1994 1.8 Turbo - Critique & Advice?
 

Hey Guys!

I recently picked this 1.8 Turbo car up as a base for a track car I want to build.

On getting it back from picking it up, it definitely needs some work and a good map. It's not quite the full package I thought it was, but I think it will be a good base to work on. There are hesitations on wide open throttle and at part throttle. Also the turbo seems to spool, (noise wise) but nothing happens speed wise until about 4200rpm (2k rpm after you hear it spin up). The wheels and roof are terrible, and will be being changed ASAP!

I also found the shitty Ebay manifold to be cracked and the exhaust is blowing all over the place. Other than that, I am happy.

Hopefully I will be replacing the cracked manifold with a BEGI, FM or Artech manifold. Anyone have any advice on this? I realize with any of those options this will mean I will need to change the downpipe too as the turbo orientation will be different, but I have also seen this Ebay cracked manifold replacement from Artech....

http://www.artechfabrication.com/Tac...eplacement.php

What are your thoughts on manifolds guys?

The turbo is definitely a Garrett T25... that's all I know 100% and that it has an FSE power boost valve.

I am in talks with Dimitris to provide me with a MS2 to take care of the management side of things. I am decided on MS for sure after reading countless good reports on both here and MX5nutz.

In terms of checking the car over and working out what to order next, what would you guys be looking at? I really am a newbie when it comes to turbos!

Any help you guys could give me would be hugely appreciated!

https://www.miataturbo.net/attachmen...ine=1364310811

https://www.miataturbo.net/attachmen...ine=1364310811

https://www.miataturbo.net/attachmen...ine=1364310811

https://www.miataturbo.net/attachmen...ine=1364310811

Im not sure but for a track car I would use a turbo that spool a little bit faster to avoid lag.. maybe an expert could argue on that.

MS is the right way to go! im looking for one at the moment!

And your car looks pretty good!! i like the Tan soft top :)

T25 is as small as you ever want to get on a Miata engine.

Cracked manifold will hurt spool quite a bit.

You'd have to look at shipping, but if you can find one it might be cheaper to buy an exact copy of the manifold you have on Ebay and send it to artech, might be cheaper than shipping it from the UK. Otherwise just pull the old one off and send it to Abe.

However you might be better off going with a new downpipe also, since I wouldn't trust the ebay one and it probably flows like crap too. Exhaust is another thing to look at, from the state of this car already I am going to assume that it is probably running the stock exhaust. You're gonna want to trade that for a 3" straight through.

Ducting the rad and a coolant reroute will be necessary cooling mods for turbo + track.

Also lose the hideous wheels.

If you are serious about tracking it, go inconel studs with resbond (assuming this is still the current practice of the track guys). There is a thread on it somewhere here.

Also go quality manifold/downpipe. I think artech is a good idea. I like my BEGI cast piece as well. Just get something quality if you want it to last on the track. Nothing wrong with a t25, especially for stock motor.

You've got some kind of ems or something there, as that MAF is not what comes stock on the car. Whatever you have, ditch it for a megasquirt with IAT sensor.

Wheels are teh gay, you knew this.

What suspension is it running? That may need addressing for a track car. Car is obviously lowered, but with what struts/springs?

Nice radiator at least, that's good.

Adam I feel you pain. I recently changed out my cracked s4 manifold / downpipe elbow.
https://www.miataturbo.net/attachmen...ine=1364322880

What kind of EMS is on the car?

Who cares what was on there before, it was failaids. MAF (pictured) = Stock ECU.

Eh, I would think a bigger (laggier) turbo would stay cooler. He can use the transmission to stay in boost.

The wheels have been ditched already! REALLY not my thing!

Suspension wise I will be getting coilovers. I have these sorted already, and know what I am doing re Miata suspension. Its on Tein springs with Bilstein shocks at the moment. Its just the actual turbo setup I have no real idea on!

EMS is a piggyback Dastek ECU but I will be ordering a Megasquirt.

What I really need to know is what to do with the actual setup. I agree with thenudge as well reagarding the downpipe probably being super pony Ebay shiz. It does have an aftermarket exhaust though which I would guess is 2". I will probably run with this for a while saving to upgrade it. I just want to get the actual turbo setup rock solid at the moment before anything else is upgraded.

I think I prefer the turbo being higher in the bay too so I think Ill look at getting it side mounted and getting a new downpipe as well as a priority, along with the Megasquirt.

What kind of BHP do you think I would be looking at from this T25 setup once running well on the 1.8?

Thanks for all your input guys!

Sturovo, what manifold is that you replaced the cracked one with? Is it a custom made jobbie?

Adam, I made that manifold. It is relatively easy to make but you would probably need to change the downpipe using that type. I am currently making a reversible S4 replacement that should fit in the same spot as your ebay manifold. Again easy to fab if you get the flanges cut somewhere.
https://www.miataturbo.net/attachmen...ine=1364414706

should take 8 weld els and a couple of flanges :fael:

https://www.miataturbo.net/attachmen...ine=1364414706
http://i578.photobucket.com/albums/s...ps33a45059.jpg

Hey Sturovo!

That is some good work! I have been looking over on the MX5Nutz UK forum and there are a few guys on there that have also made there own manifolds, both of which have been running them for years now with no problems and are both pushing upwards of 200bhp, one of them 253bhp!

One of these guys has offered to make me a manifold from mild steel just like his, so I think this is what I will do as importing a BEGI or a FM to the UK is going to be very expensive, and if these homemade manifolds are lasting 4+ years pushing 250bhp that is good enough for me.

The thing I need to look at now is weather I want to sidemount or topmount the turbo, or leave it as it is like the S4 manifold. I am inclined to change it for a sidemount if the Rover 220 Garrett I have will mount in this way... What do you guys think?

Ad

Double post! :S

hi fella im just getting the parts together to do my turbo build and im sorry to say it i have the same manifold lol
do you have a list of the items the car was turbo'd with?
so far ive got
t25
down pipe
manifold
fpr
mbc
both oil lines
oilfilter sandwich
boost gauge

looking into the intercooler at the min but i cannot afford to go ecu yet so thats why im asking lol

So It Begins!! - Forced Induction & N/A Power Mods - MX5Nutz Forum



little editing to say yey first post in 2 years

I dont sorry mate!

I litterally have only just started going through what is actually on the car! I think I should have just bought a standard one and a seperate kit! :brain:

What kind of power do you think I will be making from a 1.8 with a T25 guys? I'm debating weather I should look for a T28....

I'd like 225bhp touch.

You can make 225 on a t25. Read some build threads, asthey will answer more questions you will surely have in the ffuture.

I'll have a read through some now.

The TD04 is also an option as the manifold will be changed and the TD04 is really cheap and available here in the uk.