Help me chase 300whp
 

Hello,

I’m looking for some help chasing power from my current set-up, failing that, recommendations on what a new set-up should look like.

The current set-up is a completely reconditioned NB 1.8 engine (balanced, forged rods, stock pistons (slightly machined to a lower CR from 9.5:1 to around 9.35:1) NBFL VVT oil pump, new crank pulley, stock head.

The manifold is a ‘flowy log’ with inspiration from Sturovo / people on here, using 1.25” SCH40 primaries. The manifold flange was reverse engineered from the gasket and therefore larger than the ports, this meant the 1.25” SCH40 pipe was actually too small for the flange and needed beating out to fit. The manifold is mildly polished.

The turbo is a port & polished hybrid TD04L-19T (was a TD04L-13T which made 242 whp at 14psi on the old engine). The downpipe is 2.5”, with 2.5” straight through to an MX5Parts back box (muffler). The back box isn’t the best design in the world with a central chamber and 2.25” twin tips, although I have taken the back box off and seen zero difference in spool or power on maps/Virtual Dyno.

The old engine (same setup but standard 9.5:1 pistons) made 242whp at 14psi on the 13T. New injectors (700cc DW’s), 19T billet wheel on the turbo new head and rebuilt engine, produced 250whp at 18psi. To say I was disappointed was an understatement. I was shooting for 300whp and achieved 8 more than before after spending around £2500.

We couldn’t get the turbo to make any more boost on the 10psi wastegate and EBC so plumbed in a small pipe with a hole in it to help the EBC vent more, this achieved ~18-19psi & 250whp.

My current thoughts are:-

· My manifold is crap and needs redoing in the style of Absurdflow / Wittyworks and keep the TD04L-19T and turn the boost up.

· The TD04L hotside is just too small at higher RPMs and is the bottleneck, creating high back pressure and EGT

· Change manifold, turbo, DP & exhaust to …. Something else. Absurdflow / Wittworks, EFR / GT3071R????

· The stock head cannot flow enough (although looking at a lot of the builds on here the head should be good for many more horses than I currently have). IAT’s continue to rise up to redline at 18psi and I read when they stop rising this indicates the system has stopped ‘flowing’ per sé.

Sorry for the rambling. I’m quite pissed off with only making 8 more horsepower and 300 really was the magic number I was looking for. I want to easily slide past E46 M3’s, not chase after them and battle to get past.

I'm on crap wifi at the moment so can't upload pics to this post but will try to update shortly.

Should also note, the 250whp map also got a Skunk2 throttle body and ported IM to match.

I did wonder if the original head had had work done to it, but I find that hard to believe given the condition the car was in when I bought it.

the #1 reason is the tiny turbine/hotside on that turbo. either upgrade to a vf, or scrap that setup altogether for EFR hotness

I never saw the appeal of upgrading a td04 unless you are bored and/or doing it for free

The hallmark of a maxed-out turbo is "more boost but no power". You're there.

If you want a specific result, the easiest way to do it is to study those that have come before you and duplicate the important aspects of their build. With your bottom end and injectors, you're a hotside swap away from an easy 300whp, with lots and lots of headroom should you decide you want more.

So, in short, use this: Trackspeed EFR Turbocharger System

Do this:

https://www.miataturbo.net/dynos-tim...17-5psi-94656/

Or this:

https://www.miataturbo.net/dynos-tim...d-95108/page2/

Or this:

https://www.miataturbo.net/build-thr...2/#post1454492

Or this:

https://www.miataturbo.net/diy-turbo...ase-car-92683/

Or this:

https://www.miataturbo.net/build-thr...8-build-95308/

Thanks for the quick responses guys, I'll read the threads and take it on board. I am reticent to change the turbo completely at this point BUT given the instant response stating the tiny TD04L is the issue, I may have to bite the bullet.

Still trying to upload photo's :-/

Turbo too small. There are many journal bearing garrett clones on ebay, spool is not great, but better woth a good manifold. Patsmx5 has run multiple different setups with ebay turbos, the lowest whp of which was 350whp on a gt2871r clone. 200 dollar turbo, 1000 dollar diy rebuild engine.

Get a tse setup (best spool from bw efr turbo) most expensive, least amount of parts, best quality turbo

or kraken setup (comes with full exhaust for 1100 shipped) but need to choose a turbo contact kraken miata on facebook

Not having any info on your ic setup makes me guess that is also not efficient. Make sure your ic core is a good one, minimize piping bends... Buy a track dog racing over the rad ic setup if you want the easy button.

Thanks Thumpetto007 the intercooler is a generic medium sized cooler from eBay - 550x140x65 with 2.25" pipes.
It's placed as far forward in the NB bumper mouth as possible and I have shrouded in the intercooler and oil cooler, typically the intake air temp pre TB is around 20°c above ambient.

One full pull (after many) goes from ~10°c to ~25°c at 18psi on a 5°c evening. On track it typically sits around 25 -30°c at at 10-15°c ambient, which I believed to be quite good.

Makes me look forward to my FlowForce injectors that are in the mail.

Or he could ignore all those inferior chinachargers and get an ihi vf39 and change nothing else and be able to hit 300whp.

