Help a newbie on his stututu journey
 

Hi,

So I have a few questions.
I've always wanted to build/own a turbo miata. Through a friend of mine i have the chance to buy a turbo 2000 nb miata for a pretty good price.
I know my way around a car but I am not that experienced in FI cars and building them.

The car has 118k miles (190k km) at the moment and has been turboed since 111k miles (180k km).
So it has ran around 7k miles (10k km) with a td05 16g turbo from a subaru forester.

The engine has been "fully" overhauled, and forged around 4k miles ago (7k km)

It has recently been fully taken apart again to take a look if everything was still working correctly, which the seller "ofcourse" said it was.

The build itselfs seems fine to me and there has been nothing wrong with it while it was on the car.

The car runs a safe 13 psi (0.9 bar) and has 230hp and 225nm of torque at the moment.
It has a 5 speed and a torsen lsd. I've already ridden in it and It doesn't make any weird noises to my knowledge. But I am still on the edge if I want to buy it or not. Because I do not want something that breaks on me every month if I perhaps drive it everyday.

Now my questions are:

1. what things do I have to look out for on such a build?

2. What things have to have been overhauled for the car to be safe for the mileage it has.

3. The mileage on the car isn't that low so do I have to keep something else in mind on the car?

4. And how reliable would this build be and what could be the potential cons and dangers of owning something like that if any?

I am sorry if this was a lot to answer but I hope some bright minds around here can help a fellow newbie with his stututu journey ;)

Welcome! Now, who built it? Any receipts of the motor being torn apart? Why is he selling it? Is it cheap shit or genuine parts? History and quality is what you're looking for. Buying someone else's project car can be a rocky road.

Mileage isn't really a big factor here. Lowish is nice, but you need to do a compression test to determine the health of the motor. Is it professionally tuned? A bad tune could significantly degrade the motor over 7k miles.

Where are you located? Another forum member might be able to check it out with you in exchange for a 6 pack:beer:

And for the record stututututu is not a good noise :) Read up on compressor surge and then buy a BOV!

Hey first of all thanks for the reply!

To answer your questions:
Who built it?
He build it himself, it isn't his first build. But it was one of his earlier build in the beginning.

Any receipts of the motor being torn apart?
He did the rebuild himself with his dad, a lot of pictures, so the rebuild was indeed there and not his first rebuild. But it is a bit of a gamble if he did it all correctly. I have to take his word on this one.

Why is he selling it?
He is selling it because the guy has 4 other cars, like a 500hp subie, 400hp stagea and a 700hp civic. So he doesn't use this one anymore and he finds it a shame to just let it sit there. That is why he is selling it for pretty cheap to me, priced to sell.

Is it cheap shit or genuine parts?
The turbo is a genuine td05 16g from a scrapped forester, and the exhaust manifold was a custom made manifold. For the rest of the build it all seemed pretty well balanced in terms of quality. But than again I am not an expert. If you have any tips in terms of general things to look out for it would be awesome!

Is it professionally tuned?
Yes the car is tuned by a professional tuner. In terms of the tune the car runs great. Only small hickups on a really cold start, but just apply a bit of throttle and it'll do just fine. after that the tune is very well balanced. Expected with an aftermarket ecu.

Where am I located?
Well, I live in the netherlands so I don't think many forum member could swing by and take a look, or it would take more than just a pack of beer.

I am going to look into a compression test, thanks for this tip. I hope this answers a bit of the uncertaintys and I hope you can give me a better pespective of the build if it would be a good buy.

Yeah I know the stututu indeed is bad, sounds cool but bov is the way to go

Again thanks for the reply!

All that sounds like the seller is pretty familiar with turbocharging cars, and the picture documentation is a good sign also. What ecu is it running? Is there a receipt/documentation from a reputable tuner?

All in all if it’s a really good deal then to me it sounds pretty good. Maybe plan to dump an extra thousand in if something goes wrong. Even though the turbo is the main attraction, don’t forget about the regular miata things…..rocker rust is a NO!

Good luck!

Okay that is pretty good to hear

The miata is runnig a megaquirt 3 pro so no issues there and there is documentation of the tuner, like a dyno chart and other thigs that show it has been tuned by a professional. So no worries in that department.

