the HX40 with the 19cm housing was just the right balance of flowing enough to make a crap ton of power (and exhaust gas), but not enough to let out all of the exhaust gases, so the boost just kept climbing. Again, nobody else has had this problem. I took the mani off and noticed inside the collector, where the wastegate runners joined the party, it looked like the hole wasn't as big as the wastegate runner pipe (43mm). I took the die grinder to the ports and opened them all the way up (as best as I can tell with my precision fingerometer). After we reinstalled it, the creep issue was better, but the boost was still zipping up to 1.5 bar which is the size of the spring I had in there, staying put until around 7k rpm, then creeping up to about 1.8-1.9 bar by 7800rpm. To be clear, if you want to grind on them, you will need something like a die grinder and a stone. A dremel isn't going to even make dent in these things. The final solution was to take the mani off again, and re-design the wastegate runners into two completely separated runners with twin 50mm gates. As you might guess, I no longer have boost creep issues LOL. An added benefit was the better spool times.

In conclusion, the Stec manifolds are solid, quality manifolds at a damn good price. They aren't perfect, and do not have the same level of attention to detail during manufacture as some of the high end $1000+ manifolds but they aren't meant to compete with them. These are basically the best "budget priced" manifolds you can buy. I always say they are 95% of the high end mani's for 20% of the price. They fit and they won't crack, and I'll stake my "internet cred" (for what that's worth) on Scott standing behind what he sells 100%.

O yeah, here's the link to his site----> http://www.stec-motorsports.com/english/shop.asp


Modified by Cjmartz2k at 12:07 PM 11/26/2009

So, now on to the T3 flanged sidemount manifold.

They are made of the same 321 stainless that the top mount is made out of, but the primaries are a little thicker coming in at 3.0mm thick. Flanges are made to the same standards as the above top mount and also welded in a jig. These put the placement of the turbo in the exact same place as stock. If you can bolt whatever turbo you want up to a stock manifold, it'll fit on this one too. That means it's safe for LHD cars right out of the box, unlike the top mount. I ran one of these with my stock turbo and it bolted right up. Again, S-tec test fits each one up to a head and checks the flanges with a straight edge before it goes out. One thing I wish these were is split pulse (dual scroll) manifolds, but most of the smaller framed T3 turbo's you'd bolt on in the stock position are single scroll anyways (including the stock turbo) so it wouldn't help there anyways. Also they are already significantly improving how quickly a stock turbo spools, which is already pretty quick, so I dont' think it's that much of an issue. The primaries aren't huge, so while it'll outflow a stock manifold significantly, if you are chasing big HP numbers (like 500hp+) you might want to look at something else.

The one I had was heat wrapped for about 2 years and never cracked. I was running it in combination with one of S-tec's "turbo elbow's" and put a bunch of other things on my car at the same time, so I can't really say how much just the manifold added. I have spoken with a lot of friends who added the manifold last on an already completely opened up exhaust from the turbo back, and they said the difference was noticeable.

One quick story I thought was pretty cool and showed how resilient these things are. S-tec had some japanese drop his R32 GTSt off at the shop and say he was leaking tranny fluid all over the road every time he got up to speed and couldn't figure out why. Scott put it up on the lift and started looking for a leak and couldn't find one, although the entire underside of the car was covered in tranny fluid. I suggested looking at the fluid level, and when he did, the problem was obvious. Old dude had fill his tranny to the top of the shifter hole with tranny fluid LOL. Scott drained it, put the proper amount in, and put it up in the air on the lift with a poll on the gas in 5th gear and let it run for 5 minutes to make sure it didn't leak any more. After that was done and he was lowering the car, we saw this..........



Stock tune = to little timing and really high exhaust temps. Keep in mind that picture was taking during the day in a well lit shop. I've had mine glowing like that before too after a couple of back to back sets on a twisty road we call Takoyama. Anyways, that manifold is still on the same car to this day with no cracks or leaks or anything like that. They just won't crack. It's scary to think of what mine looked like under all that heat wrap when I had my sidemount on there and was beating on it. Must have damn near been white hot!
Modified by Cjmartz2k at 9:16 PM 11/25/2009

good deal CJ. I remember seeing in his other post that he would take a dremel to the ports if you had a 20 or 25 since it was meant more towards a 26. Did i understand incorrectly. I wouldnt be suprised if he meant YOU could dremel it instead of himself doing it.

EDIT. I just noticed there is already a 20/25 mani on sale right now on the site. Anything to say about that mani? says it will clear LHD cars but why are you unsure about the others?
Modified by synergy at 8:32 PM 11/24/2009

great writeup....We more info like this in the rb forums instead of people just slapping stuff on. Thanks and that looks like the manifold that i will be saving up for.