I would also not recommend the TDR intercooler at all for 300+ setups.

Oh really? Thats the first i heard about the tdr not being good. I was under the impression they are the best on the market.

Is the ic core just too small for over 300whp?

Add a bigger turbo and you will hit your goal.

Ask Nigelt how he likes his China Charger.

OP, 18psi is well versed with the WRX / STI world. He is not just guessing here.

Correct. It's a small tube/fin core that simply can't deal with big power.
There are at least 3 other cores that are just as good, but also come in sizes and configurations capable of supporting 300, 400, etc.

I did a 6758 car ~18mos ago for a customer in the Midwest, he asked me to keep his TDR IC and I was not impressed with it. Had I known, I would have insisted on changing the IC setup in that car (~300whp pump gas track car).

I mean the pipe routing is the correct way, but just needs a different/bigger core. I would hope your ic kit goes over the rad. Its the easiest way to achieve the least amount of bends, oem radiator supports are just replaced with longer ones for pipe clearance. Oh and the minor added cost of running hood raisers, not the hood prop.

It's not the correct or the best way. I don't even think there is such a thing.

In fact, have you ever considered the amount of direction change that the air has to make at the end tank in a typical over the rad setup?


https://cimg6.ibsrv.net/gimg/www.mia...50295c30a5.jpg


I'll take 5 smooth big radius bends over that any day.

Images attached as promised. sorry for the slow reply. I've been reading the links and deciding what i want to do (can't find a vf39 in the UK).

please ignore the log, that was merely to show boost and temps, I was n the middle of tuning Closed loop boost control hence the crazy log.

Are you sure? There are also tons of other VF turbo's that are nearly identical to the 39, they are extremely common here. In fact, I even have a near-new VF48 I'll be selling soon

18psi, what do you think to this? It seems a bit too cheap to be genuine and I thought the VF's were ball bearing cores not journals?

Link

Sorry for needing to be spoon fed, I am severely lacking in time at the moment although I have managed to read the suggested posts and the EFR is looking very tempting, need my wallet to agree though.

Thanks

Wilson

That's a chinese knockoff. I would never spend GBP 320.00/ US $441.68 on it

CFM X 0.069 =LBS/MIN

https://cimg2.ibsrv.net/gimg/www.mia...9cac8bd89d.jpg

Thanks Mr Steve, although this is for a TD04H-19T, with mine being a TD04L-19T would that change that map (even though it is specifically called a compressor map).

Thanks

I had originally thought that you may be able to get there by adding a cutout early in the exhaust. This map makes me think it wont get there. Should be very little diff between td04h vs L, AFAIK

the restriction is in the turbine, so adding an exhaust cutout doesn't help it flow more.

is there an echo in here or something?

Yep. you :)

You can get either a VF39/43/48. They will all get you around 300whp but probably not much more than that. The TD04L turbine is tiny and even though you have a 19T wheel the turbine is not sized correctly to be able to take advantage of the compressor wheel. The WRX guys that upgraded to a 19T never really made much more power.

Not a requirement. An upgraded damper would be a good idea, though.

I too would like an upgraded damper on our engine, suggestions where to source (currently seeing as my go to sources, you and 949, are not carrying them at the moment)?

Bringing this up again as i have been rearead quite a bit around VF43/48 as suggested and just have a nagging feeling that I may may be pushing it to the edge of its capabilities giving me ~300whp, and I'd rather something reliable than constantly stressed (like my poor TD04L-19T is right now).

So, asking the same question above, could i Transplant my 19T wheel into a TD05H-16G with new cover plate? Would this get me where I want to be or would it be laggy as hell?

Also, i im now running a lovely Kraken cast manifold, downpipe and 3" exhaust, as i was sick of reparing my DIY effort.

Cheers

Wilson

there's thousands of Subaru's making 300whp for decades on the vf.

do you just like overthinking things? if yes, then by all means do some weird off the wall hybrid turbo setup and enjoy the small potential that it might not totally suck vs pushing the easy and cheap button.

turbo's are not "stressed" when they're within their appropriate comp/turbine maps.

Sorry, yeah i do overthink everything. What i mean is, if i fit a VF48 and run it at 20psi to achieve 300. How long is is it going to last before it shits itself. Given I've gone through two TD04 cores at 18psi it makes me nervous it wont be very reliable .

tons of guys running td04s at 18 peak for 100,000+ too

you probably started with unhealthy ones or some other issue.

ive seen 200,000mi on a td04 before

I run my TD04 @ 18psi on my WRX, has well over 200k on it.:wavey:

Well my first one killed itself due to a lack of oil (AN-3 pipe) and my latest core has developed more radial play than i would like, to the point where ive slightly enlarged the housing. And thats with AN-4 pipe and at least 600ml/min oil flow.

Looks like a rebuild kit is required before the nurburging trip next week. Although i was using the repair as an excuse to upgrade.

it's like 50 bux for a decent rebuild kit. can't really beat that price.
in fact if you want a spare td04 (started smoking, so needs rebuild) and a rebuild kit I can probably send you both for $50+ship lol

That is an amazing deal, if OP doesnt buy that I would lol.