I'd think you'd get high 400s with it and add meth to get just over 500

 

No, you wont, unless you are running 30+ lbs. It is essentially a slightly smaller less optioned version of the 5558. Flows a few lbs/min less. Cody made 476whp on 26 lbs on E85 with cams on his 5557. Same boost on the 5431 would probably make (and this is speculation) around 450-460whp, and on pump gas you'd probably be in the low low 400's on that boost. Disregard that "600hp capable" label and look and lb/min flow charts and the compressor maps and results of similar turbos. It is similar in size to the s252et as far as flow potential for something else to compare it to.

 

I was guessing that it would flow 60lbs/min+

 

I've told you before that it doesn't though. A 5558 flows 54 lb/min, a 5858 flows 60.5 lb/min, a 5862 flows 63 lb/min, and a 6262 flows 67 lb/min (and usually can go a bit more). And the 5431 is a bit smaller than a 5558. So like I said it is a little over 400whp capable on pump gas without going crazy on boost. Keep in mind an s256et flows 58 lb/min and look what those usually make for power. About 500whp on 28 lbs on E85 on our platform, and on 35 or so you can dip into the 530-540 range. On pump most guys make 400-420 or so on 20-22 lbs.

 

Just did a quick search too and its even a little smaller than I thought. Right on Precision's web site it states the 5431 rated for 500hp and the 5831 rated for 585hp, but just to confirm I looked into it and it correlates perfectly to the flow rate I figured (usually 10hp per lb/min) and the 5431 with the billet wheel is a 50 lb/min turbo and the billet 5831 is a 58.5 lb/min turbo. So the 5831 has the same flow rate as an s256et, and the 5431 is 1 lb/min larger than a gt3076r and 3-4 lb/min smaller than a 252et.

 

I really like the 256et so I'd it's anywhere close to that I'd go for it I'll have to use my non existing salesman skills to sell brad on it

 

5831 is pretty similar. It'll spool a bit slower, but should hold similar top end. The 5431 will spool closer to a 256et maybe even a tad quicker, but it will be about 80hp less capable.

 

Ooooooooo a turbo seminar in progress lol

 

Who's putting it on?

Who's it for?

What's it about?

<checking in>

 

TURBO GOODNESS! All this talk makes me wanna go play around on the streets, then I look outside...

 

Does that mean that North Dakota has snow right now?
I think Winnipeg/Manitoba is about like us;
Our temperatures are hovering right around the freezing mark, and snow is generally only in the ditches, or where ever it was once piled...
Other than some light gravel in spots, the roads are all dry.
Last weekend I drove by a guy on a saturday cruise with his son... in a minty '68 Camaro SS!

 

We don't really have any snow left. Like you said, a little in the ditches and piles, but the roads are clear. It's not real warm, but should be right above freezing for a few days this weekend.

 

If all goes well, I should be in the turbo group. Still need to get my ass in gear and order gaskets yet

 

Do it! Get that GTX wheel in there so you can move some air.

 

All this turbo talk made me do this lol, and I just copied what I put in the Manitoba thread.

I'm bored at work looking through logs like usual lol, and I came across something pretty cool.

This is my good friend Lera's 06 WRX and this was from about 2 months ago. She had a cheap eBay turbo that the previous owner had put on, and she added a lot of good parts to it, and then she bought my friend Tyrel's turbo and went with an external WG. We finally converted it to speed density and wanted to make a decent 91 winter tune that was safe until we go back to E85 in spring and push that on Speed Density. So it has:

Stock EJ255 motor
6-speed 04 STi trans
HTA68 stock location turbo with the 8cm hotside (47 lb/min) and external WG
3" turboback
TGV deletes

These runs were both on 91 octane and BOTH ON THE SAME BOOST 19 psi, about a half hour apart on the same road.

Red Line: AFR dipping into the mid 9's to 10.0, 14* timing up top. Base map I made after getting the part throttle areas dialed in.

Gold Line: 11.7 AFR, 19* timing up top. The finished product. I have other in between runs as well as we were dialing it in.

Boost looks like it comes on late, but we were doing 3rd gear pulls which are really short with the 2004 STi 6 speed. At the 6700 rpm redline the top of 3rd is around 70-75mph, so as soon as boost starts coming in it moves through the gear quickly. I've seen full boost in 4th around 4000, and 5th around 3700. This thing shifts to 6th at 6700 at 115 mph



This turbo on my friend's 2.0 EJ205 made 380whp/350tq on 26lbs and E85, so we should see the same numbers on less boost when we can go E85 again in spring! Depending on how hard she wants to push it.

Thought I'd share my fun for the morning lol

 

Think it'll break 400hp on e?

 

If she wants to push it then it will. Its very capable. We made 380 on 26 lbs on Tyrel's 2.0 and ran it on 30-31 lbs for a few months at the end of last year when we didn't care if the motor gave. Well it never gave out lol but I'm sure it was making 400whp on 30-31. And the EJ255 makes power a little easier than the EJ205 because of the .5L displacement and slightly higher CR. Have to use caution when approaching that 400whp mark on any Subaru though, and make sure everything is on point. They don't tend to last real long above 400whp on stock motors.

 

Mark, taylor and I have been talking and agree that you should run meth 2.7 and a 50 shot this year that'll be the best bet for you

 

Or at least start on the 2.7 and see where we can get. If we have to start sacrificing ignition timing just to drop pulley sizes it will most likely actually lose power and put more stress on the motor rather than actually doing any good. Ideally, on the same amount of timing and a ported head like you have, you MAY pick up 10whp through the powerband at most. It will more likely be a little less, but then say we have to pull 2-3* of timing then you already lose that power right there. There is a balance between efficiency and power output, and its all about finding the best balance for the most performance. Meth will help that, but I still don't think a 2.5" is going to be beneficial. A 50 shot on a 2.7 with meth however

 

If mark goes 2.5 he'll pick up a couple hp but if he does 2.7 meth and a 50 shot he'll win most of the rematch this year. Take down some lnfs

 

merry christmas guys hahahahahahahaha i hope you all stay safe!

for the price of pulleys i can try 2.7, 2.6 and 2.5 and find the happy zone. meth will be a for sure. the rest remains to be seen. i havent said no and i havent said yes. nor do i want to really think about it or commit or comment right now. i just have other things on my mind.

 

You can borrow my kit

 

any updates on the 240sx?

 

I'd buy that for a dollar

 

Not really I lost the intake gasket so porting is on hold. I bought him a short shifter for xmas and I believe he's gonna start buying parts in the new year