Need some help with my budget upgrade path plan
 

Hello y'all,

I am new here and I got my 91' Miata in the summer. I had been driving it and had a lot of fun. Recently I decided to do incremental upgrades to improve the car bit by bit, with turbo in the slight far future. Since I am still a student, budget is tight so I want to best possible improvement for the smallest amount of money. I started with the catback. I bought an enthuza setup hoping to improve the sound and make it run a bit better. After jacking up the car for the first time I was surprised to see the cat had been removed and a narrow pipe is welded in place of it. So, I need to now source even more parts to get the catback on.

Through the surprise forces me to spend more money, it also makes me think about what I want down the road. Because of the weld, I need to at least replace the stock downpipe and cat. Since I am spending money to replace some of the parts that will need to be replaced eventually, it got me thinking maybe this is a good time to replace the header with a long one. But then if I do an engine swap or turbo down the road, that will need to be scrapped. So right now I am very conflicted on what to do next as I don't want to throw away money and at the same time I need to put together something before March to pass emission.

So I guess ultimately, I want to know more about how much it would cost realistic to turbo from my current setup and what parts are reusable and whether 1.6 turbo is the "right" way to go. I have read a great amount into the debate between 1.6 turbo vs 1.8 swap then turbo. If money and time are no objects, no doubt the latter would be better. Currently, I am leaning toward going a 1.6 turbo setup with used parts since it costs significantly less due to demand. I have seen ads show up with almost complete kits that goes for ~1k. I am not sure of that's a realistic number to expect or that money can only get me cheap parts. Also, from the stuff I have read about turboing so far it seems that there are overwhelming amount of things to worry about such as ecu, spark plugs, intercooler, etc beyond the basic redirection of air from exhaust to intake. At the same time there are also clutch, rear diff, and other parts that need to be replaced. From the limited knowledge I have I cannot fully understand the true cost and time commitment it takes to do all that.

Sorry my thoughts are a bit jumbled from all these options. In brief, I want to get opinions on what is the best course of action now (cat and downpipe choices) with regard to my exhaust system that would minimize my loss down the turboing road (1.6 or 1.8) given that I will be staying N/A for a while. Then, how should I approach turboing since I have minimal experience in this without blowing up my only car (don't need it to commute, but still). Is it possible to do the most simple turbo setup first and then expand on it later on, ideally one without messing with fuel lines and pumps?

While we are at it, anyone got a spare stock downpipe I can have for not a lot of money? Please let me know.

Thanks for reading my post!

buy a used down pipe and cat. Depending on your location it should be $30-$80 ish. But second hand cat is always a guessing game for passing emissions but you don't have much of a choice. Or make friends was a maiata owner and swap cats for the test.

if you can justify the price of a oem used exhaust I wouldn't even think about the turbo side of things yet. Spend your time learning from reading and your money setting up the rest of the chassis with supporting mods.

1.8 brakes
1.8 torsen drive shaft and axels
a good suspension and tire set up (see the better billstein ebay thread for cheap ideas)
coolant re route
megasquirt ECU and play with tuning.


Have fun with that until you graduate and have money to throw at the car.

Yeah I think you'd be better off just trying to find a stock replacement exhaust for now. One that will get you through an emissions test. A turbo should be one of the last things on your mind if your still in school with just one car. If you jump straight to it, you'll have a money pit of a car and you won't be able to enjoy it for what it is.

So basically I'd focus on simple supporting mods now that you know you won't have to replace down the road.

As far as estimating time and and cost for a turbo setup... I find a good rule of thumb is to triple your best guess :)

Though I am no longer in school (that was a LONG time ago!), having way too many hobbies, and another project vehicle (Bronco) has kept my Miata progress slow. I also have a 1.6 car. This week, the plan is a 1.8 swap and Rotrex, though a turbo is still a possibility, and I'm still looking hard at the LFX swap.

I started with baselining maintenance, upgrading parts during that process. Brakes, then suspension, wheels/tires, safety (rollbar/harness), etc. I've done pretty much everything except the engine, so now I'm at a decision making point. If I stick with the BP, I'll be ordering an MS3Pro sometime early next year, the upgrade path being engine management with the 1.6, then a 1.8 swap, then forced induction.

As long as your engine is running well, work on the rest of the car, and get it ready for the power. Plan your approach. Learn the car inside and out. Save money in a 'war chest' and when you see a good deal on a part you're going to use down the road, grab it.

Any forced induction setup is going to cost ~ $5k with the necessary supporting mods, not including an engine build and with you doing all of the wrenching. If you really bargain shop and get some good deals on used parts, you can probably beat that, but not by much.

As far as you current issue, just find a stock manifold and downpipe. They should be dirt cheap in any junkyard or at one of the Miata salvage yards on the 'net.

$1000 for a MS and wideband O2 sensor
$500 for a 1.8 diff
$200 for 1.8 brakes
$1000 for 1.8 swap
$250 for injectors
$400 for clutch
$2000 for diy turbo setup

There I broke down costs and the order that you need to do them in.

Wow, this seems a lot more than I have expected. I have read that Greddy turbo for the 1.6 could give a modest amount of boost for ~1k without tremendous amount of work while keeping the rest of the car as is. I don't expect to go as fast as most of the enthusiasts on the forum. Just something to have fun with without breaking the bank or the car. I guess I was wrong.

Thanks for the advice on the downpipe and cat. I am not sure if I can find them locally since I live in a relatively small town (Austin) and 1.6 parts are hard to come by. As for the cat, I was thinking maybe it's a good time to upgrade to a less restrictive one to couple with my about to install enthuza catback (2.25") to get more speed and prepare for the future. The downpipe I guess I'll have to source from online. Since people on the forum drops their stock downpipe when they install a turbo, I thought I could source one here for not a lot of money. Does anyone have a spare?

The Greddy kit is garbage.

https://www.miataturbo.net/attachmen...ine=1419026832
Some would resent that analogy!

If the noob can contribute....I say the GReddy kit is an excellent low hp/$ solution that you can squeak by with the 1.6 drivetrain intact as long as you drive like you have sense AND the great thing is there are people(ARTech) who make better than original replacement manifolds and downpipes if/when in the event the originals crack. :)

I am under the impression that most people on the forum have a high end setup. Could you elaborate on why something is bad in an unbias fashion?

the greddy is a restrictive kit and doesn't have much potential. However, if you just want to play around with turbos on the cheap I don't see why you couldn't. Most be don't recommend because the "do it once do it right" moto.

The only thing you really should never consider is the ebay taco taco kits. unless you want to practice welding cracks.

but always ECU first. that's going to cost you $400-$1000 and you can't do any turboing reliably without it.

This is the nail being hit on the head. Exactly what I have spent.