Fuji Header

[Mx5-4me]

I'm in the middle of prepping my car for an FFS kit .. the next step i'm taking is installing an exhaust from the header on back. I still haven't decided if i want to go with a coldside or a hotside .. do you have any idea if the Fuji header will work with your Hotside kit ???


http://www.fuji-racing.com/fujiracing_086.htm

[dazooom]

That's a nice looking header! Looking at the picture though, it looks like runners 3 and 4 are too tall for a hotside, but, Tom will reply when he see's your question. I've never seen a Fugi header installed, and pictures can be deceiving. The Jackson Racing header fit's the hotsides, as far as I know. I have one on my 01. I had a RB header, and #4 runner was too tall, for the hotside sc. If you look at the picture of a current, RB header for your car, you will see that #4 runner looks similiar in height to the #3 and #4 runners on the Fugi. ( I have heard of at least one person that got his RB header to fit with a hotside sc though).

[Mx5-4me]

That's a nice looking header! Looking at the picture though, it looks like runners 3 and 4 are too tall for a hotside, but, Tom will reply when he see's your question. I've never seen a Fugi header installed, and pictures can be deceiving. The Jackson Racing header fit's the hotsides, as far as I know. I have one on my 01. I had a RB header, and #4 runner was too tall, for the hotside sc. If you look at the picture of a current, RB header for your car, you will see that #4 runner looks similiar in height to the #3 and #4 runners on the Fugi. ( I have heard of at least one person that got his RB header to fit with a hotside sc though).

Thanks for the input .. i also have fired off the same question about a hotside to Fujil .. I really like the header i'm hoping it has 2.5" collector. I'll give as much info as i can once i hear back from them ..

My plan is to use this header with a Good-win-racing mid pipe and a roadster 3 axle back .. if the header has the 2.5 collector it should give me 2.5" all the way back ..

I'm hoping this will work with the hot side but i don't want to be the one on the "Bleeding edge" of finding out ... hehe

[Tom @ Fast Forward]

There is not a lot of room under the hotside. I think you may have a tolerance problem with the 3/4 runners from the picture. However, it is difficult to see if they actually raise up or just out? It could be one of those questions that can't be answered until it is tried?

[Mx5-4me]

There is not a lot of room under the hotside. I think you may have a tolerance problem with the 3/4 runners from the picture. However, it is difficult to see if they actually raise up or just out? It could be one of those questions that can't be answered until it is tried?

Thanks Tom,

I should be calling you in August for a kit .. Hopefully by then i'll have this question answered..

If you could squeeze 250 WHP out of a coldside. I think i'd know which kit to get. Still with all the good reviews i keep hearing it's likely to be the one i purchase.. i'm only a little concerned later i wouldn't be happy with the projected 220 WHP limit which is why i'm thinking about the hotside ..

[Tom @ Fast Forward]

The problem with exceeding 220WHP is that the engine internals, transmission, diff, axles, etc all start stressing more than they can handle reliably. Then you start rebuilding those things and, like the $7000 engine I built, the last 30 WHP gets real expensive. For me, the quest for 250 just never justified the cost.

My main market is the 200WHP crowd that wants 200 reliably and clean, smooth power. Above 200 engine life decreases. At 250, I think it is even more dramatic. Just my humble opinion.

[Mx5-4me]

The problem with exceeding 220WHP is that the engine internals, transmission, diff, axles, etc all start stressing more than they can handle reliably. Then you start rebuilding those things and, like the $7000 engine I built, the last 30 WHP gets real expensive. For me, the quest for 250 just never justified the cost.

My main market is the 200WHP crowd that wants 200 reliably and clean, smooth power. Above 200 engine life decreases. At 250, I think it is even more dramatic. Just my humble opinion.

and a valued opinion it is again thank for the input ..


I submitted an E-mail to FujiRacing about the header..

Here is what i sent them:

I'm interested in purchasing one of your headers for my 99 Miata. Can you give me some specs on the construction of it??

What size are the primaries ??
What is the size of the collector ??
Does it have an O2 Bung ??
Any idea of this will work with a Hotside MP62 Supercharger Kit if so which one(s) ?

Thanks,
Mike

This is what i got back:

Hi Mike-I do not believe that our header will clear a SC. The header is on the market and some customers are happy with them except that it does touch the steering shaft. We are working on making them so that it doesn't come in contact with the steering shaft.

