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-   -   The Cheapest EFR Build You Ever Did See (https://www.miataturbo.net/build-threads-57/cheapest-efr-build-you-ever-did-see-99176/)

Romba 01-28-2019 11:30 AM

The Cheapest EFR Build You Ever Did See
 
Hey everyone! This thread will capture the cheapest, most budget-minded EFR 6258 build you will probably ever see (claim completely unsubstantiated.) I’m a senior mechanical engineering student, so this will all be on a college student budget, AKA this year’s tax return and some internship money. I had this 6258 fall into my lap about a year and a half ago, and before then had no realistic plans to turbo the car (1993) in the near future. Now here we are.


A bit about the car as it sits: it’s a 1993 that I paid $2200 for bone stock with 148,000 miles. It’s not the prettiest on the outside, has a crappy non-original paint job, the front bumper cover isn’t in great shape, and has a couple of dings and dents, but overall is straight and rust free. Since I bought it two and a half years ago, it’s received a Hard dog rollbar, Hawk HP+ pads all around, NB2 seats so I don’t break my neck in a wreck, Koni yellows with Koni coilover kit and eibach springs (600/350, IIRC), a blackbird fabworx lexan spoiler, and 949 6ULs with Hankook RS4s. It’s a blast in the mountains, and good fun at autocross, even though I’m slow.


Trying to embed the image but it keeps nuking all the text in my post, so here's a pic:

https://imgur.com/a/EFTe1Oy


I’m posting this now, before I have many parts, both because I’m super excited to finally make this happen, and because I’d like to get some opinions on part selection - with the fact that this is a tight-budget build on a non-essential car kept in mind. That said, the following is my currently planned parts list. The current plan is to run about 10psi, which based on BW’s Matchbot should make around 200whp on my 1.6 - I don’t want to throw any rods right now.




  • EFR 6258 (using integrated CRV instead of a BOV, at least to start - I do want those noises…)
  • Internal wastegate (external down the road just for those sweet, sweet EWG noises)
  • Lancer Ralliart Charge Air Cooler (so I can keep my A/C)
  • RX8 injectors - blue body or yellow body
  • Speeduino plug and play ECU (again, it’s a budget build. Plus as an enginerd this seems like a super cool concept)
  • Tubular manifold I paid $13 shipping for, plus probably a case of beer to my buddy to weld up its crack - I wish I could find one of the taco cast manifolds, but for a 1.6 and a T25 flange they don’t seem to exist.
  • Exhaust: 90 degree v-band elbow off the back of the turbo, then take it to the muffler shop that the local car folks like to be taken out the back with a vibrant resonator.
  • CXRacing oil line kit
  • Basic hose coolant lines
  • Supermiata spring 3-puck clutch kit, or ACT 6-puck if the supermiata doesn’t come back in stock
  • AEM wideband
  • Manual boost controller, with the plan to try and utilize the EFR’s integrated BCSV down the road, if possible
  • Prosport boost gage, or TSG-1 turbo speed gage/boost gage if the tax return is especially good
  • GM IAT sensor
  • Stock fuel pump and FPR (should support 200whp, if I understand what I’ve read.)
  • Possibly coolant reroute.
Total parts list is currently about $1500.


So yeah, that’s the plan, and it will be set into motion as soon as I get tax returns back. The biggest challenge I forsee is tuning, so I’m thinking about doing clutch (current clutch slips if I throttle under hard cornering, so it really could use replacement) and speeduino before the rest so I can familiarize myself with tunerstudio before I have to deal with boost too. I do have a coworker at my co-op (internship) who is a pretty solid tuner, but the car will be built a state away in my parents’ driveway, so it needs to run well enough for an hour and a half highway cruise.


I’d love any and all feedback, even if it’s you dumb kid, it’ll never run and your parts are all garbage!!!!!
I look forward to chronicling what should be a fun build and a great learning experience.

matrussell122 01-28-2019 11:51 AM

Do the flow force injectors instead of the RX8 injectors, you will need the reroute and either supermiata or flying miata happymeal clutch.

der_vierte 01-28-2019 12:01 PM

Sounds like a plan.

