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-   -   90 Miata w/Greddy Kit I just Picked Up - Some Opinions Please (https://www.miataturbo.net/prefabbed-turbo-kits-3/90-miata-w-greddy-kit-i-just-picked-up-some-opinions-please-5194/)

samnavy 10-19-2006 11:03 AM

Somebody smarter than me should also post the limits of the MSD box... how much it will pull based on what parameters just for info.

Edit... never mind, I found it:
The MSD unit retards the timing 3° per pound of boost pressure with no more that 6° of retard being allowed. When no boost pressure is present, the ignition runs at the factory timing. These settings are fixed and cannot be adjusted. With that said, you can still run your Miata advanced to 14° of timing and when it boost it will retard back to a safe 8°. If knock is still present then set your back back a little. It's a little basic but it gets the job done.

Efini~FC3S 10-19-2006 11:07 AM


Originally Posted by samnavy (Post 50900)
The MSD unit retards the timing 3° per pound of boost pressure with no more that 6° of retard being allowed. When no boost pressure is present, the ignition runs at the factory timing. These settings are fixed and cannot be adjusted. With that said, you can still run your Miata advanced to 14° of timing and when it boost it will retard back to a safe 8°. If knock is still present then set your back back a little. It's a little basic but it gets the job done.

That doesn't make any sense, that means at 2psi of boost it's already pulling the most timing it can. It sounds kind of fishy I thought it was more like 1:1 but I'm not positive. Where'd you get that info?

Braineack 10-19-2006 11:21 AM

No it doesn't start pulling untill 4psi. The Bipes ACU was originally a mod for this unit to allow for more timing and adjustabitily controls. He ended up just making a unit to replace it all together.

expensivehobby22 10-19-2006 12:00 PM

So, the Bipes ACU is the way to go from what I've been reading?

Braineack 10-19-2006 12:58 PM

I wouldn't bother ripping it jsut to replace it with a Bipes. it works and you can still advance your timing to 14° and be at 8° at 6psi.

Ben 10-19-2006 01:23 PM

Sounds like you're really on top of it. Once you get your i/c piping improved, you'll flow so muh better than you will make the same amount of power at less boost.

If you have the blue injectors, I would adjust the boost controller to 5 or 6 psi until you get to the dyno. The walbro 255 doesn't flow well at higher pressures, even if it is the designated hp model. It might still be borderline at 8 psi with the tan colored 1.8 injectors and the 255. I can't get 8 psi out of my stock 1.6 injectors and my fuel pump flows at high pressures much better than yours. You may also want to open up the vortec fpr and measure the disk size, which will let you know what your rise is. Or get a fuel pressure gauge on there to see what that 255 does to your idle pressure.

I'm also running the msd sebring unit. It's fine, and you could always add an rpm trigger to it for almost no cost (I haven't). The bipes is better because it's adjustable and dynamic, but if you're going to replace it, I'd go ahead step up to a more capable piggyback such as emanage, which will allow you to run bigger injectors and really dial in your fueling and timing.

What's funny is my car looks ok in person and like hot ass in photos. Weird eh?



Originally Posted by expensivehobby22 (Post 50831)
Wow guys, thanks for all the thoughts and advice.

I'll check on the injectors when I get back in town. I'll also inquire with the pre-previous owner who actually did all the mods about the vortech.

The MSD is hiding down by the passenger side shock tower. Fits there rather nicely actually, although it doesn't seem to actually be fastened to anything...yet.

As for the IC plumbing, I'm not happy with it at all. I made it a little better than it was when I picked it up, but I've actually already downloaded a bunch of pics from this forum even before the suggestion.

Thanks again for the advice. A little confused though, samnavy says the car should be fine at 8, and even 10psi (assuming everything is functioning correctly) and ben is advising a bit more caution. Are you assuming somethings been missed in the buildup of this car ben, or are you just advising that I should do an in-depth dive into where the car actually is before being comfortable with it?

I like to do things correctly, so I tend to err on the side of caution myself.

Will post more pics when I get back in town as well. The car photographs well. It's a bit rougher in person.


cheesecow1 10-19-2006 07:39 PM

Give a look at the crank on it and see if ya got the shakes, like mine woot!:bigtu:

expensivehobby22 10-19-2006 08:11 PM

Thanks Ben. Same as this car, much nicer in pics :)

Talked to the previous owner. It's got the stock injectors, but he wasn't sure about the disc size in the vortec.

So, from what you guys are saying, I should definitely bring it back down to 6psi right?