Regards,

Jimmy
FujiRacing


They left a few of the answers out so i resubmitted the following questions. basiclly the same with some modification on the O2 bung question.

thanks for the reply .. can you answer some of the other questions I asked ?? I haven't purchased a Supercharger kit yet finding the right header will help me decide which kit for me to purchase ..

What size are the primaries ??
What is the size of the collector ??
Does it have the stock location of the O2 Bungs ??

[chuckerants]

If you haven't driven a 200HP+ Miata, you really should take a drive in one. With 207HP, though I'm concerned about drive train longevity if I go for more power, my immediate concern is getting stickier tires. lol

[Mx5-4me]

If you haven't driven a 200HP+ Miata, you really should take a drive in one. With 207HP, though I'm concerned about drive train longevity if I go for more power, my immediate concern is getting stickier tires. lol

I plan on starting in that range. i suppose i'm more concerned about an upgrade path ..

My plan is to go with a 15x8 Wheel with a 225/45/15 Tire .. that should help with traction .. also trying to source the 3.63 gear set for the diff ..

I'm kind of surprised there aren't more header options out there with a 2.5" collector and the proper sized primaries (1 3/4 to 1 7/8).

I've read about a Gibb header but it sounds like those aren't being made any more ..

To me it doesn't make much sense having a 2.5" mid pipe and axle back with out the header to support it ..

just my opinion ..

[chuckerants]

How about an 01+ OEM header?

[Mx5-4me]

How about an 01+ OEM header?

yes i have been reading about the advantages of the newer OEM header..

but isn't it still a 2" collector ??

[Curiousgb]

I don't know what your goals are but if noise is an issue then a 2.5" midpipe might be too loud. I have a 2.5" FM mid with Borla sport duals. With the SC it is really loud at WOT. Cruising with the top up isn't much fun either.

[Mx5-4me]

I don't know what your goals are but if noise is an issue then a 2.5" midpipe might be too loud. I have a 2.5" FM mid with Borla sport duals. With the SC it is really loud at WOT. Cruising with the top up isn't much fun either.

That's a VERY good point ..

here is the FM Turbo mid pipe

http://www.flyinmiata.com/Store/images/06-58200.jpg


Here is the Good-Win-Racing Mid Pipe

http://www.good-win-racing.com/miata/images/items/RoadsterSportMidpipe.jpg

they look to be different products .. i wonder what the difference in sound is ..

[Digitac]

Well, I recently installed the Good-Win-Racing Midpipe because I needed a new Cat. Prior to that my entire exhaust was stock, so I still have the stock header and stock muffler (am I the only one??). I haven't heard the FM, so I can't compare or comment there.

I'm still not sure if it's the combination of that midpipe and the stock muffler or what, but when it's cold (my car only gives me trouble when it's cold) it has that annoying raspy/rattling exhaust sound that some of the Honda guys seem so fond of (no offense to the Honda guys here). Thankfully it goes away after a couple minutes once some heat gets in (which makes me wonder if it's an exhaust leak at the muffler).

Other than that, it's not significantly louder. At WOT it's definitely more noticeable, at cruise it's close to stock according to my ears.

I'll probably drop in the Roadstersport 3 it was designed for in an effort to get a deeper sound, and maybe eliminate the cold start sound.

Over all, I don't regret the purchase, mostly because it was half the price of an OEM Cat!

Digitac

[Mx5-4me]

Well, I recently installed the Good-Win-Racing Midpipe because I needed a new Cat. Prior to that my entire exhaust was stock, so I still have the stock header and stock muffler (am I the only one??). I haven't heard the FM, so I can't compare or comment there.

I'm still not sure if it's the combination of that midpipe and the stock muffler or what, but when it's cold (my car only gives me trouble when it's cold) it has that annoying raspy/rattling exhaust sound that some of the Honda guys seem so fond of (no offense to the Honda guys here). Thankfully it goes away after a couple minutes once some heat gets in (which makes me wonder if it's an exhaust leak at the muffler).

Other than that, it's not significantly louder. At WOT it's definitely more noticeable, at cruise it's close to stock according to my ears.

I'll probably drop in the Roadstersport 3 it was designed for in an effort to get a deeper sound, and maybe eliminate the cold start sound.

Over all, I don't regret the purchase, mostly because it was half the price of an OEM Cat!

Digitac

Thanks for the input..

I started a thread on m.net in the Power Mod section hopefully I can find someone that has some real world experience with both products that can shed some light on this.

