Neo

I agree, Ross. Some people like the coffee can look, but I will never understand that. Others will base their opinions on no data at all, and that's just plain stupid.

Dave (SMSP) is a straight-up guy, does great design work on headers and exhaust systems, is a pleasure to deal with, and sold me one kick-*** exhaust system for my GSR. In my book, SMSP gets major !!!

00MRSi

I too am surprised by some of the stupidity/ignorance I read. As mentioned, this is a CUSTOM exhaust designed specifically for the ITR. The RESTRICTIONS have been carefully removed and the system is made for "stealth-like" appearance and lowered sound decibals. This system is top notch. You should LISTEN and LEARN before making assumptions..

SMSP

This is an interesting thread to say the least. Everyone is entitled to their own opinions....even me. Thanks to the guys with the + comments.

Here are pictures of zyg's exhaust which is very similar to George's except I used (2) 45 degree bends before the axle on George's versus zyg's (1) 90 degree bend. Both of these exhausts used 2-1/2" tips. The exhaust on the yellow ITR used the stock tip which could be adjusted slighlty more for direction. Please note that the stock ITR tip on the stock ITR muffler is welded on at an angle.




I always read that exhausts don't give any power just noise. This is probably true in most cases. But not all exhausts are built the same way. When I spec and build my exhausts I also take a common sense approach to it. One thing I know that's true is that just because a system is flashy does not mean that it will perform and make power. I also don't like to use silencers since they defeat the main reason (to me) for buying an after market exhaust and that is to release more power.

Most of the JDM systems are 60mm OD (2-3/8") some of the US systems are 2-1/4" (Thermal, Magnaflow and Comp Tech). The new Type One is 63.5mm OD (2-1/2") and the Kakimoto R is 70mm OD.

I'll try to give some comparisons between these systems. I can't comment on the HyTech system since I've never seen one but I suspect they do some of the same things I do because it's the right way to do it and they'd take the extra time to build it that way.

My exhaust is 2.50" OD, 16g 304L stainless steel with an ID of 2.37". I use a straight thru Magnaflow 2-1/2" resonator and muffler. There are no bottlenecks and no joint/section is smaller than 2.37" ID. However, 2-1/2" cats have a 2-1/2" ID outlet and this would cause a mismatch with 2.37" ID tubing. So I taper flare the inlet of the B pipe and use the exact same flange as I do on my cats.



Therefore the ID of my B pipe inlet is between 2.50 and 2.56" and thus no mismatch. In the above picture of the exhaust system, if you look at the flange set up for the muffler you'll notice the tubing of the B pipe extends past the flange and gets inserted into the muffler inlet. This is done to prevent any chance of the flanges from misaligning and causing turbulence at that point.

How does this compare to other systems available?

Stock ITR is 57mm OD (2-1/4") with multiple bottle necks. The worse being at the B pipe inlet which is 1-3/4" ID. The B pipe necks down to around 2" or 2-1/16" OD at the B pipe to Axle back joint and the muffler tubing is 54mm OD and then necks again to 52-53mm right before it enters the muffler.

Tanabe RM is 60mm and has a 1-7/8" ID x 2" long bottle neck at the B pipe inlet and it's resonator uses perforated dog ears that extend into the flow path. The 2 joints after the resonator are 2-1/4" ID.

APEXi is 60mm and has a 2-1/4" ID at the B pipe inlet, I'm not sure of the rest of the system but I believe the 2 other joints would also be 2-1/4" ID.

Comp Tech, Magnaflow and Thermal are 2-1/4" OD systems like stock but without the bottle necks for the most part.

Kamimoto R is 70mm OD and has a B pipe inlet ID of 2.50" ID but the resonator is not a straight thru from what I can tell from the picture.


Type One is 63.5mm OD (2.50") with a 2.37" ID in the tubing. However, the B pipe inlet necks to 2-1/4" and then opens to the 2.37" ID, the resonator is straight thru but the flanged joint after the resonator is also 2-1/4" ID. The outlet of the B pipe (for the axle back joint) is set up to bolt to stock or the Type One axle back to bolt to the stock B pipe and therefore uses the stock donut. This tubing necks down to 2" OD with a 1-7/8" ID.

N1 Axle Back is 60 or 63.5mm OD and has a 2" ID inlet in order to bolt to a stock B pipe. (This is the joint that Ross was talking about having me fix).

