More SC pulley info

I just got a digital non contact tach to verify the rpm of my supercharger..it cost $25 from this joint.

see the chart below to see the math that I have come up with to stay below the mfg max rpm for the blower. I am not sure if one can calculate boost level linearly or not, I suspect not thus I have not done it. If you have thoughts on this please let me know.

In the chart you can see the blue cell, which is my current state of 12psi at 7500rpm which currently yeilds 212rwhp with a very rich (read SAFE) tune. I am going to change to the 2.8" pulley, which I already have, next year. I just want to enjoy what I have right now

Pulley Swap

Just made a video on how to swap the pulley on the supercharger

Water Meth Injection

I installed Water injection a while back and thought I'd show some pics of how I did it.

the nozzle mount

From cosworth

From cosworth

From cosworth

the tank bracket

From cosworth

From cosworth

installed!

From cosworth

From cosworth

the pump bracket

From MX5 general

From MX5 general

From MX5 general

From MX5 general

From The Blue Meany

From The Blue Meany

If you are looking to buy a pulley for your NC here is where I get them

Boost Boost, so nice I said it twice.

I just cant figure out what is going on with my boost...my 2.8" pulley went from making 16-17psi to making 20psi..so I went back to the stock 3.3" pulley which for everyone else (and for me prior to the engine being rebuilt) was making 8-9psi....now I'm seeing 12-13..what gives? bad boost gauge?

I borrowed a buddies spare boost gauge and decided to record the happenings to review while not driving..here it is.

injectors

Well I decided to part with the MagnaVolt which was boosting the fuel pressure, or at least attempting to stabilize it. It was unable to increase the pressure beyond what the ECU was calling for (59psi) but it was able to stabilize the pressure which thus would keep the 390 injectors pumping out enough fuel,barely.

I didn't like the complexity of having to try and tune around this apparatus and it fueling increase only under boost, it just added another damn thing to try and consider when tweaking the system...so avoir MagnaVolt.

I got some custom 550 injectors from the Fuel Injector Connection. they are Ford long body injectors apparently from the Cobra, and punched out to 550 then flow matched. they cost roughly $250.

These injectors seem to be perfectly compatible with the car. Idle is good I have not noted any issues.

...still working on getting the tune right, thanks to Mike Mann for the help in that area.

Dash Dyno car specs

In order to use the Dash Dyno you have to have some car specs..here are mine
frontal area 19.37 sqft
drag coefficient .34
tire height 23.6"
gear ratio 4.10:1
car weight 2550lbs (w driver and full tank)

I can see it now

Decided to mount my Dash Dyno rather than have the suction cup mount forever. The Dash Dyno has become a somewhat permanent fixture in the car while going through the tuning adventure as it has knock alarms and is able to display the OE wide-band O2 sensor among other things. It will likely be in the car through the summer until I am confident that I have a tune that won't destroy this new engine. My main concern and focus was that I wanted to be able to quickly remove the DD and cable to pop in another car if needed (2 phillips screws) and I wanted the DD pointed directly at me, as the alarm LEDs are recessed a bit and if not pointed at you they can be missed when flashing. Mission accomplished.

As I make metal products for a living I've decided to somewhat promote some of the low demand items I make on this blog as I come up w them. No heavy sell, just if you want one like mine it's available.

This mount is CNC cut from Aluminum and is texture coated with low sheen black. I think it blends reasonably well. It's held on w 3M VHB tape which sticks awesome and is actually rather easy to remove w the right technique (floss and a rubbing finger). If you'd like one of these mounts It's $19.50 shipped.

From MX5 general

From MX5 general

From MX5 general

More boost...

Time to add more boost to my built motor so here is what I know:

Stock pulley:
3.3" diameter
0.64" keyed shaft (not press fit)
0.4" offset
6 rib
nut torque spec: 45 ft-lbs
Magnuson part number: 58-90-06-033

Stock Cosworth belt:
Gates Micro V-AT K061040= 6rib 104"

The supercharger is rated at 16000 rpm so I cant exceed that.
I decided to go with the cheapest pulley I could find for testing purposes as I could not find any formula that would determine boost output. I went with the smallest readily available pulley which wouldn't overspin the blower. The charts to the side are from Magnusons web site for this blower.










I bought a 2.8" pulley from PulleyBoys.com Install wasn't too bad, there is only one bolt to remove (do this before you loosen belt tension or use an impact wrench)then i used a cheap pulley puller ($5) from AutoZone to pull the pulley off. They say that a puller is not needed but as it was my crappy puller barely was strong enough to get it off, so don't believe the hype. I put the new pulley on with some anti-sieze lube and torqued the nut.