My thinking was that the 2.5 FM midpipe was intended for use with a Turbo. Turbos quiet an exhaust system down considerably and i'm thinking FM took that in to consideration when building the midpipe. Good-Win-Racing only has one midpipe that i'm guessing they built with the idea of using it on SC/Turbo/NA set ups .. Thus building it with more sound reduction in mind .. Again this is just my line of thinking. I don't have any "proof" of this ..

[Tom @ Fast Forward]

I run the RB header. I ordered the midpipe from Goodwin but it was drop shipped from RB so I would guess it is theirs. I had the Raodster Sport III sounded great but the drone on the highway gave me a headache so I put the stock muffler back on and love it. Basically quiet until you put your foot to the floor. We proved that the stock muffler cost as close to zero WHP as zero can get. So that is where it will stay.

[Mx5-4me]

I run the RB header. I ordered the midpipe from Goodwin but it was drop shipped from RB so I would guess it is theirs. I had the Raodster Sport III sounded great but the drone on the highway gave me a headache so I put the stock muffler back on and love it. Basically quiet until you put your foot to the floor. We proved that the stock muffler cost as close to zero WHP as zero can get. So that is where it will stay.

Hmm .. very interesting.. so maybe i shouldn't worry so much about anything post header .. just wait for them to go bad before replacing ..

[Tom @ Fast Forward]

Only thing I found post header worth worrying about after a gazillion dyno runs is the cat. Things might be different at 300WHP but not at 200WHP. Not sure about the header on pre-99 cars but the 99+ showed that. What we saw was that a turbo needs an exhaust matched to the turbo so that it can spin up as fast as possible (speed of the air flow) but not restrict the air flow at high RPMs. A comparatively small header pre-turbo and a large exhaust post header. Key word there is comparatively. I don't , by any stretch of the imagination, mean a "small" header but rather one to give maximum speed to the air entering the header. You almost need a different exhaust for evey different turbo. For a stock Miata, it is similar. A tuned exhaust helps scavenge the cylinder and helps induce intake flow. But a SC is so forgiving that all it needs is for the exhaust to get out of the way. On the 05, for example, we found no difference between the stock exhaust and an open header.

[Mx5-4me]

Only thing I found post header worth worrying about after a gazillion dyno runs is the cat. Things might be different at 300WHP but not at 200WHP. Not sure about the header on pre-99 cars but the 99+ showed that. What we saw was that a turbo needs an exhaust matched to the turbo so that it can spin up as fast as possible (speed of the air flow) but not restrict the air flow at high RPMs. A comparatively small header pre-turbo and a large exhaust post header. Key word there is comparatively. I don't , by any stretch of the imagination, mean a "small" header but rather one to give maximum speed to the air entering the header. You almost need a different exhaust for evey different turbo. For a stock Miata, it is similar. A tuned exhaust helps scavenge the cylinder and helps induce intake flow. But a SC is so forgiving that all it needs is for the exhaust to get out of the way. On the 05, for example, we found no difference between the stock exhaust and an open header.

WOW .. I had no idea .. Live and Learn ..

i guess with my first phase staying at or around the 200WHP mark i don't really need to worry so much about exhaust then ..

Maybe a header if i go hotside so i don't have to remove it to install one later..

Thanks Tom ..

[Kyp J]

This is just a question as I am definitely not an expert on dyno graphs:

Does the header (Fuji in this case) have something to do with max RPM attainable? The graph in the example at the beggining of the thread appears to be different only in the RPM reached. Maybe even a bit less for the header in torque at the high end except for the longer run up.

[Mx5-4me]

This is just a question as I am definitely not an expert on dyno graphs:

Does the header (Fuji in this case) have something to do with max RPM attainable? The graph in the example at the beggining of the thread appears to be different only in the RPM reached. Maybe even a bit less for the header in torque at the high end except for the longer run up.

I believe the explanation was one header stopped making power (it could still rev farther just no more HP) at a lower RPM than the other..

[Tom @ Fast Forward]

Remember, those dynos were on a stock engine. Headers have a greater effect on a stock engine than a supercharged engine. On a stock engine, a properly designed header can add 10 WHP easy. On a supercharged engine, it probably will make zero difference.

[Mx5-4me]

here is the latest update from FujiRacing..

Mike-Primaries are 1.5" and the collector I do not share the specs but it is larger than mostly what is out there and that is why the top end does good. It does have a O2 bung.

Regards,

Jimmy
FujiRacing

I'm Not real happy with his approach to not share this info.

I guess he figures no one will messure it before they install. yeah right..