The miata itself seems pretty good, no rust just a few dents and scratches and such in de front fenders and on the door. But nothing that cant be replaced/repainted in the long run.

I'll still look into a compression test to know if the engine is in good shape or not, but thank you for the help!!

Good! MS3Pro is a sign of a not-so-trash build. Some more things off the top of my mind: check for leaks and such around all the turbo line connections, look inside the oil fill cap and make sure there's not metal sparks, check brake pads, and ask about maintenance history. Just use your judgement and visually inspect everything that you can, and listen and feel for strange noises or issues. It seems to be a pretty solid build from what I'm reading. The results of the compression test would either seal the deal or break it for me.

To ‘fully take it apart again’ is a lot of work to do without having a reason. Most people don’t tear down an engine for a look without first having a concern they are investigating.

Your questions sound like mine before I bought my first turbocharged ‘Miata’ (Mx-5 where I am).

Be prepared to find the original builders mistakes and compromises, some of which will be costly to set right, and enjoy the learning curve.

Well "fully" is indeed a misleading term, my bad. But he took the top off and took a look inside to check for rubbing or any other things that may be wrong etc. But still I get the point you are making.

And mistakes are indeed inevitable if the build isn't done by a professional, that was also the reason why I asked for some general tips to watch for in such a build

that is alsk one thing I am certainly woried about, I am throwing myself right into the deep end of something I know little about. It could work out great, and even if shit breaks it will probably still be lots cheaper this way than to turbo my existing mx5. But when something breaks it will be one hella job to get that thing fixed up myself without having to break my head with info.

Yeah indeed, that is what I was thinking too. Seeing if the compression test is good is a break or deal. But can There really be that much wrong with compression if the engine starts and runs fine without hickup or loss of power?

Remember to focus on the comp test numbers being similar, rather than the absolute values. My engine ran and started great and had one cyl nearly 15-20% down on the others.

Check the little things like how they did wiring or any cutting, hose routing, etc. Those can be an indicator of the attention they pay to doing good work. Otherwise it sounds like a decent car based on what you've posted.

Some good pics would help us rate the car as well. Engine and otherwise

one question I have though is, what if compression isn't great like 20% difference. Would it be an extreme no go or could it be fixed and go trough with it?

I don't have that many pictures from specifically the engine up close but this would give you an idea of the car.

It has a few dents and imperfection all around the car but nothing that can't be fixed for a few bucks.
https://cimg8.ibsrv.net/gimg/www.mia...15fc1a28c5.jpg
https://cimg9.ibsrv.net/gimg/www.mia...30272f8012.jpg
https://cimg0.ibsrv.net/gimg/www.mia...99157719ae.jpg
https://cimg1.ibsrv.net/gimg/www.mia...a0707dd056.jpg
https://cimg2.ibsrv.net/gimg/www.mia...f113f051b5.jpg
https://cimg3.ibsrv.net/gimg/www.mia...b1d5cfc884.jpg

Wow, that is gorgeous! I really hope this works out for you :)

As far as the compression test goes, it's best to run one first!

When I bought my Miata I was mechanically inept. I brought it to a trusted third party to look over it for me before signing over the title. Even if it's just a performance shop nearby, a second set of eyes always helps. If it costs you a few bucks to learn there's a major hidden red flag, it's worth it. If it costs you a couple bucks to know that it's looks pretty damn sound, the peace of mind is worth it. Maybe not jiffy lube though (AKA not the run of the mill in and out service shops, get someone who genuinely cares about cars and will take a deeper look into it).
Seeing the underside is always good too, even if you can't get it on a lift throwing it on jackstands and crawling underneath is a good idea. Check for leaks while you're down there.

Can you make a picture of the exhaust manifold and turbo setup? I'm 80% sure this car was once from a friend and I made that turbo manifold. That car has some history.

OG builder
 

Hi, this is one of my ex-cars.

I’ve built the car originally from a stock wrecker nb to a boosted track-like setup.
It did run on a fully stock unopened engine when i had it.

as far as i know the next owner bent a rod due to unholy launch-control abuse..
which is why the engine has been rebuilt with stronger rods etc.

