Turbo Selection: Sizing a Turbo

[Preloader]

You're correct, but I also believe the rigid disc was poorly designed. Plenty of race oriented modders mate rigid discs to solid flywheels with way more power, and don't break them as quickly as I did.

The rivets broke, and their location was really close to the center hub. The rivets on the sprung hub are much further from center and closer to the clutch pucks. It's a better design in my opinion.

 

[firstorbit84]

This thread needs more turbo.

http://www.ebay.com/itm/Turbocharge...Parts_Accessories&hash=item2a2d462733&vxp=mtr

$699

 

[Preloader]

Good call! Here's what I'm close to pulling the trigger on.

GT2859R:

 

[Graham]

Have u looked at the Borg efr turbos? They have way more top end available with small turbos plus spool fast with titanium turbine and forged compressors.. fancy units but may all be too big for the sonics.. I wanna see it done tho
Sent from my DROID RAZR HD using Tapatalk 2

 

[sonichead94]

anything is possible. 7 Second RX7 - Turbo bigger than the motor! - YouTube

 

[SONIC1.4]

I'm sure Vince will correct me if I'm wrong but the Rigid clutch is ok with the stock Dual Mass flywheel since it absorbs some shock loads.

The rigid clutch and lightweight flywheel didn't offer any form of shock dampening. Hard launches put alot of load on the clutch and with nothing to absorb them it quickly sheared off the rivets on Pre's clutch disk.

His new sprung disk adds back some shock dampening.

Yeah I gotcha, I plan on keeping the stock flywheel

 

[Preloader]

I have made my selection!!! Garrett GT2560 commonly referred to as a GT28.

It's popular for the Miata 1.6 crowd and is also stock equipment on S14s.

Next hurdle is the Intercooler. I will dive in the numbers and make a thread about calculating I/C needs as well as explaining bar style vs fin.

Downpipe will be 3" which I can TIG myself.

Should be completed on schedule by September.

 

[firstorbit84]

nice. why don't you just slap it on with the stock IC? it looks pretty stout already

 

[Preloader]

IC's can be categorized much like turbos into predicted horsepower ranges. The stock IC is not a weak component by any means for the 230-ish hp the the stock turbo is capable of.

But with the bigger turbo, the name of the game is going to be much more air flow. More air compressed to a comparable 22psi will generate a lot more heat to be extracted. That heat needs to be removed to restore the air's density. And IC efficiency is optimal with a 1-2psi pressure drop through it. If the IC is a bottleneck, that won't be achieved and all my hard work will be lost in less dense air being boosted into the engine.

tl;dr: the stock IC won't get the heat I will be generating out

 

[Preloader]

 

[sx sonic]

Looks like a good turbo and wooeee, Inconel. Now that's some nice stuff, I'm sure you've seen it in industry.

I got a question thou, What's with the 2 P/N? They look like identical turbos based off the specs on that page. I know it's kinda irrelevant but I'm curious.

Also it looks like you'll be required to fab up an intake or atleast modify you're ZZP. In which case you an get more direct and ideal angles from the airfilter to the turbo.

 

[Preloader]

The first p/n option doesn't include the high grade metals and is less durable to abuse....... So just ignore that one.

Yes the (DDMWintake) may need alteration, but they have many adapters that bolt to the cold inlet, and may only require a silicone 90deg bend to make it work.

Also the CHRA can be fitted with an AN -8 fitting for oil feed..... Mmmmmm braided SS oil feed lines.

The compressor housing can be fitted with a turbo speed sensor, and the turbine can be fitted with an EGT sensor. All good considerations to have while tuning this bad boy in for safe operation, and to confirm that the right turbo choice was made.

 

[sx sonic]

My bad on the intake. I suffer from CRS and mix up what I do remember with other things :/ lol

Boy do we love SS lines

Turbo speed is mehhh. Neato gadget and I imagine nice for tuning an R&D project like your's but nothing more than a wow factor for a bolt on.

Now that EGT fitting! that's really something. After a few engine rebuilds that thing and your wideband will = a super dialed in tune . How much do EGT probes run?

Does that model only come in an integral wastegate configuration? I don't know why but I've always liked the external wastegate design over integral. It just seems like it would flow better. I'm not sure if this is true or not it's just some gut feeling i have. The gains if any would probably be minimal and probably not worth the extra cost and fitting but it looks so much more bauss.

 

[Preloader]

The gt2560 doesn't seem to offered with a non-integral WG turbine housing.

Almost all the GTX models do. Talk about expensive though. They cost as much/more than the GT models and don't even come with a turbine housing. But they also provide a much larger range of performance. Namely more psi capabilities.

The gt2560 tops out right a 24psi on the comp map, while the gtx's continue efficiency right up passed 30. But I digress.

I want to do this not dream about it.

 

[SPOTWORK]

Now for the average guy that's not going to do head work what's a good choice, considering that low end torque is a strong point to the 1.4

 

[Preloader]

So far, all my sizing research has been done with Garrett Turbos. I like their history/origin. I'd say a good option for breaking passed the limitations of the stock turbo (gt14) without sacrificing daily drivability would be a GT20 series. I could spend a little time and find the preferred trim model.

Bigger compressor with a mildly sized turbine is the way to go.

 

[firstorbit84]

Now for the average guy that's not going to do head work what's a good choice, considering that low end torque is a strong point to the 1.4

I don't think that the 1.4 t really has a lot of low end torque. it seems like even with the small stock turbo it all is in the mid range.

that said I would also recommend a GT20 or 22xx series

 

[Preloader]

The 1.4 by itself has very little low end torque. But the tiny stock turbo does indeed start boosting at very low RPMs because of the small turbine.

So to be fair, the 1.4T has great low-end torque BECAUSE of the small turbo.

Peak torque doesn't happen til 3,500-ish RPM, but that doesn't mean it has horrible amounts of torque before that point, especially relative to the small 1.4 displacement.

For those looking to open up some headroom without going overboard, it would be wise to stay in the small frame series. After GT20 the mid frames start.

 

[SPOTWORK]

Thx for the info bud, it might not happen for be for a while but I'm sure many people are excited for a bigger mini turbo lol

 

[Preloader]

If you have an Ultragauge, here is a really easy way to get a close estimate of your peak crank horsepower......

Set a gauge to Airflow. It'll read in g/sec (grams per second) via the MAF. Keep an eye on the gauge while you push your car to it's limit.

Multiply your highest reading, mine was 180 g/sec, by 0.132277 to convert it to lbs/min. I get close to 24 lbs/min.

g/sec x 0.132277 = lbs/min

1 lb/min = approx 10 CHP

If you remember from the beginning of this thread, 10hp per 1lbs/min is a reasonable estimation.

That means I'm somewhere around 240chp. Subtract 15% (18% for auto) for power loss and you will have your estimated whp. Puts me at about 204whp.

Looks like I'll need to see 240g/sec with the GT2560 if I hope to get 270whp.