Jeff20B

iTrader: (13)

Madatrix sells the flywheel by itself. They recently expanded to three options. 17.1pounds, 12.1pounds and 7.75pounds. VW Adapter Kit

I purchased my flywheel back when they only had two options. I thought I was getting the heavier one, but I weighed it and came up with 12 pounds!

I was actually really happy but a little confused. As you can see my old one was 16.5 pounds and I recall it felt heavy on my R5 rotating assembly. I also tested it on an S4 NA assembly and it felt right.

The weights work out as:
R5 11.5+11.5+4+16.5=43.5 pounds (felt too heavy)
S4 10+10+4+16.5=40.5 pounds (felt right)

Now with the new 12.1 pound flywheel:
R5 11.5+11.5+4+12=39 pounds!! (should feel perfect!)

This should also feel just about right. I can hardly "weight" to drive it!

Also I think Mazdatrix slightly screwed up on my order. First they were out of stock so it took a LONG time to ship. The guy there said it's because KEP had to make the flywheel. So I was wondering if it would have been better to order directly from KEP, but I've done that before and it wasn't as easy as ordering from Mazdatrix, so I was ok with waiting an additional week or two.

Then they sent the 12.1 pound flywheel, not the heavy one. At the time, they only sold two options: the heavy or "standard" one and they also sold a 9 pound lightened one. Well, I ordered the cheaper standard one. They sent the 12.1 at the cost of the "standard" one. See the website. The three prices are 212, 247 and 357. So I got the one that should have cost 247 for only 212!

And I'm glad I did because a 40 pound rotating assembly feels perfect in a 1st gen and felt perfect in the baja for the brief time I was testing the S4 NA on the heavy flywheel. The heavier R5 assembly on the medium weight flywheel should mimic the somewhat lighter S4 assembly and heavier flywheel combo.

So do yourself a favor and get the 12.1 pound flywheel even though it is a little more expensive. You'll love it!

rotorbugg

Clever...

Jeff20B

iTrader: (13)

Thanks. Any progress on yours? I made some on mine today. I figured out a long primary exhaust that'll be around 80 inches if I go with my first idea.

If it turns out that it won't work, I'll need to shorten it just a bit to maybe around 60 inches or so. That is still enough. Basically anything over 50 inches is good when measured from exhaust port to the crotch of the collector. You also have to collect to 2.5". Anything smaller kills power from 4k up. Anything bigger makes far more noise and hurts low end power (which your baja needs).

The other option is a turbo but this "project" has far too many "bugs" in it to worry about big power at this time. Gotta get it up and running as an NA first.

I think I'll throw a carb on it tomorrow and get started on a fuel system or something. Hmm, maybe radiator first. Then exhaust. Then fuel system. Then wiring. Should I follow in that order? Or begin with something else? Like a stereo? Nah. The rotors make the music.

silverfdturbo6port

iTrader: (26)

Im still interested in the clutch you offered me to go with my adapter plate. Builds looking good btw

rotorbugg

Hey Jeff, glad to see you are still at it. I know what you mean about the turbo... I've got a TD05H lying around from a friends eclipse and it's tempting since I already have a Haltech, but like you said - gotta get it running as a NA first. There is enough to do just to pull off the swap. How about some fresh pics for inspiration? I've been working on mine lately and I'll try to post an update.

About exhaust manifolds, I test fitted a modified manifold on my car today using a solid trans mount and it came very close to fitting without the spacers. (It would easily clear with one) I could make it fit by clearancing the trans mount, or shrinking the neck on the manifold more. (See attached photo)

The moral of the story is that you could cut the neck off of the exhaust manifold and weld pipe to it using the right alloy wire/rods.

Jeff20B

iTrader: (13)

Looks like I can't do the long primary after all. Too much radiated exhaust heat would make its way into the oil pan. Hmm, maybe I should just go for the S5 turbo and a boost prepped Nikki?