So, what do I need to upgrade to run 8psi, or even 10?

Looked at the crank pulley, seems good. Apparently, the pre-previous owner pulled the pulley off when he did the greddy kit. It was fine, and then he reinstalled with a new key and loctite.

Man, can't wait to get home and actually drive this car again...haven't driven it since the test drive.

turbopezz 10-19-2006 08:39 PM

diddnt read anything but it looks......:bigtu:

StankCheeze 10-20-2006 01:31 AM

Get RID of that shock tower brace.

LunaticDriver 10-20-2006 02:22 AM

wire that AC fan to the Rad fan so they both go on... super cooling for the cost of 20 minutes of your time two connectors and some solider

samnavy 10-20-2006 09:08 AM


Originally Posted by StankCheeze (Post 51048)
Get RID of that shock tower brace.

Agreed, the brace will stiffen up the front end to the point that you'll push like a big dog. On the street it'll feel a little tighter and you'll think you've got more control... but it'll actually lower the handling limits.

I have yet to see a skidpad comparison of with or without a brace, but it was worth a full second to me on a 50sec autocross course.

Braineack 10-20-2006 09:08 AM


Originally Posted by StankCheeze (Post 51048)
Get RID of that shock tower brace.

why? We have coilovers and the brace barely does anything. Mainly just helps with cowl shake.

Braineack 10-20-2006 09:22 AM


Originally Posted by expensivehobby22 (Post 50982)
Talked to the previous owner. It's got the stock injectors, but he wasn't sure about the disc size in the vortec.

So, from what you guys are saying, I should definitely bring it back down to 6psi right?

Stock injectors limit your power levels.

If you have the original disc in the vortech you are trying to push 140psi of fuel into the rail. ([12 x 8] + 48). Something the pump cannot do.

Depending on the the pump, your maxing out at 120psi (Hp) or 80psi (Standard).

At 80psi those injectors are good for about 155BHP or 130rwhp (4-5psi).

At 120psi those injectors are good for about 190BHP or 160rwhp (5-6psi).

A 8psi GReddied miata should be putting down around 180rwhp. Chances are you are running lean past 5.5k. Not to mention adding a lot of fuel pressure in the rail. Most suggest no more than 100psi.

That being said, 240cc injectors (1.8L) are good for around 210BHP or 175rwhp with 110psi in the rail. You can acheive 110psi with the vortech with 8psi of boost by use of a 8:1 ratio disc. ([8 x 8] + 48). Closer in lines to where you power levels should be.

The best way to figure out what's going on is a trip to the dyno with a wideband hooked up. Or running one yourself (worth the $200 in gold).

At least throwing a fuel pressure guage on there and reading the levels in boost gives you a better understanding of how much fuel you are providing and limited to.

Listen for ping in boost too...that's the engine killer.

magnamx-5 10-20-2006 10:23 AM

Water methanol injection and some1.8 injectors will put you at 10+ psi easily, you could even relax the settings on the msd as well and run more timing there to make some real power. with WI 200 whp is possible on th e1.6's it helps effeciency that much get in on the group buy or do some reseaerch and find a product you like. the simple ones are quite effective though. nice car man. :)

expensivehobby22 10-21-2006 03:51 PM

Thanks again for the info. I'll have to follow up more when I get back home. Was considering getting a wideband for the RX-7 anyway so now might be the time to pick it up.

Ben 10-21-2006 04:07 PM

The msd sebring timing controller is not adjustable in anyway. Possibly you could restrict the signal tube to delay pulling timing, but there is no adjustment possible. That's why the bipes is superior.



Originally Posted by magnamx-5 (Post 51092)
Water methanol injection and some1.8 injectors will put you at 10+ psi easily, you could even relax the settings on the msd as well and run more timing there to make some real power. with WI 200 whp is possible on th e1.6's it helps effeciency that much get in on the group buy or do some reseaerch and find a product you like. the simple ones are quite effective though. nice car man. :)


expensivehobby22 10-21-2006 04:19 PM

So where do I get 1.8l injectors? Sounds like I should throw those in if nothing else. What about different discs for the vortec?

magnamx-5 10-21-2006 04:20 PM

ebay classifieds if i do well with my 430's i might sell my set

Braineack 10-21-2006 06:08 PM


Originally Posted by expensivehobby22 (Post 51301)
Thanks again for the info. I'll have to follow up more when I get back home. Was considering getting a wideband for the RX-7 anyway so now might be the time to pick it up.


buy the LM-1 and keep it portable to switch between the two.


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