stukellymotorsports

Hey guys I am after the fastest spooling turbo which will make AT MOST 750-800hp with a max of 20psi.

My setup is a Stock 5.3L L33 with boost accommodating strength mods.

I just sold a Borg Warner s475 T6 because it was too laggy for me, and now I am looking for something that spools much quicker but will make less power overall.

I have been reading around the forums trying to find dyno sheets and answers to this, but most of these turbo ls setups are for drag racing, and include automatic transmission spool vs traction information that I do not care about.

I am looking for the earliest rpm tire spinning (SINGLE) turbo, that is $1700 or under.

My main choice right now is the PT6766 1.32A/r T4 Divided Ball Bearing, but I am still very open to other ideas and options.


Here is what I did this year on the S475 T6

Forcefed86

iTrader: (4)

Any pics of your hotside/coldside design? What diameter pipes did you use? A ton of response can be picked up using smaller piping than many consider optimal. In your case 2" piping off each manifold going to either side of a t4 scroll and kept divided. Then using 2.5" coldside piping.


I'd go with the 11 blade S366 with the .88 T4 housing if you wanted instant spool. It will meet your goals and light off quick. Sturdier unit than the precision based turbos IMO and costs much less.

http://www.smedingdiesel.com/product-p/bws366.htm

If this is your hotside/coldside on a 5.3 liter thats alot of your problem IMO.

stukellymotorsports

I used 2.5" diam pipes on the t6 setup, but I will be redoing the whole manifold for a new t4 turbo regardless.

and Yes i had read alot of not so good reviews across all motor platforms of precision failures which is also why I am still open to other ideas. The borg warner does seem like a very stout (heavy) unit and are probrably cheaper to rebuild.

What made you choose the .88 housing on that BW vs the .91 Divided? To my knowledge the divided housings spool faster but may flow slightly less.

Forcefed86

iTrader: (4)

Sorry, I mis-read it... When they said "standard housing" I was assuming they meant undivided. Def go divided. With a 370" motor I'm using 2" divided hotside. One bank to each side of the T4 scroll. Each with it's own 38mm WG. The difference between this setup and the previous years 2.5" merge style hotside was night/day. I also data log back pressure and the 2" divided hotside is making slightly less back pressure than the old 2.5". Should also note the old 2.5" setup was on a 5.3.

When your on and off the throttle constantly in a drift car I'd want the 360* thrust bearing as well.

Also FWIW for a twin scroll setup to work properly you need to divide the exhaust pulses from bank to bank. Because of the firing order on a typical V8. There is no simple way to do this easily. There is very little gain in using a twin scroll VS an open scroll housing IMO, but every little bit helps. Was also easier to fabricate than making/buying a good merge and keeps the exh gas at a more constant velocity.

stukellymotorsports

I was also looking at the GT4088R turbo as an option.

ben husen

id think a s366 is a lil on the small side
go with like a s472 and go a smaller exhaust housing like a t4 1.1 ar
also i see no talk of cam that can make a huge difference also go talk to ljms

Forcefed86

iTrader: (4)

The billet S366 I liked to puts out 86lb/min of air. More than enough for his goals and it will spool much faster than the S472.

coltboostin

Thats good to know. Your ona 6.0 now correct? And larger turbine?

Did you get a chance to test same motor/turbo with new hot pipes?

Forcefed86

iTrader: (4)

.030 over 6.0 yup. I had the same turbo on the old 5.3 initially before upgrading to the larger wheel. Back pressure only dropped slightly with the larger wheel in the same 1.25 housing.

anheuserbusch08

iTrader: (11)

S475 83 1.10 with race cover and a billet wheel

stevieturbo

http://www.agpturbo.com/borg-warner-...3-13009097051/

69mm SXE

That said, the 6766 would probably work too....just not sure how much faith you'd put in it being reliable.

A T6 and with 2.5" pipes was always going to be laggy !

stukellymotorsports

What do you all think the spool difference between the s366 and the 6766 would be. Is it worth the extra $1000 and possible reliability issues?

mkvamso

iTrader: (2)

Ive been beating the **** out of my 7675 without issue, i dont think the precision reliability issues are as bad as people make it out to be.
The ones with issues usually let everyone known about it. not saying people havent had failures, but its not like your guaranteed to have the turbo come apart.

That being said the bw will probably make a little more power, wont run out of breath quite as fast as the precision, and its much cheaper

The precision is easier to package, should make very close to the same power as the borg, and spool faster.

gnx7

iTrader: (28)

That's a bad *** little FC!

What trans/clutch rear end/gearing?

rotary1307cc

iTrader: (5)

Sxe 69

Forcefed86

iTrader: (4)

What is better about the SXE69? Has the same exh wheels as the 66 I posted. Has a 66mm compressor (is that a typo in the ad?) And costs a ton more. $1157 with T4 housing.

The 11 blade 66 flows 86lb/min. (Plenty for his goals), and comes with the exh housing for $855. Also the 11 blade units are suppose to spool more quickly.

rotary1307cc

iTrader: (5)

Because look at the compressor maps

Quoting peak max flow means nothing, as you will never even get near that section of the map in single configuration with the v8

The 69 is skewed farther to the right at the lower pressure ratios he will use, hence better suited for his application. And for an honest 750whp

The 69 will spool stupid as is so I don't see the argument.

Had twin old cast 66s and swapped to the new 69s and on the dyno overlay there is zero difference in spool between the two, just alot more power

rotary1307cc

iTrader: (5)

And you can get the 69 for under 1k, give away compared to the pte junk

Forcefed86

iTrader: (4)

Argument would be price VS performance. If he can reach his goal for less money I’d go that route personally.

I don’t claim to know how quickly either will “spool”. Though without a side by side comparison, I don’t’ see how anyone can claim the SXE spools faster or slower than the 11-blade 66 (or which makes more power). I don’t know of anyone running an 11-blade unit, or of a compressor map for one? They use the same exh. wheel and housing so the difference is all in the comp wheel, no? I doubt the 2 would spool “the same”. I know the OldGold guy had the billet 66 6-blade .91 S366 on his “cam only SBE” 5.3 and made 650whp at 14lbs and 13* timing. He later ran 20 on the street claiming it never fell off power wise. No track numbers though so who knows…

rotary1307cc

iTrader: (5)

I just know for what he wants that is what I would run, and it is cheap even at 1100 compared to the pte junk

And splitting hairs on spool, either of the Borg 300s with the 73/80 no matter the compressor are going to be a light switch

Here is dyno overlay.... 80e car locked... One with the standard sx3 66, 73/80-.88

And the other with nothing else changed the sxe 69 73/80-.88

Reds are engine rpm. Blue are trans input shaft speed

Can see the response is identical. But the converter let's go on the 69s because it can't couple the extra TQ



He said best, not cheapest