If I jostle some things around here, I could get my buddy's S5 turbo and at least get it in there before winter. All I need is a muffler and a u-bend in 2.5". Thinking a Magnaflow 5x8 offset/offset in 18" with a 2.5" core.

Oh and I'm seeing if I can double what the stock bug engine made at stock RPMs. It did 50 to 55hp at only 4200 RPM. Can an NA rotary do that much (110 doubled) at only 4200? I think a stock 6 port setup or a turbo could do it. But my current 76 Cosmo core that I used here was rated at only 110HP at 6000! It would be like 70HP or so at 4200. Not to mention the reduced torque compared to the bug engine's peak at 2600rpm! No wonder this thing was so slow back when I first tested a rotary in it. I just figured a long primary would take care of the slowness, but there is no room for a proper one, you know? So looks like I have to go turbo in this thing.

So if a stock S5 turbo can give me my 110HP at 4200 (plus all the torque I'd ever need, presumably), anything else it can do above that is gravy. Or biscuits or whatever the saying is.

Thoughts?

Jeff20B

iTrader: (13)

Ah screw it I'm going NA with the racing nikki! Easy starts rain or shine. Big NA power. Less likely to break stuff. Untested cooling system. Gotta work the bugs out of the conversion etc etc etc.

Narfle

iTrader: (16)

What about a gearing advantage for all those extra rotary revs?

Jeff20B

iTrader: (13)

It has a 3 rib so It should have good gears.

Narfle

iTrader: (16)

I mean wouldn't you want a shorter final drive since the 13b turns like 3000rpm's more than the old vw engine. Then you'd have a gearing advantage to make up for lost torque with the NA setup.

Jeff20B

iTrader: (13)

Bus tranny + big tires gives it basically stock bug gears, however I think the 3 rib is the better choice for a basic upgrade because it supposedly has the 5.something ratio where as the 5 rib has a 4.86 ratio and while slightly stronger due to more case ribs, isn't as good of a choice in stock form. I don't really want to spend big bucks on a beefed trans at this point, so I'll just go with the 3 rib. I also might try out a 12A first to work the bugs out of the conversion. Then swap to a 13B when I'm sure the exrtra torque won't break stuff.

Jeff20B

iTrader: (13)

This is the muffler. It's really big. Should be enough if going turbo.

Still might not be enough if NA so I might need one more smaller one next to it.

Jeff20B

iTrader: (13)

So I got the 5x11 and set it on some blocks of wood. Turns out there is like no room for a second smaller muffler. So I can either A) use an exhaust manifold similar to rotorbugg with a u-bend outlet feeding into the muffler, and hope for the best, or go with my other idea B) the S5 turbo and a blow through Nikki.

It fits!

rotorbugg

Hey Jeff,

I like that muffler, especially cause it's 2.5" in/out. The muffler that I had been thinking about getting was from a 2002-2003 Saturn Vue (pic below) but it's only 2" in/out and though made for a 3L V6, might be a tad restrictive. I bet it would be quiet though.

I'm not looking forward to shoehorning a hot exhaust into the street bug but since you have a baja, what about running the exhaust up over the engine? (Don't let me talk you out of the turbo though!)

Jeff20B

iTrader: (13)

Then you'll like this muffler even more; I test ran it on a fresh rebuild sitting on a creeper. This engine had stock 12A exhaust ports and a stock exhaust manifold with a small section of connecting pipe which ended where the cat would have been. This pipe is only 2" diameter. I grabbed a 2.25" piece to mate it into the 2.5" muffler.

Honestly the noise was not bad at all, for a single muffler. This setup is actually just about right for the street if you want to hear your exhaust, which most rotary owners do (my personal preference is for slightly less noise but you might be fine with it on a full body bug, if you can get a 22" shell to work in there).

Only thing I worry about is the longevity of a magnaflow this close to a rotary. At the end of the system in a regular car, they're fine, but this close to the engine can kill it in like six months or less. My GLC is experiencing this right now on a 5x8 used as a presilencer. I'm toying with some ideas to go long primary in it, but that's for another thread.