I could be wrong, but the exhaust manifold will be a challenge, because of the size of the EFR. If you look closely, you will see that the EFR manifolds place the turbo more to the front of the car.
Don't know if there is space for an elbow on v bands with your manifold.

Speeduino is cool!

ryansmoneypit 01-28-2019 12:50 PM

The CRV is already very loud. borderline as loud as my TurboSmart BOV i used to have.

Romba 01-28-2019 12:52 PM


Originally Posted by matrussell122 (Post 1520695)
Do the flow force injectors instead of the RX8 injectors, you will need the reroute and either supermiata or flying miata happymeal clutch.

Yeah, coolant reroute will most likely happen. May try to DIY it if budget requires. I'll take a look at the flow force, and the Supermiata is the plan, as long as it comes back in stock.


Originally Posted by der_vierte (Post 1520697)
Sounds like a plan.

I could be wrong, but the exhaust manifold will be a challenge, because of the size of the EFR. If you look closely, you will see that the EFR manifolds place the turbo more to the front of the car.
Don't know if there is space for an elbow on v bands with your manifold.

Speeduino is cool!

Hm, interesting point. I know I've read that people have some height issues with EFRs but I hadn't thought about length. Makes sense, they are intentionally longer so the bearings can be paced farther apart... That'll be something I'll have to look at when I get started, thanks for mentioning it.


Originally Posted by ryansmoneypit (Post 1520709)
The CRV is already very loud. borderline as loud as my TurboSmart BOV i used to have.

Awesome, thanks for the info. Gotta have those sweet, sweet boosty noises.

x_25 01-28-2019 02:51 PM

Which tubular manifold? Is it made from thick tubes or shiny thin ebay ones? If the later, it will litterally crack again in a few hundred miles.

Romba 01-28-2019 04:14 PM


Originally Posted by x_25 (Post 1520737)
Which tubular manifold? Is it made from thick tubes or shiny thin ebay ones? If the later, it will litterally crack again in a few hundred miles.

I haven't dealt with any other manifolds to know. Here's a pic: https://imgur.com/a/gyMymGY

The crack is at one of the welds to the flange, not just in the middle of the tube or anything.

ryansmoneypit 01-28-2019 09:02 PM

No, dont use that manifold. Just dont. An EFR is heavy, it will snap that manifold like a twig

Romba 01-28-2019 10:04 PM


Originally Posted by ryansmoneypit (Post 1520791)
No, dont use that manifold. Just dont. An EFR is heavy, it will snap that manifold like a twig

Hmm, noted. Any suggestions, then? I definitely can't afford the $700 EFR-specific manifolds... I'm thinking an ebay cast with a T3 to T25 adapter or a CXRacing tubular. I can't find a 1.6, T25 cast manifold on eBay to save my life, but 1.6 T3 manifolds are available... And there are some that place the turbo more forward like der_vierte mentions. Thoughts?

SpartanSV 01-28-2019 10:35 PM

Mild steel schedule 40 weld els and a mig welder.

borka 01-29-2019 07:18 AM

All the shiny manifolds on Ebay are shit and will crack real quick.

If you cant spend the money on a proper kraken manifold/Downpipe, you can get the cast Ebay T3 manifold, then drive studs or bolts into the t3 holes, mill them flat with the surface and redrill and tap new holes for a T25 bolt pattern.

Greg from the car passion channel did it on his broke and boosted build.

Its ghetto, but it worked.

sixshooter 01-29-2019 07:43 AM

That's terrible advice.

If you can't afford a kraken manifold, which is a bargain manifold, you cannot afford to turbocharge your car. This is reality.

Romba 01-29-2019 08:18 AM


Originally Posted by sixshooter (Post 1520827)
That's terrible advice.

If you can't afford a kraken manifold, which is a bargain manifold, you cannot afford to turbocharge your car. This is reality.