So, I feel my exhaust performs well because the muffler and resonator are straight through with nothing protruding into the flow path, there are no abrupt diameter changes and no joint mismatches. This promotes increased flow and reduces back pressure. The size and configuration of the Magnaflow muffler that I use plus the long resonator does one of the better jobs of quieting the exhaust compared to these other systems that use smaller diameter cans in the axle back portion.

I don't have any back to back testing with my system versus any of the above but the results that George, Neo, Zyg and others have had do suggest that there are gains to be had with the system. BTW, one of my 2-1/2" exhausts with a 2-3/4" tip is currently supporting a 230+whp B20VTEC street car.

I should have a video of the ITR used in the header test this past Dec with my header and cat back so you guys can hear it. However, it was taken during a dyno run so it's inside a building.

Oh, one last thing, when we removed the 2" bottleneck in a Tanabe RM B pipe on an ITR with a Toda header and Car Sound cat the customer picked up 4whp in VTEC.

SMSP - Who has an optional 5" tip that comes with a chrome grill, chrome wheel lips, chrome door edge guards and chrome surround for the windshield, back and side glass at no charge. This makes the car look just like your father's old 1979 Buick.


[Modified by SMSP, 8:41 AM 6/4/2002]

Neo

hehehehehehe... LOVE the sarcasm, Dave!

hybridreams

When will it be available? I want!

Great info

DutchITR1689

SMSP - If the JDM header has an 65mm OD flange (63mm ID) and the 2.5" cats are also 63mm ID, why don't you make a fully 65 mm OD exhaust?

SurferX

Very informative Dave, thanks for all the great info.

People need to stop thinking of bolt-ons as a single part making a certain amount of power. It is an exhaust SYSTEM consisting of header/cat/b-pipe/muffer. If all those are sized and built properly you bet it's going to overpower the mass market garbage out there.

TsunamiZC

i'm loving my apex-i N1 exhaust sys. , sounds nice..looks good ...even for a big tip...but are you guys even looking at that smsp exhaust..that is some quailty bends and welds...it dont matter if the tip is 3' ...thats some great crafstmanship...if i ever decided to ditch the ditch my apex-i , i know what i would get...probably just wit a nicer tip

ZygSpeed

Thanks for the pics of my exhaust , and all the good info.
Hopefully I'll make it down to Rosen's or somewhere, next weekend.

Dentist's appointment in Albany NY thursday @3:30 (just a day trip).
113K miles here I come!

SMSP

Not all of the JDM collectors are 63mm ID. But anyway, I have to work with what's available. Mufflers and resonators here, in the states, come in 2", 2-1/4", 3" and 4" as standard. 65mm is 2-9/16" and the next size of tubing that is readily available in mandrel bends is 2-5/8". Cats also come in 2", 2-1/4", 2-1/2" and 3". The key to making any system work is smooth large bends, no sudden ID changes and where youare going smaller in tube size you should make it a tapered changed and gradual.


Here's the clip to the video/audio of my ITR header, test pipe and cat back system (the exact one that's on zyg's car) from the header test. Please remember that it was recorded in the shop and I believe that faint whining noise is actually the Mustang dyno.

http://vertigo.weirdness.net/~wwang/...er-exhaust.mpg

Thanks to Warren for posting it.


[Modified by SMSP, 10:26 AM 6/4/2002]

Anderson

good stuff

Christian

Dave,
I have more or less finished building my car. Its a B20Vtec, 84.5mm/ 13:1 RW pistons, Portflow head, Toda B's (can't find C's), Toda header (we'll talk about this), Edelbrock IM, AEM ems etc etc and I am now realizing that my Apexi N1 catback is pretty much shot. When I push the motor it sounds like the is muffler just wants to blow its inards out.
What size exhaust would you recommend for this setup? Would a 3" exhaust be total overkill?

Christian


[Modified by Christian, 10:05 AM 6/5/2002]

Junglist

my stocker put 157 on a dyno jet....did george do a baseline dyno?

edit...should of read futher before posting...sorry guys


[Modified by Junglist, 2:35 PM 6/4/2002]

SPOON EK9R

IMO, power gains depends on setup.... 14+whp for an exhaust for a NA engine setup over stock ? Maybe possible . No further comments..... doesn't make much sense to me.