We know how strong and hot the exhaust is on these. Hence the desire to go turbo to tame the exhaust in both noise and muffler destroyingness. I just need to test run this turbo in something else first to get the basics of boost.

In the mean time, speaking of presilencers for the GLC, I had some materials left over to throw a 12" one together for the baja. It is only 2", but if I also throw the GLC's 5x8 in there, I'll have an ok NA setup for the baja that I don't need to worry about for 6 months of testing (still needs a proper shake down to check coolant temps and all that). The 5x8 is 2.5" but that's ok. This is just a test system that needs to be quiet enough for the street. I'd rather protect the brand new 5x11 with the turbo, plus it's so huge that no other mufflers can be used, other than the stock compact S5 turbo, which I only needed to space out away from the engine about 1/2" to use a stock hitachi intake manifold. There is actually a tiny air gap between the compressor housing and the front secondary runner. Good thing the exhaust housing is plenty far fromt he other runner.

By the way, that muffler picture above has changed from when I posted it. MF must have updated their look or something. I don't like it. This here is more or less what mine looks like, from their old stock photo (look somewhat computer generated, but whatever, you get the idea).

KansasCityREPU

iTrader: (9)

I know this won't work with a turbo, but for a non-turbo it might work well. Turn it so it faces the rear.

spokanerxdude

iTrader: (4)

You'd wake up the people next door with that thing for sure.

Jeff20B

iTrader: (13)

That would be a very lousy choice for a street driven baja, I'm sad to say. First the flanges are for a twin dizzy engine so wouldn't help anybody within the last 20 years, unless they're a die-hard 10A or early 12A lover. Second they're way too small denoting either thinwall (not a good idea on any rotary in any case) or just plain too small in diameter to flow worth anything at the high RPM the super short collectedness would suggest.

An over all terrible design. But then I prefer long primaries so what do I know?

My latest concern is about street driven quiet exhaust. Not the racing only thing pictured above. It still seems to me a long primary is out of the question. As much as I would have liked to build one in the baja to enjoy the good low end torque without the need for a turbo, there just isn't enough room to justify the incredible time and effort required to build one for this type of chassis. But if I did go through with it, then what would I be left with? A lot of pipe that is heavy and hot and a lot of time wasted on medium power at best. It could still end up being super loud too, as long primaries delay the mixing of both rotors which ups the noise levels a lot. It seems the turbo option is always the better choice from every angle I look at.

Still another NA option is a small tubular exhaust manifold based on a stock cast iron manifold design. It consists of one header flange, two 2" thickwall pipes of about 3 inches length, a 3" thickwall pipe with two 2" holes drilled at 13cm for a 13B spacing, then an end cap on one side and a u-bend outlet on the other which curves around into the 5x11 muffler. Only good for low to mid power levels at best. But a heck of a lot simpler to build! Oh and possibly just as quiet (or loud!) as the overly complicated long primary, but half the weight!

The complete turbo setup pictured above is currently out for testing. Based on the findings in the test vehicle, it will determine whether it finds its way back in the baja. Fingers crossed everything works out.

Which option are you rooting for?

turbo = high power option
long primary = medium power option
simple tubular NA exhaust manifold = low power option

doghouse

iTrader: (1)

I'm doing a similar conversion in my beetle

Jeff20B

iTrader: (13)

Nice. Do you have a build thread?

As for my stuff, I've come up with a forth 4 option. I have a dead S5 turbo kicking around. I'll take off the CHRA and use just the exhaust housing as my manifold. This puts the muffler where it needs to be and avoids all the problems turbos have. Eventually I'll get the CHRA fixed/replaced but for now this makes the most sense.

I can't find the right picture, but it should look something like this.


The stock turbo exhaust manifold is probably less efficient than a stock NA exhaust manifold. That's ok. After discovering I can't use the racing Nikki here anyway, due to the small NA exhaust and small intake ports, I'll just throw a stock carb on it and get it up and running to work out the bugs. I'll still set up the fuel system with an MSD pump and a mallory FPR because there's no reason not to. Then it's compatible with NA and boost.