Synergy---I know Scott has taken a die grinder to some of the collectors before they've gone out. I guess if he doesn't like what he see's, he'll take 20minutes and fix it. As far as the ports go though, that's up to you, and a dremel isn't even going to put a knick in one of these things. You'll need a die grinder.

About that RB20/25 manifold you are talking about, I think you are talking about the sidemount which I'll write something on later today. Bottom line though, it's made with the same stuff, but it fits exactly like the stock manifold. Put's the turbo in the same place and everything.

Meet-- Glad you liked it man. I'm just sick of people confusing them with ebay crap, and me having to jump up and defend these things all the time. They aren't perfect, but they are far from ebay garbage.

It does appear to be a good alternative to the trash, its too bad someone dosen't stock them in the US. The cost of shipping (150?) if I recall was pretty brutal and really ramps that price up.

Evan

Thanks CJ... and whys everyone got a boner for a top mount? Side mounts are cheaper and they do the same job. Is there any proformance reasons why a top mount is better than a side mount?

Its not a big deal if nobody in the US supplys them if the maker in japan is willing to ship them

+1 for no middle man markup

Not sure what he charges for shipping, but I'm pretty sure if he can send them USPS priority from on base the shipping cost would be well under $100. That's just a guess on my part though, so don't go saying I told you he could do it. He used to be in the military, but is in no way connected with them anymore, so he can't just stroll on base and mail them. If he had to go through the japanese post office, then I could see it costing more.

Synergy--with the top mounts, it's about being able to fit a monster sized turbo in the space you have, ease of changing turbos, ability to make equal length manifolds (which I don't think these are), and most importantly, these top mounts have a provision to mount an external wastegate, and the side mounts don't. If you are going to install a GT30 sized and below turbo, and it was internally actuated, I'd look pretty seriously at the side mount, but it might require a spacer if the compressor housing is beg enough. I know people have side mounted holset HX35's before on stock manifolds, and this one gives you a little more clearance IIRC.

Yeah im looking at a stock t28 or a to4e with a slightly bigger housing.

I just want something to beat the evos and stis you know. Keeping up with the jones's

Hows the hood clearence with the top mount. no issues?

Hi people havent posted here in a while, but saw this pop up. Thanks for the write up chris, i am allways trying to improve what I have. As far as shipping, man i dont rip no one off, I charge people what it costs me. To ship ems from japan, yeah your looking at some money, but if you give me 4 days or so, I can always find someone to ship it from base. I do to canada all the time < thanks to some ikoti <idiot kid on the internet> and his big mouth> I have sold ALOT of manifold to canada recently. Its not always easy for me to ship them, but I help out people when I can. Please understand it was never my intention to sell to other places than Japan, although this is what has happened alot recently. Good thing is if you speak or type english you get to talk to me as I am the only American that work there, and I happen to own it. ]To answer someones question about what is so good about a top mount...well in theory nothing. long as yours fits on the side it is fine. Things come into play though. I have never seen anyone get over 430hp on a side mount s-tec motorsports manifold. There is a reason, the port leading to the turbo is small. little bit bigger than stock. It cant flow much more than stock at all, although the speed is greatly increased of the air, heat energy which ever you like moving through it. So it spools the turbo much faster than stock. I live in a place where people drift their cars daily, this is what the side mount was designed for response, I have changed some of the pipes over the years <which some of the changes actually made it harder to install> to make the turbo spool faster. If your looking to increase power with a larger turbo than stock this is not the manifold for you.There is a ebay sold one, that half fit and half dont, with 50mm collectors, but hey its cheap, i would take that gamble if you were trying to drag race, that is great for bigger turbos with a side mount. Only problem i see with it is it is made from chinese 301. Its going to crack, but it is still cheap so I would roll with it. Just buy a new one if it does.When ever my factory can get it so all pipes, and all flanges on that manifold fit to my liking I will sell it also, in 321. but they are not there yet. It is such a tight clearance manifold it is actually really hard to make and have it fit and easy to install. if you have a near stock turbo, and want instant response, a side mount is for youif you have a turbo that is large and you want some balls, get either a top mount or a cast bottom mount.

Thanks for your advise.

I guess id rather buy a top mount.

1. it looks cool.... thats a given.

2. Its only and extra few bucks to have the room to upgrade in the future.

Thanks for answering the questions scott.

Scott, you indicated that shipping was costly from Jp awhile ago, I wasn't inferring that you were "ripping anyone off".

I can get them to the states for about 65$, just takes a few days to do it, sorry if i overstated on the rip off thing, did not mean to infer thats what you were saying

$65 is very reasonable.