People seem to be happy to this exhaust well, very good. I think the quality is just as good if I get a dynomax ultra flow with a bunch of U bends pipes cutted and put together myself or a regular muffler shop can do cuz I don't think it looked good at all.

FSTASNTZ

I will have to give props to Dave on his exhaust. I now am the proud owner of the one RStoR originally had. Nice fit, no rattles, looks good. In fact most think I have the stock exhaust. Which is fine with me.
On long trips, it does not drone like the last system I had, 2.5" pipe, no resonator, to a 2.5" Sebring straight thru muffler. That was loud, very loud, and would almost put you to sleep.
Next to a tuned header with a dump pipe, the SMS exhaust is probably one of, if not, the best exhaust you can buy for the investment...


Jason

SkyeC

I think it's funny how someone whined about it pointing down... Wonder if they'd care if it was pointing almost 90 degrees sideways like those "cool" n1 exhausts!

zijiejijeijrkjk

Ok, how much for the cat-back? Your site seems to be down Dave.

SMSP

Just curious, LS or B18C crank? Any dyno sheet? Well the B20VTEC with 230+ that I mentioned above is thru a 2-1/2" system. The header is one of my B20VTECs with a 2-3/4" collector. The system is set up to drop the center tunnel piping and then install a tuned length of 2-3/4" tubing for the track. For the street it uses a tapered 2-3/4" x 2-1/2" adapter to attach to the cat back system.

I have another customer who's getting ready to install the same header and I'll probably set him up with some 2-3/4" tubing into a 3" cat and then he'll run a custom 3" system or the Thermal. The 2 engines are very similar so it will be interesting to see the power differences.

But to answer your question, I wouldn't run anything less than 2-1/2" and I'd be a little concerned about opening a JDM sized collector up to 3" very quickly. I'd prefer to see the B pipe stepped to the 3" final size. This will prevent a sudden change in exhaust gas velocity. Not sure if I help you or not.

As for your Apexi muffler, do you know what kind of packing/sound deadening material they use? Honda318dx had a Greddy system on his Prelude which looked fine from the outside but sounded like everything inside of it was broken up. Magnaflow offers a lifetime warranty on their resonators and mufflers so I would expect you wouldn't run into that problem with them. They use a stainless steel packing material that weighs more than fiberglass but obviously lasts much longer.

sgT

The motor that Dave refers to:



Still needs a little work, but so far not bad.

SMSP

If we could get more air to it I think the top end would end up looking really nice.

Zeus

[QUOTE]SMSP - Who has an optional 5" tip that comes with a chrome grill, chrome wheel lips, chrome door edge guards and chrome surround for the windshield, back and side glass at no charge. This makes the car look just like your father's old 1979 Buick. [QUOTE]

Christian

Currently I am running a B18/B20 crank, although I am currently looking for a GSR block to be resleeved by Golden Eagle. I have no Dyno charts to post at this time but should have some in two weeks.

I had the same concerns about going from a 2.5" to 3" collector. I am trying to make it to Summit Point on June 22+23 so hopefully I can get down there a day early and pay you a visit.

Christian

vpc

on a side note if anyone cares for comparison...

the RS*R catback I had...had the ~2.35" ID at the b-pipe flange and then it shrank down to 2" at the resonator (which is one reason why the exhaust is so quiet) then grew back to ~2.35" exiting the resonator and stays that way with close to 90degree bends right before the axle. IMO the bends were the bottleneck on this exhaust because the ID *appeared* to be smaller than the ~2.35" the rest of the piping is... I think it was somewhere between 2" and 2.25" at the bends. Don't quote me on this though...

I'm currently getting ready to build a new exhaust with a setup similar to the SMSP. I'm basically using a 2.5" Magnaflow muff for my resonator, a 2.5" carsound kitty cat, and using Magnaflow bends. I'm still undecided on which muffler i'll be using but I'm heavily leaning towards the Twinloop because I'm a mugen-wh0re.


[Modified by vpc, 10:03 AM 6/8/2002]

canuck-mx6

What is the price for the SMSP exhaust? I really need to replace my Greddy EVO. I am tired of the sound, and I want something quiet.

sneakychaos

George... you really need some type of VTEC controller to lower your engagement point a few hundred RPMS and smooth out that powercurve... my god.