Now gotta work out the details of which intake manifold to throw on. Then which air cleaner assembly... I'm thinking the better of the two NO manifolds and the RB spun aluminum air cleaner because water can't get in if there is a piece of rubber up there under the wing nut.

doghouse

iTrader: (1)

My thread is at wheelsjamaica.com I will send you the link

Jeff20B

iTrader: (13)

The new tall style radiator is in with fans installed. The new fuel system is in. The rad and fuel pump just need to be wired up. Saving that one for a rainy day.

I'm going to remove the 24V starting mod because it wears the flywheel and starter teeth down really fast. Ever seen how fine those teeth are? Instead I'll repurpose the components to make a parallel 12V dual battery (like jumper cables) connected through the fender mounted solenoid whenever the ignition switch is in the cranking position. Makes a lot of sense seeing how VW starters are kinda slow and they drag the battery from 12V down to 9 or 10 volts. With two batteries there with twice the amps available, the drag down in voltage will be less allowing the starter to crank faster and will keep the teeth and even the starter's inards healthy for a long time. So more wiring for a rainy day!

I just looked up VW clutch discs and pressure plates and found this website explaining how to find the differences and what you can expect from various components. Building a VW clutch torque measuring tool- Hot VWs Magazine

My setup has a new flywheel, so proper step height or "depth" as they call it, with no grooves or anything, is what I have. The current pressure plate is a Sachs but I don't recall whether it's a heavy duty at 145 ft lbs or the stocker at 90 ft lbs.

My clutch disc is currently the copperhead disc.

According to their webpage, and assuming I have the stock Sachs p-plate, I can expect 130 ft lbs of clamping power from the additional 40 ft lbs the copperhead provides. Will it be enough? I'm actually more worried about the stock 3 rib trans and stock beetle CVs than a slipping clutch.

I had plans to go turbo in this, and I have basically all the parts needed, but I worry about the VW components as they were rated by those wacky Germans at max power, not the RMS power (sorry to borrow a term from audiophiles) like Mazda tends to do. I'm affraid that the turbo will push my torque levels to beyond what those components can handle. I would rather have the pressure plate and disc be what "gives" and not the trans or CVs. I also like the easier pedal effort of the stock pressure plate.

I do have a Kennedy Stage 1 and a Bug Pack pro disc if needed. Also a stock duty Daikin (Exedy) VW disc seen earlier in this thread. I know Exedy makes great products for Mazdas so it's an option...

As for the engine, it's been upgraded to an essentially stock 76 Cosmo engine with upgraded nitrided side plates and slightly opened up exhaust ports. Stock intake porting to retain maximum low end torque at the expense of high RPM power. Don't need high RPM here (plus the VW trannies don't like it anyway). I'm talking about stock 76-85 12A port timing at 40 degrees. Only the exhaust port closing timing was delayed by 2mm (ported up) until the bevel was gone, then recreated in the Judge Ito style. These ports already opened at T2 spec so no need to open them sooner. I would have prefered GSL-SE exhaust ports for obvious reasons, but the stock 76 Cosmo engine was complete and already broken in, more or less except for some oil seals I had to swap in due to high amounts of wear on the originals due to the non nitrided R5 side plates the engine originally came with. Now a fresh set of low step wear nitrided Y irons are installed.

One thing I'd like to point out about the 76 Cosmo engine is the power it was rated for:
110HP at 6000
120 ft lbs at 4000

This is not impressive by most standards, but compare it with the stock 1500 single port the beetle came stock with:
50HP at 4200
77 ft lbs at 2600

Uh oh. The VW is a torque monster at low RPM. How do I mimic it on a rotary? With a turbo! But then I worry about the drivetrain etc. A stock S5 T2 is like what 205HP at 6000 or something? The torque I'm sure is impressive for whatever RPM it is.

