Eaton m62 supercharger
 

Hello
I recently purchased a supercharged 99 miata. it has a eaton m62 supercharger installed with intercooler. It's running at 5psi boost and the previous owner told me, in order to increase that, I need to replace the pulley. I've been trying to do some research on this and am finding different answers everywhere. I'm fine with the car the way it is now, but just curious as how I'd go about increasing the boost to 9-10 psi.

Thanks

Which kit is it? BRP, Moss? Hot side, Cold side? I bought pulleys for a previous MP62 setup from Gary at http://trackdogracing.com/TDR-SC-PUL.aspx. Get in touch and they'll help you decide which ones you need.

Either one will point you in the right direction.

BRP, and I'm pretty sure hot side (not 100% sure)

It's BRP and hot side, although I'm not 100% sure about the hot side. How do I check?

Hotside means it's on the exhaust (right) side of the engine, looking from the front. Coldside means it's on the intake (left) side.

https://1drv.ms/i/s!ArGcOIBZVETn0nQ9uAWq8LQ2IND1

it's definitely hotside then. So all I have to do is get a ~115-125mm pulley and I should be good? No other parts required? No messing around with the computer chip card thing in the car? As you can tell Im new to cars and boosting and whatnot

In for part out....

Thanks for being so helpful thirdgen. I'm sure people think you're funny

If you have a powercard you may not have the injectors necessary to increase your boost or horsepower from the current level. You should determine how much headroom you have prior to proceeding.

First and foremost, you have to answer a few questions:

• What size is your current crank pulley?
• Do you have stock injectors with a fifth injector setup?
• How many powercards do you have?
• Do you have a wideband O2 sensor - or, "AFR gauge" in your car?
• What octane gas are you using?
• Have you ever checked to see if your intake system has any "boost leaks"?

There are more questions, but these are what comes to mind right away.

Now..
Yes, if you have a 5th injector setup and three powercards, you "can" run up to 10 12 psi boost.

And, that would require a few things:

• A bigger capacity fuel pump
• Re-tuning the engine (It's possible, but you HAVE TO find the right person to do that - fueling adjustment gets tricky)
• Colder spark plugs (BKR 7 series)
• WIDEBAND O2 SENSOR AND GAUGE (Don't even think about skipping this)
• Stronger clutch (Choices too numerous to list here)
• Biggered, largered exhaust
• Improvements for the cooling system
• Et cetera...

There is a huge difference between 5 psi and 10 psi boost in terms of engine management, fuel supply, cooling, power transmission and handling.
Power is really nice, but it does come at a cost.

If you just buy a bigger pulley and bolt that on, let me know.
I can also help you with a partout thread.

Thirdgen and godless commie are trying to tell you in the politest way possible, that if you just bolt on a bigger pulley, chances are very good that your engine will go boom.

You need to add fuel (at a controlled rate) or your engine runs lean, detonates and very quickly destroys itself.

Yes, rleete is right. I am in no way trying to be a dick, and you habe to understand the humor on this site. In fact, if you would like help from somebody as sophisticated as myself, I would be more than happy to help you.
Pretty much what we're saying is it sounds simple enough to just put a big pulley on and run 4 more pounds of boost than you're running, but that 4 more pounds of boost can do lots of damage. Especially because I'm pretty sure you have a power card or something which does not control timing at all, and it's a poor way to control fuel as well.
Please tell us more details about your setup. What kind of intercooler do you have? What size exhaust do you have? What are you using for a wideband?

Oh, and it's an MP62, btw.

Thanks for the replies. I asked help for something else before on the regular miata forum and encountered dicks, so I just assumed that's how forums are. But anyways, I will get all that info tomorrowish, or try to. Might have to ask previous owner about some of these things.

Mp62 on 5 psi might be maxing out stock injectors, or close.

I hope the car is a fun learning experience.

The people on this site are some of the most knowledgeable around for boosting miatas. They can be jerks sometimes though. :P

Once we know exactly what you have we can point you in the right direction to start researching how to upgrade though. Modifying cars at this level requires lots of research and learning or you risk a blown up engine.

Yea, of course. I'm not in any rush, in fact I don't even know if I want to do it as the car feels great now. But eventually people get bored with the amount of power available. I'm gonna take my time with this, do it right. Gonna infiltrate the local miata bro network and find some knowledgeable people

Just curious, What exactly is Murtaxa?
Is it Murtaza ot Murteza?

I highly recommend against this. The average Miata bros are complete morons. Stick around here, read a bunch, save a LOT of money, keep reading build threads. In about a year you will be ready to take on your dreams of moar boost.

PS, stay far away from anyone who uses tems like "slap on this" or " Re-flash that".

or ever mentions the words "drift" or "stance"

When did you start moonlighting as a French hooker?

5psi on a MP62 kit, even off the shelf, is a little on the low side. You're probably running the default 95mm. For each larger larger crank pulley of 5mm, you're generally getting one extra psi of boost. Plan accordingly. 10 psi is roughly 200 rwhp on this kit, very repeatable results. You can still get different size pulleys from FastForwardSuperchargers.com.

