Precision Billet Turbo discussion

Nice post. Thanks. Im still worried It will spool too slow for my taste. Especially since I have less RPM's of usable power since my stock heads and cams are done by 6500rpm. If I did headwork and cams and could pull to 7000+ efficiently then I would not be as turned away. Im still lost as to exactly what I want to run. Currently on the top of my list is a HX40 with a 16cm^2 divided housing and a quick spool valve. Measurements of HX40 wheels below, its like a 6064 pretty much lol.

Compressor:
Inducer - 59.84mm
Exducer - 81.76mm

Turbine:
Inducer - 76mm
Exducer - 64.14mm

Note this is the 8 blade compressor wheel. There is a 6, 7, and 8 Blade compressor wheel in the HX40 platforms. The 6 blade flows the most, then 7 blade, then 8 blade flowing the least.

Not trying to stray away from the precision discussion but a little comparitive info on whats out there. Hopefull I can run one of these and get some vids up to see how it spools with a quick spool valve. This turbo is capable of over 500whp and should spool as fast or faster than my hx35, given I run a quick spool valve.

do you realize that a HX40 is going to spool at least 3-400rpm later than a 6262? Not to mention the shafts breaking in them all the time. A HX35 with a small housing would have similar spoolup to the 6262, this is one of the most efficient turbos out there as far as the blend of spool, efficiency and amount of HP capability.

I have a HX35 on my car now and I can tell you it spools quite a bit faster than that 6262 in the video. I get a FULL 17lbs of boost, even in 1st gear before 4000rpm's!!!! An Hx40 will spool a few hundred rpm's slower than that. Put a quick spool valve on it and It should spool as fast or faster than the HX35 I have now does. SATAN threw on a quick spool and picked up 800-900rpm's of spool....

6262 outspools a HX40 on every application i have seen, which isnt that many as HX40s are garbage. 6262DBB outspools hx35 on all 3 of the peoples cars that I know who have done the swap, and made 30-40hp more at the same boost. That video is crap, gives no indication of its true ability. In fact all the buick v6 guys use the 6265 as it spools within 200rpm of the 6262 and makes even more power. Most people that swap the 6265DBB on have replaced the TE44, which is a 60 trim compressor (58mm) stage 3 turbine (the 5857 replaced this turbo) journal bearing units and noted faster spool times as well.

IMHO if you are spending money on a turbo upgrade for fast spool and big power and you dont buy a GT35, 6262 or 6265 in dual ball bearing you should maybe educate yourself more. Those 3 along with the turbonetics DBB TC line, and the Comp Turbo triple ball bearing Ct3b series are the only turbos out that shine

2nd.

Theres no comparison between a billet 6262 and an HX40. billet 6262 > HX40 with quick spool valve.

BB turbo's sometimes have issues with shaft wobble at high boost levels due to their full floating bearing design.

But…z31 owners never run high boost so this probably doesnt apply to most on here.

Can someone point me to PTE compressor maps? I specifically searched for the 5557, 5857, and 6262. Maybe I am an idiot?

I can ask tomorrow at work if we have them saved, no guarantees i'll remember though.

Mike, They aren't out there for the public. I will see what I can dig up for you at work. For 5557 look at ~3427 maps, for 5857 look at ~4476 and 6262 look at ~6152. But the 70% efficiency land will extend much further in pressure ratio and lb/min but start at about the same spots.

Oh, I wanted to add that the 5857 with a .82 turbine housing full boost (23psi) in 2nd is 3800, I am was never looking down when in third or fourth, but I imagine that it was within 100rpm of 3800. When these PTxxxx billet turbos come on, it is like getting shot out of a cannon. If I were to switch to a .63 housing full boost would be about 400 rpm sooner.

http://www.youtube.com/watch?v=7gNJQxG0BbA[/video]]

and the boost/dyno mapping in 4th gear through STOCK axle back exhaust. Light blue line is boost pressure.



Exhaust open…

http://www.youtube.com/watch?v=iqwg44C1wYU[/video]]

Dyno plot open Vs. closed.

define: "high boost levels"

I don't have time right now to address much of what was said and in question, but I would like to reiterate the 3 main things on my car that greatly affect the spool of this turbo.

1. 274 Schneider Cams
2. LOW timing in the mid range
3. 7.8:1 motor

I really can't stress enough I simply did this video to show what I had currently have and experience. Take this with a grain of salt considering my car is not even close to 100%.

all things considered, where do you see it starting to hit full boost by when everything is said and done and it's tuned to your liking?

4400 rpm is a little lazy, but its no question the turbo has much more left in it after the engine's been wrung out to the highest you'll take it.

[quote]Careless wrote:

Originally posted by FlawleZ

I don't have time right now to address much of what was said and in question, but I would like to reiterate the 3 main things on my car that greatly affect the spool of this turbo.

1. 274 Schneider Cams
2. LOW timing in the mid range
3. 7.8:1 motor

I really can't stress enough I simply did this video to show what I had currently have and experience. Take this with a grain of salt considering my car is not even close to 100%.
all things considered, where do you see it starting to hit full boost by when everything is said and done and it's tuned to your liking?

4400 rpm is a little lazy, but its no question the turbo has much more left in it after the engine's been wrung out to the highest you'll take it.

With this 7.8:1 motor, like I said on page 4, I'm confident I can see full boost by ~4000 rpm. Boost comes on even quicker in 3rd and 4th of course but my clutch slips so its pointless.

Also, you guys are aware that my 6262 is a journal bearing 6262, right?

did not even know they were available with a journal bearing.
any reason besides cost? rebuild-ability is cheaper/easier?

Not buying a BB turbo. Cannot afford it. It will be a JOURNAL bearing turbo. So compare to that if you want to compare. And this is what is in the video in this thread, a journal bearing 6262.