And then you check out turbo bugs and bajas on youtube and they always turn out great because the stock 1500 and 1600 engines are extremely weak by today's standards. You practically need a turbo just to keep up with traffic anymore. All those grey 200+HP heavy grocery getters these days. Grrr.

But that's where I reach an impass. I've done some testing of an S5 turbo in the "brown car" as I call it (GSL-SE with a blow through Nikki) and it has enough power now to break them loose in 3rd gear on dry road. I don't need that kind of power in the baja. Heck I've heard of baja guys breaking trannies just on the stock 1600, and even more on the 1776 and bigger engines. Actually, a 1776 is not a bad upgrade because they can be made to provide 106torque and 100HP. Not bad, but then there is a cost. I have plenty of rotary parts to do that kind of power cheaply. But then where does the HP and torque kick in? At low mid or high RPM? With a VW it's obviously low to mid, unless it's built more high strung, which is even bigger bucks. With a stock ported rotary it's mid to high, and a ported rotary is basically high only. A turbo changes that back to low, mid or high, or all three if done right, and I've seriously considered it for awhile now. But only now with my latest testing, which has revealed some excellent power in a chassis that can actually handle it (the brown car), do I seriously question whether to continue down this path any further for the baja, or rethink the project to be the best NA setup I can possibly build.

I think this website about clutches has helped me make my decision, and that is to go NA for now. I figure that the stock 76 Cosmo engine's torque will go up to at least 130 ft lbs, and the power is also probably going to be 130 as well wit the upgrades I have planned. The torque should kick in at a lower RPM as well, or least it will reach 120 at a lower rpm now, making for a more rewarding driving experience with large baja tires. Hopefully even the magical 77 ft lbs at hopefully 2600. But how?

•DLIDFIS, which is better than points and worth 5HP to maybe 15HP everywhere.
•Keeping the 76 Cosmo reverse runner manifold which has the best (longest) primary runners of any stock manifold for the best low end possible. Hey, the Cosmo was a big heavy car! It's been channeled and studded for a Nikki install.
•Stock Y and Cosmo intake port timing of 40 degrees for the best low RPM and still ok for midrange power. I expect it to peak by 6500 which is fine for the VW drivetrain.
•After careful hogging out of five Nikkis in a row along with boost prepping earlier this year, I discovered one that doesn't like boost due to always flooding out after every time it sees boost, however its low end in vacuum is amazing. Easily the nicest driving Nikki I've ever driven. Better than EFI in a lot of ways. It starts right up rain or shine, the idle circuit is strong and healthy, the accel pump is adjusted perfect, the transition circuit is perfect, the primary circuit turned out perfect (not an easy task when you mod a carb to be 24.7mm up from a stock 20mm venturi and retain this kind of driveability which is actually better than stock! This is bigger than Yaw and Sterling by the way). I only hope it will still run like this once tuned for NA.
•The RB spun aluminum air filter with a rubber seal across the top (so rain water won't get in). If you look earlier in this thread you'll see a foam filter setup which aren't the best for flow. The spun aluminum RB should flow well enough with a K&N, right?
•The flywheel is a stock steel VW 12 pounder modded by KEP which should be just right for the Cosmo R5 heavy rotors. Didn't want too light or too heavy which are also available. You'd think a baja wants heavy, but nope. When I previously tested this car with an S4 NA engine, its lighter rotors really helped the gross old cast iron 16 pound flywheel to get up and move. Well since R5 rotors are heavier, I chose a flywheel which mimics that total rotating weight, which should drive almost exactly like an RB light steel flywheel at 13lbs. This should be good! You can look up rotor weights in Mazdatrix' FAQ.
•Oh and one last thing before I forget, the hogged out primary venturis, if done right, provide MORE low end torque, not less, than a stock Nikki. How can bigger with less velocity make more power? Compare this with the stock 76 Cosmo Hitachi at 22mm primaries where other J-spec later hitachis only had 20mm. The fact it's a 13B could also have something to do with it. Anyway my hogged Nikki has 24.7 on average which was about as far as my tools will cut by hand, so that's where I usually stop. I did one all the way out to 24.9 average, a couple others at 24.7 and one at 24.5. I can tell you the 24.5 carb feels the weakest out of the bunch, until you open the secondaries which wanted to make them break loose in 1st gear on dry road back when I was doing NA testing in the brown car. Only the Racing Nikki could do that with its massively hogged out venturis primary and secondary (26mm and 31mm respectively). The 24.5 carb has only had its primaries done. Pretty impressive! But it too hates boost so only two out of the five carbs I hogged out actually like boost. Of course the fuel lines in the test vehicle are backwards according to Mallory's intructions where you want 5/16" send and 3/8" return, not the other way around like mine it setup up which is probably leading to flooding on the more sensitive carbs.
•The baja's fuel system was built from the ground up according to Mallory's intructions along with a Mallory 4309 fpr and an MSD fuel pump. All EFI rated fuel hose because I don't trust carb hose after several have dried up and cracked over time. Apparently EFI hose doesn't go bad.

