I need Turbo Advice
 

Alright, since I have a good job and no debt Im building up the car again.

So far I have the MSPNP, AFM removed, and LC-1 WB.

I have a T3 "50", which I love (based on its compressor map)

The problem: I had the T3 rebuilt from some guy in Arizona and he didnt do it right. Unfortunately it was during school and I didn't have time to fight him. The turbo doesn't spin nearly as free as it should.

Should I

A) rebuild the turbo again, then send it to begi and get a manifold and dp. -> $1000

B) give up on this turbo get a used GT2554r, used begi mani, and used d/p -> $1000

C) get a new GT2860RS, begi manifold and d/p ->1300

2860 duh you will thank us when you up the boost. +1 in your budget i doubt 300$ is gonna make or break you right. The 2860 should be a nice spooling great midrange/topend turbo with alot of room for you to grow. + it should spool almost as well as the t3.

Yeah thats what I was thinking, Im wdonering if i should risk it on the chinacharger.

http://cgi.ebay.com/ebaymotors/GT28R...spagenameZWDVW

check these out
Attachment 216047
Attachment 216048
Attachment 216049 no contest dude Even if you dont trust ebay a new 2860 is only 800 or so bucks isn't it?

I say go chinese, everyone who says don't have never tried one and think because of the price its no good. From everyone with personal experience, I have heard nothing but positive things, including myself.

A for the cost
but D for the best results

D: GT2871R :bigtu:
(D is bad for budget)

2860 doesn't impress me. I'd rather have the 2560 or T3.

I cant find a cheap 2560

advise me people

Richard, do you honestly believe it will only take 2PR to reach 340BHP?!

340 x 12 x .00916 = 37.3 lb/min not 34.... 34 lb/min = 310HP

37.3 x 639.6 x 580 / 1 x 3650 x 97.7 = 24psi (2.6PR)

You cant add that much VE and expect the number to come out right....if that were the case I was making well over 300rwhp last time I drove the thing. After playing around on that site, I'm sicking with math...the results are out of whack....

If that calculator can't even determine to correct amount of lb/min is take to acheive a certain HP, then how the how is it going to calculate the rest....

Yeah thats what I had for the T3 50

I pulled the graph...the numbers were still REALLY high and misleading....I promise you it wont take 17psi to reach 225BHP.

whats your opinion brain on my scenerios brain?

It really depends on your goals. If I were me, I would take the GT2554R option and never look back. If you want more than 220-240rwhp, though, then you'll need the 2860.

Gt 2871 Arrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr

Why is your volumetric efficiency so high? I thought it was around 100 under boost or is above 100 possible? I forget how to do the numbers for the idealized models.

Has anyone tried to mate a T25 turbine side to a T04E 50 trim or 40 trim compressor housing? You would think it would work fine, no? I always wondered why the T25 based turbos only go up to the T28 on the non BB side of things but there are a million non BB T3/T04x hybrids out there.

ive gotten up to like 107ish i think when i had my gt2554r at 15psi. The got me to 12.5afr

Well im looking at 250hp and im afriad with the gt2554r im looking at alot of hot air.

2871r is recommended a few times. Is anyone anywhere actually running one on a Miata?

Just curious as I'm considering upgrading my 2560.

I'm wondering how a 2860 62 trim compares to the DiscoP. Anyone wanna compare the maps?

http://blaastperformance.com/maps/gt28rs-map.jpg

http://blaastperformance.com/maps/gt2860r62-map.jpg

Frank

hmm ok tdo4 15g flows 428 cfm at 2 pr and people have gotten 275 whp out of it 428/275- 1.56*300=466cfm the lb's/min is misleading as it is allrelavent to temperature. FWIW in my calcs 275/.85=323 bhp, and 300/.85= 352 bhp, am i totally wrong And yes you can most certianly reach greater than 100% VE I ballparked of my MS fueling numbers. Cooler denser air can move more and a more effecient combustion all come into play here. Given what has been done i see no problem making 300whp at 2 pr with the right turbo, and setup, on a 1.6 As often as you have said PSI does not matter to noobs and how 10 psi from a tdo4 is different from 10 psi from a t4, i am surprised by your current campaign. But whatever Markp, Y8's and I know absolutley nothing. Hell tell me how MX#3 owners run 20+psi and get maybe 200 whp then hmmm.

I dont care how much a goddamn turbo hweel can output....it doesn't matter.

if 340BHP Requires 37.3 lb/min or 539.71 CFM or X kg/s or X m3/s, you cant change the fact.

the only way to read a compressor map is first determining the amount of volume flow it takes to reach a certain power level, and then determining the amount of boost it will take to reach that amount of voulme per RPM. So you can plot that RPM point on the graph....it's the only way you can do it.

You cant simply say, oh hey my turbo flow X at it's best, so therefore I'll make 700rwhp at 2psi. It's not the way it works.

and lb/min is not misleading, nor is CFM (they are the same damn thing)....it's why the goddamn compressor map has an axis for the volume flow, because it's required to plot against the map.

yes, you can reach over 100% VE, however for the calcs, it's screws up the math completely. Use 100% if anything.

if it's taking these mx3 owners 20psi to reach 200rwhp, then they either have a potato clogging the tailpipe, or are simply using a turbo that's too small.