I've been waiting for a response like that. I'm pushing it on the budget here, I know this. But I also hadn't heard of kraken, somehow, and that may be doable. Thanks.

Romba 01-29-2019 08:19 AM


Originally Posted by borka (Post 1520824)
All the shiny manifolds on Ebay are shit and will crack real quick.

If you cant spend the money on a proper kraken manifold/Downpipe, you can get the cast Ebay T3 manifold, then drive studs or bolts into the t3 holes, mill them flat with the surface and redrill and tap new holes for a T25 bolt pattern.

Greg from the car passion channel did it on his broke and boosted build.

Its ghetto, but it worked.

Interesting idea, but I think I'd try the little flange adapter before I'd go this crazy.

borka 01-29-2019 08:47 AM


Originally Posted by Romba (Post 1520829)
I've been waiting for a response like that. I'm pushing it on the budget here, I know this. But I also hadn't heard of kraken, somehow, and that may be doable. Thanks.

Kraken makes awesome manifolds with matching downpipes, that's what I'm running. Highly recommended.

For the money, Theres nothing better.

T3-t25 adapter is ghetto as hell, pushes out the turbo to the point it might not even fit in the engine bay.

I say go kraken or wait till you can afford it, no sense to spend a few hundred less and have terrible parts which are crucial to the reliability of the whole setup.

Romba 01-29-2019 09:15 AM


Originally Posted by borka (Post 1520831)
Kraken makes awesome manifolds with matching downpipes, that's what I'm running. Highly recommended.

For the money, Theres nothing better.

T3-t25 adapter is ghetto as hell, pushes out the turbo to the point it might not even fit in the engine bay.

I say go kraken or wait till you can afford it, no sense to spend a few hundred less and have terrible parts which are crucial to the reliability of the whole setup.

Good point on the adapter. Yeah, I guess I'll just go kraken. $450 in manifold hurts but to your point it is pretty foundational. I think I'll still go exhaust shop special on the downpipe and the exhaust, can always come back later and pick up a kraken or other higher quality EFR downpipe.

andym 01-29-2019 09:21 AM


Originally Posted by Romba (Post 1520834)
Good point on the adapter. Yeah, I guess I'll just go kraken. $450 in manifold hurts but to your point it is pretty foundational. I think I'll still go exhaust shop special on the downpipe and the exhaust, can always come back later and pick up a kraken or other higher quality EFR downpipe.

I seem to recall his all inclusive kit with hardlines and down pipe and exhaust was rather reasonably priced.

matrussell122 01-29-2019 09:31 AM

It is typically cheaper to have a mass produced downpipe like the kraken rather than a special one off from an exhaust shop.

Also like sixshooter said above, there is nothing cheap about turbo anything. If this is your only vehicle i would not recommend a turbo at the moment rather spend your budget on a good ecu like a MS3X or MS pro then turbo your car when you are out of school.

Romba 01-29-2019 09:34 AM


Originally Posted by andym (Post 1520835)
I seem to recall his all inclusive kit with hardlines and down pipe and exhaust was rather reasonably priced.

I'm not seeing full EFR kits on his site, just manifolds. His standard T25 kit (2.5 inch v-band downpipe, EFR is 3 inch) comes out to ~$900 shipped, which is definitely reasonable for the kit, just not in my budget.

Romba 01-29-2019 09:37 AM


Originally Posted by matrussell122 (Post 1520838)
It is typically cheaper to have a mass produced downpipe like the kraken rather than a special one off from an exhaust shop.

Also like sixshooter said above, there is nothing cheap about turbo anything. If this is your only vehicle i would not recommend a turbo at the moment rather spend your budget on a good ecu like a MS3X or MS pro then turbo your car when you are out of school.

Interesting thought, I'll do some comparison shopping. But I'm not seeing an EFR downpipe on his website.

And this car is 100% toy, not my daily, so if it goes down for a while it's not the end of the world.


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