So as you can see, I have the foundation to go turbo, but NA sounds like the better choice, for now. I just hope the NA exhaust will be quiet enough for the street. That's one nice thing about turbos. They act as their own mufflers. They're the only muffler that adds power.

Anyone care to add their 2 cents?

Jeff20B

iTrader: (13)

Small update. I've decided to stick with the NO manifold in the baja for several reasons.

•it's already in there
•it retains backwards compatability with the S5 turbo
•it means I don't have to pull the reverse runner out of the REPU, which, arguably, is actually a better place for it, again due to the low end torque it should provide. The only downside is it's more difficult to get a carb to idle right on it due to its size, and the reduced velocity through its larger runners can make the low end feel a bit mushy compared to the crisp little NO manifold. We'll see.

Back in the day I tested the racing Nikki on the NO manifold and the reverse runner when they were on the Icy engine in the blue car. I liked the NO better for the crisp low end response. High end seemed fine too, so there you have it. NO it is.

NO is a casting letter/number combo like Y or R5 or 3B. It's just old school stuff.

Jeff20B

iTrader: (13)

Thought you guys might want to check out the lastest progress.


And the charge pipe routing.

Jeff20B

iTrader: (13)

So I recently found out the bus trans has a drivetrain loss of around 20%. This is due to the hypoid gears they use which are less efficient but stronger than what's found in a bug trans. This means if I'm aiming for 100HP to the wheels, I'd need 120 to 130 HP at the flywheel with my bus trans.

I was told 100 at the wheels is plenty. You can do a lot with just 100HP, they say. I don't doubt it, and I could have a peak HP at that level with a stock ported R5 13B pretty easily, but they were also assuming an air cooled VW engine. Those things make great low RPM torque. The HP is just the way they measure power over there for some reason. I thought you measure... torque?

Problem is the rotary doesn't make that kind of torque at the same RPM. I need a way to get the low end grunt of a 2332 without the cost. So stock S5 turbo?

I worked out some numbers. See if you can follow my math.
150hp x .2 = 30
150 - 30 = 120hp

160hp x .2 = 32
160 - 32 = 128hp

162.5hp x .2 = 32.5
162.5 -32.5 = 130hp

For example, if the turbo makes a max of 150HP, with a 20% drivetrain loss, I'll have 120HP at the wheels. Likewise if I get 162.5HP at the flywheel, I'll have 130HP at the rear wheels.

I think 150 to 160 HP is pretty realistic, actually, considering the stock S5 turbo made 200HP in an FC at stock boost levels and stock T2 spec intake and exhaust ports with a top mount IC. My baja engine has smaller ports and most likely won't have an intercooler. So I'm going from 200HP under factory intended conditions down to 150 to 160. Then factoring in a 20% drivetrain loss I'll get about 120 to 130HP at the wheels. I think that's realistic. And that's being generous. I think the actual numbers will be lower still. Like 100 to 110HP (but plenty of low end torque!). Thoughts?