After the rebuild it has been running without issues, engine wise.

if you do choose to buy the car, ask the previous owner for my contact information as i do still fix any tuning issues on that car.
https://cimg0.ibsrv.net/gimg/www.mia...f2d1c3316.jpeg

That's crazy if that is the case, if the license plate indeed ends with "**-*f-bg" it is probably the car. The next owner indeed bent a rod but stated that he had put the turbo on himself or something along those lines.

but you still tune the car or something? Because it was tuned by "vpr tuning"

I don't have a picture of the manifold at the moment but if the license plate was "**-*f-bg", bent a rod and it kissed a pole in it's past it is the car you build the manifold for. It was one of the first and big concerns I had with the td05 setup he had because a custom manifold is almost a must.

Plate starts with a 5 aswell..
caterpillar did also indeed weld up the insanely thick walled manifold to prevent any possibility of cracking it..
another mate helped with the intercooler piping and exhaust..

I have installed the turbo, exhaust, intercooler setup, megasquirt ecu, done the wiring, tuned the car on the road, and finished the full tune at VPR’s dyno as the owner is a good contact.

the main limitations i ran into was the stock 1.8 clutch not wanting any more as of then. Had a max 260nm at the crank to prevent clutchslip.
i’ve added the dynosheet so you can definately see the torque limitation and how perfectly flat it is.

https://cimg0.ibsrv.net/gimg/www.mia...5fe92babe.jpeg
believe this is wastegate vs boostcurve..

yup, it is indeed the same car. The tune is indeed really well made, you felt how flat the curve was while driving the car.

The car seems to have an history. But the thing I am woried about is the reliability. And the risks with buying a build is that there can be parts that are neglected, and that wouldn't be a problem if you know exactly what parts and how to keep em healthy and such. But as the buyer I can't exactly know those things.

So do you perhaps have any things to keep in mind on the car, any problems that might occur over the long run and such. Because you probably know A LOT more about this specific car than I do.

I do know it has an oil leak which the seller says it is probably cause by the sandwhich plate by the oil filter.

as far is a am aware:
Do the normal maintenance.
change sparkplugs every oil change with grade 7 gapped to 0.8 mm
oil leak you’ll need to check. As it is at the sandwich plate dont wait for a failure, could cause low oil pressure.
clutch is strained at pretty much max torque it can kind of handle.

Tune is fine, do change the cat out only for inspections. (Dont drive with it too much, will run a bit richer)
Dont abuse the launch control for flames..

The clutch has since been replaced so that wouldn't be a problem, and upon buying I was already planning on turning 2 step and flat foot shifting. It is cool and all but not really healthy for anything except your ego.

Thanks for the tip onthe oil change and changing the spark plugs did not know that. The seller mentioned that during the crash with the pole a line of his oil cooler broke and he hasn't come to fixing it so he replaced it every 5k km or so, atleast that is what he said. So I don't know how far every set of spark plugs whill last?

And for the oil leak it will indeed be a gamble and will be the first thig to be fixed but I don't exactly know the details of what might be the problem.

I don't see any comment about rust. That's what I would be concerned at first.
I'm on this board for nearly 2 years but turbo is not yet on the car - I had to cut the full car apart to fix rust prior to install power bits. Doing it yourself is quite cheap, having somebody doing it for you is expensive; chassis rails are easily 1500€ if well made, rear quarters and fenders are even more expensive to fix.
Being in Europe, Prestige Spares or Bofi in UK, SPS in Germany are selling parts for very cheap so I wouldn't be too concern with parts availability if something goes wrong (which may very be with heavily tuned car).

Having T-OEM, past owner, telling you what happened with the car is quite good news ;) Setup seems quite well sorted based on comments.

I was quiete surprised to find the previous owner to be honest, but it indeed helps a lot with making a decision.

I am not concerned that something breaks because that is probably bound to happen over time, but that is to be expected. But what I am concerned about is the amount of times it'll break. If the build is correct and maintance is good no problem, but I don't want something that has a 50/50 chance of breaking on me everytime I get in after driving 10k km.