Evan

Just added a little something about the RB20/25 sidemounts in the second post. Check out the glowing mani pic

Have you thought about making the top mount lhd compatable without modifications? I'm taking it you are over seas, but someone in the states with this manifold could take some measurements and you could sell two versions of the manifold perhaps? one for lhd and one for rhd cars? I just looked at your site and I'm impressed, I had no idea these were so affordable. They really seem like a great piece.

EJ8 944 wrote:Have you thought about making the top mount lhd compatable without modifications? I'm taking it you are over seas, but someone in the states with this manifold could take some measurements and you could sell two versions of the manifold perhaps? one for lhd and one for rhd cars? I just looked at your site and I'm impressed, I had no idea these were so affordable. They really seem like a great piece.

I'd be more than willing to try out and see what mods are needed to convert the top-mount manifolds to LHD for you, I know a muffler shop owner who converted a "XS Power" turbo elbow to work LHD for me, and the new(ish) piece is a thing of beauty.

My issue is the lack of steady income to buy one till mid-December, but running an externally wastegated t04e is next on my to-do list for RB25.

S-Tech

was looking at the turbo elbow for the stock RB25 on your website and was wondering if these will work with a LHD rb25 swapped state side 240?

bump -- I'm trying to order one of the sidemounts, but how do you pay? I went through checkout, and I've got an invoice, but nowhere to pay.. I figure he's trying to source someone to ship?

I just emailed him about it and sent him the link to this thread. I'm sure he'll get back at you soon, but remember it's like 3am there now.

If I knew for sure this would not interfere with the steering shaft I would have already bought one .I get my engine from the machine shop after waiting 2 years at the end of this month and will be needing a mani for my hx40 rb25 swap.I was going to go with the 6 boost but I would concider this one as well.

Thanks, got a response from him. Can't wait for this to come in! It's the sidemount, so hoping for an easy bolt-on upgrade (LHD).

Please post your results! Pictures included

Has anyone tried fitment on a Datsun? Also--- has anyone run this "ebay style" wastegate and proven its performance? I would rather run a tial, or the HKS unit but the HKS number is almost 700 bucks!
Modified by streeteg at 7:56 PM 2/2/2010

No clue on the Datsun from me, but the wastegates are good to go. The reason he started selling the wastegates was more than a few of us started coming into the shop with ebay knock off wastegates that wouldn't seal well. Also, real HKS or whatever name brand wastegates are like $800 a pop in Japan. He basically took the ebay knock off design of the HKS 50mm WG's and had the maker do a couple of improvements to what they had been making, and had them quality control them before they sent them. It costs him a little more (which of course he passes on to the consumer) but it's worth it. He also checks some of the lot (not every single one like the manifolds though) before they leave. I ran one for about 2 years, and then two different ones (at the same time) for another two years with out any problems. I know of 4 other people running them on Okinawa that had zero problems with them also (including another twin gate set up like mine, so I guess that's 5 gates total besides mine I know of personally).

^^emailed

i was wondering, i have a R32 GT-R and im looking for a manifold for my RB26

the choice is between XS Power vers 2 , OBX and this one

i will be using a GT4202 turbo with a 1.15 a/r will it clear everything with this manifold ? its a pretty big turbo with a big a/r

Hmm, I've got no idea about that one, sorry. I can only say 100% on the ones I've seen actually installed on the manifolds. Maybe I can get by Scott's place and take some pics with a straight edge on the installed manifold to get some kind of idea on the clearance.

Cjmartz2k wrote:Hmm, I've got no idea about that one, sorry. I can only say 100% on the ones I've seen actually installed on the manifolds. Maybe I can get by Scott's place and take some pics with a straight edge on the installed manifold to get some kind of idea on the clearance.

ok thx

do you have his email so i can maybe check. I really need to order a manifold so i can start my single turbo conversion. But as i said im a bit worried about if the Garrett GT4202 with a 1.15 a/r will fit. Dont even know if it will clear with the XS power or OBX manifold either.

This is the turbo i will be using. Its on a 2JZ-GTE in the pics btw
GT4202 // inducer 74.7mm and exducer 102mm

now looking at the pics you have, that turbo might just fit. Im not sure if you looked and my photoshop pics but the reason my turbo didnt fit was b/c the turbo itself stuck out pass the 2 bolt holes on the t4 turbo flange(the 2 holes closest to the valve cover) The way the turbo in the above pics are designed the turbine house leans toward the valve cover(on the supra, away from the cover on the rb's) which means the compressor houseing is on the opposite side of the bolt holes. Man I would really like to have that turbo on my rb....ewwwww ahhhh

Sorry for the possible run on sentences...im not to bright.lol

DO IT!!