Figure out what kind of fueling solution is being used by taking a pic of the stock ECU and whatever aftermarket card is patched in.

Sorry for late responses. Wanted to find out info on miata but life had other plans and I havent had time to do much besides new tires.

Murtaza. I wasn't feeling very creative with my gamertag, I wanted to get my name as the tag, but had to settle for the closest sounding one.
Yea, after talking to a few of them I realized they're all about the turbos and think superchargers are stupid. But the guy who changed my tires at firestone used to own a "ubercharged" (as he described it) miata, and he offered to do cheap work on the side. Plus he made my brake and steering wheel noises disappear so I trust him lol
But dat stance tho
I need to just open the hood and measure the pulley size. The weird thing is, the previous owner had a dyno chart that showed 185whp, so with reaching 10 psi, I should see over 200whp?

Also, I wanted to ask you guys for recommendations for a good replacement supercharger belt? The firestone mechanic told me it looks worn out. I should've just asked him, but was in a rush

thrash her till she pops!
its a secondary belt

This one will do?

https://www.flyinmiata.com/na8-nb-ac...ac-and-ps.html

Find the number on the existing belt. Buy a Gates equivalent - auto parts store should be able to cross match numbers.

Lots of factors determine size. What tensioner, 4 or 6 rib, what size pulleys, etc.
Go here: Gates Racing Performance Micro-V® Belts if you need to know how to measure for a new belt.

Take the belt off, go to parts store, lay it on the counter and profit.

I found these numbers on the belt, 1413ac and 76135s32. Dumb question, but which pulleys do i need to measure? If anyone could point to them (if visible in this pic) or where they should be behind the radiator. The one on the right measured 70mm

Or that, makes more sense.

That number (1413ac) checks out as an 8 rib belt.
I'd take it to the parts store.

yea I think you found the same link I did. Maybe the previous owner cut his own belt or something. But I'll be taking it to autozone once I figure out how to remove it. Gon be fun.

Take a 3/8 ratchet (or 3/8 breaker bar), stick it in the square hole in the tensioner, rotate clockwise (or, you can stand over the drivers side fender and pull towards yourself) and slip the belt off one pulley.

It's easier than it sounds.

Pic from google images, and not a Miata...
Should give an idea, anyway..

https://cimg4.ibsrv.net/gimg/www.mia...59da2a63e4.jpg

So I got the car dyno'd last week, and it showed that the AFR was all over the place, and always above 12. And the boost was actually between 6-7 psi So the guy recommended I get a tune. And he suggested i go with haltech for ECU, since thats what he works on the most.

If I'm gonna spend the mula on a ECU and tune, might as well get new pulleys and injectors.

What do you guys recommend for ECU, and injectors. And what size pulleys would get me to 10-12 psi. Thanks in advance

Megasquirt 3 for ECU. For pulleys... does an EFR count as a pulley? :)

--Ian

For ECU, if you are going to pay someone else to tune it, you get what they are good with.

Injectors should be easy to find what we all recommend here.

For pullies, you have to go by the pressure ratio for a supercharger. So at 6-7psi, you are at a pressure ratio of 1.44, and you want to get to a pressure ratio of 1.82. So you need to increase the speed of the supercharger by 1.82/1.44 percent. Which comes out to 126%. So take your current pulley size and divide by 1.26.

This may not be exact, but will get you in the ballpark.

Yea that's what I was thinking, but haltech is so expensive. And i believe it has the stock pulley setup of 95/65mm but i will double check.

Your AFR should be above 12 if you are only reaching 6-7 psi.

And if you get a Megasquirt and a wideband you don't need a tuner.

Haltech is cheaper than rebuilding your motor a time or five because it's not running well. If you want to tune the car yourself, get whatever ecu you'd like. If you'd like to utilize your tuner's services, get what they like.

https://cimg0.ibsrv.net/gimg/www.mia...ca3be45f20.jpg
https://cimg5.ibsrv.net/gimg/www.mia...f66f9d9e63.jpg
Yea I dont think I'll be able to tune it myself. I'll have to play the waiting game , periodically check online and see if a good deal pops up. I'm thinking I need the haltech 1000 ecu? If anyone wants to chime in, feel free. I'm gonna order a 125 mm 6 rib pulley. I checked previous injector threads, and I'm still confused. If anyone can just post a link to the best bang for buck injectors for 10-12 psi, would be appreciated. What else do I need to look into?

I have 550cc ev14 injectors in for last 4 years, no problems and ecu shows the % duty is below 60. So loads of headroom.

seriously consider a megasquirt so you can tune the car yourself. You can also log runs to see if your belt is slipping.

If your Haltech will drive low impedance, peak and hold injectors (some of them will, IIRC), then your best bang for the buck is to buy some old RC550s. No, they're not as fancy as the modern ev14s, but with low impedance drivers they idle fine and they're cheap. Megasquirts don't have low impedance drivers, so nobody wants the RCs any more. :)

(I have a set of those for sale, PM me if you want more info).

--Ian