And to come back on to your concern, it doesn't seem like there is any rust on the car which is a huge plus.

should be a slight leak, but needs looking at what it is because its quite the setup: heat exchanger, sensor plate, oil cooler sw plate, oil filter.. i believe.

i do remember hearing something about the oil cooler not being connected or something.. would advise fixing whatever broke and reconnecting the cooler before running it on track. (make sure it’s clean and no debree is in the lines, and cooler itself)

i ran even colder plugs at a grade 8, they lasted even long enough for a full oil change interval 8-10k km. So grade 7’s should also work fine.

That's good news, you can remove the door sill trim plate and check inside of the body to double check.
25€ endoscopic camera can help you to control shape of the hollow part of the car to be sure.

I wasn't really planning on tracking the car, just something as a fun dailyable car. But it is always smart to reconect the oil cooler as soon as possible.

And as of the leak I can't really guess how big the fixing job would be because I haven't taken a look at the leak yet but I'd expect fixing it wouldn't be that big of a problem. Correct me if I am wrong though

Yeah rust is a big miata problem and a pain in the ass to fix if even fixable

Oh yeah the car was totally rust free apart from slight surface rust on the left front chassis leg around 50 euro cent spot.
also some paint bubbling at the rearward sills(left one had a bubble or 2 more than right side). However when scoping the insides it was quite allright, after that i sprayed about 2 large xl cans of textyl ml into it untill it started leaking wax out of all holes.
i did also clean the drainages every year before fitting the hardtop for wintertime.
chassis legs were paint-scratch damaged due to a week of way to low ride height.

I got it from a wreckers place where the left front was damaged, fender, bumper and all suspension parts were replaced. Chassis leg was straight, had to do some massaging around the fender mounting plate/wing.

take note this was 1,5-2 years ago..

as for reliability during my ownership:
always warmed up the engine, sent it as hard as could, never broke.. apart from losing the crank pulley once.. (crank was not damaged)

Ask me how I know! :rofl:

https://cimg7.ibsrv.net/gimg/www.mia...3a24305baf.jpg

https://cimg1.ibsrv.net/gimg/www.mia...70e1087c1e.jpg

https://cimg1.ibsrv.net/gimg/www.mia...bcc9ef1f67.jpg

That is great to hear that maintanance up to that point was great to say the least. As for the rust spots as you said it is just surface rust which doesn't seem to be that big of a problem and can be fixed in the long run by respraying the car or replacing parts like the front fenders.

Also good to hear that the build held up for that long already and that it wasn't babied in the time that it lasted. I was planning on using it as a kindoff daily so I don't want it to break every time I smash the throttle.

So daily driving the car wouldn't seem like a big problem if I hear all of this.

from what km has the car been fitted with a turbo if I may ask?

Jeez that doesn't seem like a fun job, glad you fixed the car up though in the end!

Do take note that usually these cars rust from the inside-out due to questionable drainage designs.(thanks mazda)

not sure really.. got it at around 142k km.. might have boosted it around 155-160 or something? It was my daily aswell..

So it is running boosted for about 30-35k km without any problems while being driven pretty well. That is a good sign.

Well I'll just wait out the compression test results and a list of parts that all have been overhauled in the engine and than I'll make a decision based on that. I'll come back to it.

Insane to have found the previous owner on the forum, would love to meet up some time if I come to buying the car. I don't know where exactly you are located in the netherlands?

Thank you for all the information everybody.

This is why pics are good hahaha

Any updates on the car?

I wish I had, currently still waiting on compresion test results.
With all the tips I got that is going to be the deciding factor.

I am not that woried about the test because the engine does run really well but still after all the reply's.
Correct me if I am wrong, but I think it is better to wait for the results of the comp test instead of buying right away

Agreed, wait for the results before pulling the trigger. Taking a while for the seller isn't it? I mean he can run to a local parts store and rent one (at least in the U.S) and it doesn't take long to conduct the test. Or drop it off at a shop for a day and pay a small amount to have it done for him.

yeah, indeed. Thought the same thing. But still it will probably be worth it in the end I hope.

Because if the comp test checks out the car is pretty much in excellent shape, mechanically. Because from the outside the car is far from perfect. A lot of dents and such but no rust atleast. Just surface rust on one paint spot