Weakest links in the chain
 

Since a chain is only as strong as its weakest link, I was hoping experienced turbo-ers could help me identify the most common points of weakness in a turbo build. I’m aiming for 250whp out of a 1.6 so I need to ensure everything is optimised. In no particular order:

Injectors. I’m told finding ECU compatible injectors that your target hp output sits in the middle of the range of application is as complicated as it gets. Is this really true? Are there more effective/ efficient options?

Intake. I understand that adding a sensor compatible with the chosen ECU can allow the removal of the restrictive 1.6 air flow meter (and airbox) altogether? If this is the case, I can’t see any reason for restriction in the intake to impede (airflow, and thus) power? Obviously CAI etc. maximise density etc. but generally, are there any potential intake issues I’m not seeing?

Turbo. Not going to pretend I understand the interaction between turbine housing and compressor size in anything other than a general sense. Though response and power/torque curves will vary correspondingly, let’s just assume I use a turbo that can shove enough air that turbo size or efficiency is not restricting performance. Anyone who wants to suggest a turbo for the 1.6 NA that gives quick spool up but doesn’t max out/melt trying to get 250whp is welcome to. I’m planning on getting the head ported and gas flowed (possibly oversized and shaped valves) to promote earlier response, and the TD04-13t is used and recommended in a lot of prefab kits here in the UK but haven’t seen one making figures I’m aiming for.

BOV. If linked to MAP sensor and suitably accurate and responsive BOV shouldn’t cause a problem right?

Waste gate. Must admit I’m not au fait with the nuances of waste gates just yet, but feel free to jump in with advice if there is anything waste gate related that has the potential to impede the set-up.

Other than that am I missing anything? (I understand the need for the additional cooling – including intercooler – and oil lines etc., and the importance of unrestrictive exhaust.) IS there certain type of hosing or pipework that needs to be upgraded to? Where have you guys found the weak links are?

Any questions and especially advice welcomed.

Many TIA

you're missing the broken diff and slipping clutch

the rest of the questions are so obvious and beaten to death that I won't answer them

correct answer.

/thread

Youll also be on the edge of rod breaking territory.

Injectors... what? I have no clue wtf you are trying to ask.

Intake, yes run a MAP sensor with the ECU you choose and delete the AFM. Youll need an IAT too.

turbo, td04-13T will be completely maxed trying to hit 250 WHP, you probably wont make it.

BOV, just connect it the way its supposed to be connected and forget about it.

I hava an idea, maybe it has been presented before. Can I / we/ us, make a new sticky with the simple, non-explanation parts list for the 250, 300, and 350 hp build? I think it would be quick to make and certainly help to cut down on the problem at hand. Is this idea flawed?

Amazingly, even if you chew it up and place it in their mouth, they still don't get it.

This has been done dozens of times.

......but if anyone wants to put in the serious effort making "the post" I'll sticky it, sure.

I know. I just want to think it would help a few. Not all, but a few. The rest could just supply us with the humor we need in our lives.

I have some airplane travel time this week. I'll see what I can put together for review.

You write it, I will sticky it and claim that it comes from me for all the cats.

Apologies for the obvious resentment caused.

I will re-read what I have found and re-search for answers I didn't find/understand.

Feel free to close and/or delete the thread.

And thanks for input regardless.

We're not resentful, just tired and grumpy. Feel free to come back and ask more specific questions after you did some homework and we will help you out :)

My problem is that the homework I have done seems to always lead me down the route of a list of parts than a (for me) understandable map of how components impact on each other individually and a system as a whole. In 11 months when my friend is off to Canada, I'm buying his 92 1.6. Now I know I need to upgrade the diff to a 94+ (torsen preferably), and 6 speed will survive longer. And I have list of recommended components from spark plugs to injectors to ECUs to rods to manifolds to cat-backs. But bolting the list together will not teach me the interactions. For example: I read that you want injectors that have an effective duty cycle percentage, which I take to mean aren't being over- or under-worked. But I don't know - because I haven't found (in terms I understand at least) during my research - how to calculate the optimum size of injector. Do I think 'I want 250whp, so I need 620cc injectors'? Or do I think 'my engine is going to be force-fed 'x' cubic centimetres/litres of air per, so I need to find injectors which will provide 'y' amount of fuel per cycle'? In which case won't I need to decide on turbo first? You may be thinking 'of course you do! What a stupid question!' but that's what I don't understand. I don't know why people (much more intelligent and experienced than me) have arrived at the choices they have, and whilst I am capable of just accepting and copying that...maybe my questions should have been: what variables come into play when deciding on each part of the turbo system? I don't even know if this makes sense to you guys, but again: thanks anyway, and I'll go back to the boards.

Are we going to update the sticky? I say we don't mention any of the bandaids, should clear up some confusions.

oh god op... that big wall of text

You cant really "under work" and injector, especially in regards to newer technology. Its common practice not to exceed 80-85% duty cycle so that there is headroom for a number of reasons. Calculating minimum injector size is just a math problem. Simply searching google for "injector calc" nets many results, like this- Fuel Injector Calculator | Fuel Calculators | Resources | DeatschWerks

hasn't been updated in a while but it's still pretty legit. i paste this link all the time... (when I don't go MIA)

This thread has all the things you need in it. Now if you can not come to a conclusion or map together your own plan you should not be working on your own car. Call FM and throw money at their faces. The other alternatives which are actually more entertaining are to read faefae's build thread. Then Jeffs... lol. Jeffs is more useful but fae teaches you lots of things Including how to act or NOT act in the community.

https://www.miataturbo.net/diy-turbo...k-links-56507/

I swear a thread with this same title and question was just started yesterday.
I think it is past time to update the sticky.
I know these questions will still be asked, but at least we will have fewer people asking for aids and rx7 injectors.
I'll see what I can do at work tomorrow.

Lol.. i have a set of cleaned and flow tested 460 rx7... i need to head over to cr to rape someone.

Haha I guess I'll answer his question. Id recommend the GT2554R or GT2560R. May be a bit more expensive then what you're looking for but both those turbos will hit 250whp (or more on E85) with respectable spool on a 1.6.

I understand 2554 is roughly equivalent to TD04-T13 in max air-flow.

Just follow what I did:

https://www.miataturbo.net/dynos-tim...60r-e85-89501/

There's a lot more there; I just need to upgrade the harmonic damper, so I don't grenade the oil pump.