Not because a small turbo produces less power than the large one, but the small turbo cannot produce enough airflow to support the HP you are asking from it and it's performing well outside the 60% efficiency mark.

Take this chart for example:
http://www.stealth316.com/images/dr-comparo.gif

look at 1.6 DR.

all three turbo will output the same flow at that boost level, where the 9B reaches it's max flow early, the rest of the time the power ouput with the 9B and 15G will be nearly equal.

Talk to Stripes, he used to run a GT2554R and now has a potato on his car, he could give you an actual comparison of the two turbos on the same car. FWIW, last I talked to him, he LOVED the potato compared to the 2554.

Unforutnatly, I think stripes in on vaca, if you talk to him let me know if hes around or checks the boards. I would really appreciate his input.

but looking at those two turbo maps, im not seeing a whole lot of advantage of the GT2860RS. It seems to spool earlier and well top end wont be an issue with either of these turbos.

I agree the potato is more for top end, but I remember him saying that he liked the power delivery of the potato b/c the 2554 ran out of steam high end where as the potato pushed hard to redline. Actually, if 250 is "really" your goal (like it ever ends), I agree with other peeps that 2560 and T3 are probably the better option.

Also, if 250 is really your goal, the 2554 is really stretching it and as you said blowing a lot of hot air. Just for reference, kags old setup with built engine (9:1 pistons) and the better flowing 99 head made ~210-220 at 12-14-ish psi IIRC. I'm not saying that you can't get 250 with the 2554, but it's really stretching the limits of the turbo and you need a pretty efficient setup with minimal IC pressure drop, etc....

Now i just have to figure if I want a china charger or not

Didn't Jason C make 240 at like 9 psi with a 2554? I'd sure like to see all these turbos on the same dyno.

Frank

I believe he did say 240hp @ 10psi on a 99 engine (9.5:1 compression vs. 9:1 compression for NA 1.8), AVO manifold, and a damn good tune. I think stripes made ~220hp at 12-14psi which is more in line with what I have seen elsewhere. Add in a few percent of variablility between dynos and I think they are all in the same ~220 ballpark. Not saying that 250 is not possible, but you are asking a lot of the turbo at that point and blowing a lot of hot air.

I'm checking the boards, I'm just very medicated at the moment:) Yes, I ran a gt2554r and recently switched to the potato. First of all, I really liked the gt25r. It was a blast to drive and put out plenty of power. I think I dyno'd 11psi at around 214hp. I feel if I had time to tune and knew what I was doing, I could have reached 240hp with the gt25r. I came to a cross road with these compression maps just like everyone else. On paper and through these calculations, all of the turbos mentioned above have good characteristics and overlap in your hp goal is some way. For me, I came across a good deal on a potato and decided to try a real world comparison. Most of my findings and results were expected. The potato had more top end power compared to the gt2554r bottom end grunt. Both turbos are fast spooling and fit the miata well in my opinion. It came down to a personal preference and I decided to go with the gt28rs for three reasons:

1) I liked how the gt28rs pulled all with way through the rpm range. I'm willing to sacrifice a little low end torque for more top end power.
2) I can grow with the gt28rs. If I ever decide to build a motor, 300 is within reach with a potato.
3) The gt28rs just feels right. It doesn't feel like it's trying too hard to make hp and it is very drivable. I'm sure there are better turbos for the miata, but I don't have the time or money to test all of them. I guess if I could sum my experience up in one sentence it would be go bigger or go home;) Instant spool is overrated.

Hopefully I'll hit the dyno soon and get you guys some numbers.

I'm tired...going back to bed.

-john

Well said stripes

Attachment 216045 what a difference temperature makes anyway. ;)

Lets hear those opinion boys, and what do you guys think about my future china charger

http://cgi.ebay.com/ebaymotors/GT28R...QQcmdZViewItem

This is a good comparison of how the 2560 and 28RS stack up together.

http://flyinmiata.com/tech/dyno_runs/Jeremy_potato.pdf

IMHO, unless you're shooting for high HP, it's a big scarifice in low-end.

What's your goal, btw?


https://www.miataturbo.net/~web1_bra...hn_stripes.jpg

Internal gate set for 12-17 psi? You want it below what you want to run, so how much boost do you want to run?

Personally I wouldn't pay $400 for a chinacharger. The biggest grip on the chinachargers is the tolerances. Ballbearings just leave that much more room for error.

Frank

250 is where i would like to be, but im used to driving my friends FMII car at 10PSI and I know ill want more than that.

The wastegate, i have a 6-10psi one playing around, and im going to go to ebc eventually

Im thinking the hit for the topend and cheapness is worth, along with the room to grow

the 50 trim just isnt large enough to support the power.

Try the chinacharger....if you dont like, look for a real used 2560 or 28RS or 2871 or something

http://www.squirrelpf.com/turbocalc/...%20%20GT2860RS

will those all work with the manifold and dp setup

Depends on if you get the standard 5 bolt flange on your turbine housings. Are you gonna go internally gated?

yes.

physically, they should all be the exact same.