The ne w smaller pulley required a new shorter belt so I got a Gates Micro V-AT 061031= 6rib 103.625"OD. This is for sure the shortest belt one could go with for this app as it was a tight install but that is what I was looking for.

so here is the pudding...14psi! at a little under 15k rpm at redline. NICE!

idle time

So my car would not idle for the first 50 miles or so, upon startup it would but if you revved it it would simply die. That made for some tricky intersection work as I found I needed a 3rd foot to keep the car running.

Now with 200 or so miles on it is has really stabilized and seems fine. I'm hoping for another beautiful day tommorrow so I can put a hundred or so miles on the car. I want to have at least 500 miles on it before Pat at Sniper/Delta gets his hands on it next Monday the 15th.

Engine Break-in

Cosworth tips for break in:

Adam,

Here are some general break in guidelines.

Let us know how it turns out.



Before Starting

During the break-in process, we recommend using a high quality API SJ or newer mineral 20W-50 engine

oil. We also recommend using a genuine Mazda oil filter. Do NOT use a synthetic or synthetic blend

during the break-in process. We also strongly recommend priming the engine’s oil system before starting.

To do this, make sure there is no fuel or spark by disconnecting either the ECU or by removing the

appropriate fuses. Then crank the engine for 30 seconds or until there is oil pressure registering on an oil

pressure gauge.

Engine Break-in

Upon initial start-up hold the engine at 2000rpm for 10-15 minutes for proper camshaft break-in. If the

engine will be broken in by driving the car, then drive the vehicle at various loads, speeds, and throttle

positions while keeping engine speeds below 4000 rpm for approximately 1000 miles or 1660 kilometers.

The longer the engine is broken in, the better your results will be.

The engine should be calibrated to achieve an air fuel ratio rich enough for
the type of fuel you are using. Consult with a professional tuner if you are unsure of what air fuel ratio

you should be running.

More fried brakes anyone?

Putting my car together, going through everything and found some more toasted brakes from the last track outting...I think I am done with these Maruha pads now.

From blown engine

From blown engine

Header install tip

If you have changed the headers on an NC or are planning on doing so here is a little tip that will save you 30mins and a pocketful of change from going in the cuss can.

The heat shield on the NC MX-5 is a real pain to remove and install. there are fastening points, one nut on the firewall (easy) and 2 bolts running longitudinally on the car. Them middle bolt isn't so bad, but the front one is a bastard as it is right above the alternator.

Here is my tip, slot the bolts with a Dremel or similar and just unscrew them from the top. Once you have the shield out, notch the mounting holes so that you can partially install the bolts then slide the shield in or out without having to remove the bolts totally in the future. Once the shield is in place just screw the bolts tight from the top, then snug them from the underside.

From blown engine

From blown engine

From blown engine

It's alive!

I got the car up and running last night! It started really easily and I had no leaks, first time go!

Idle is a bit lumpy and lower in tone, presumeable from the lower compression ratio and Cosworth cams.

couple things left on the agenda:

-hook up the H2O/Meth injection.
-run a catch can for the crankcase vent, Cosworth says it can mess w the intercooler if it vents into the intake as the factory had it.

heading to Florida mid-March to get the car tuned by Delta.

a source for NC trim fasteners at a fair price!

http://www.pointe-products.com/itemclass/Mazda-Clips-Fasteners

check it out.

Got some custom mats as a Christmas gift from a friend. They really look great.

From cosworth

From cosworth

You can get them from http://www.blazecustoms.com/Home.html

Read this if you have an MX-5 w DSC

From MX5 general

Putting the engine back together I realized that I had to order some new gaskets (intake, exhaust, water pump) so I ordered them from mazdamotorsports development. Gosh I really like those guys. Super easy to talk to, they know cars and parts, they don't talk to you like you're an A-hole like the parts counter guys, AND you save money! What more can you ask for. I also had to order some front brake pads as I fried them at my last outing. The savings was huge. really cool.

The day has come

From correspondence with Cosworth last week:
In regards to your specific question about what modifications were done to the engine;
Good used engine block
Forged crank as supplied by you
Cosworth forged rods
Cosworth forged low comp piston
Cosworth rod bearings
New rear seal
balanced
Cosworth MX1 cams
Cosworth updated valve springs
Fresh valve job
New Mazda head gasket
Professional assembly

Your engine is done and will ship within the next two days with your used parts except for the engine block.

Yeah, it's gonna be bad!

The pistons have arrived!

I got an email from Cosworth today letting me know that the new lower compression ratio pistons are available. They also said that they will be assembling my motor and should have it done before mid-month. Nice!

here are the pics that they sent me of the new pistons, Almost too pretty to have splashing around in oil.

From The Blue Meany

From The Blue Meany