Bill Reid

iTrader: (14)

Has anbody screwed with bigger turbines... not just bigger A/R. Maybe bigger turbine and adjust A/R from that (?). Trying to keep there compressor mapped to the motor cubes. My 60-1 P Trim is a blast... but obviously its choked up top on my 5.3. I realize the cam also plays a big role. But I have an LS6 cam... and LS6 heads for that matter. I am now wanting to smooth the boost transition as I'm getting tired of transistioning to to PE too easy off the line for normal daily crusing. I am willing to go with something like a 62-1 or maybe a 66... but I would really like to try and somewhat keep the bottom end... even if it is more gradual. I also thought this might be a good discussion because I don't see us talking TRIM that much

dan96z71

I like trim!!!!

But honestly, I would like to get some more details on the difference between P and Q.

TrickTurbo

iTrader: (12)

The only real way to tell is to install and try it on your truck. If you bump you a/r up you will loose a little down low, and gain some up top. Again have to install and see what the truck likes.
And that trial and error stuff gets costly. LOL

Casey2323

iTrader: (14)

P trims can make 700hp ... Whats the A/R ratio on the Hotside? I have a t70 with P trim and .96 hotside... I think its great for a 5.3 but i wanted to drop the Hotside down a few steps and see how it would work... Hotsides = 200.00 brand new and 10min install with the turbo off the truck... Q trim wheel from Turbonetics are 350.00+ and cannot install them youself.. its built,balanced and setup @ turbo shop.. I am going threw the same stuff right now on my own project.. I might try and Max one out just so we can see what a since 70mm P trim can do since i already have a complete kit ... I thought to upgrade turbos or hotpipes and slap another one on the other side..

Mort

I am interested in this as well. I have a T60-1 .81AR on my 6.0L so it must be more choked up top than your 5.3 but I am only shifting at 5600 and it seems to work fine but is the only one I have tried. I have been thinking of trying something a little larger but have no idea what to use. May be a GT67? How does that compare to a 62-1 or to a t70? Time to start doing a little research I guess. My understanding is the P trim is better suited to the STS rear mount. What are the differences between the P and Q trims?

Bill Reid

iTrader: (14)

Here is an example of the T-Series Turbonetics turbine trims. The first number is the exducer bore (exhaust outlet) turbine diameter. The second number is the largest diameter of the turbine where exhaust gasses initially contact it.

P Trim 2.542 / 2.920
Q trim 2.693 / 3.111

So, the Q trim is a little bigger.

Casey, my exhaust A/R right now is .68. I could go up to .96. I saw where Jim (parish) swapped A/R's and judging by the dyno graph it helped up top a little. But that was on a turbo that is the same size as yours on a stock 5.3.

Bill

Casey2323

iTrader: (14)

I called my Turbo guy back and ask him again... I told him your combo... he said your 60-1 is to small for your combo a GT67 even up to 70mm would be Great.. As far as the P trim Vs O trim again... P trim cost 50.00 and any turbo parts dealcarrys them shaft size is common and if you hurt the turbo a 2 day fix... Q trim is for Big Hp 350.00 Alot of machine work to the Shaft,different seal and bearings and work to the Hotside .. Precision Turbo does not sell parts.. If you mess it up then you must send it back to them.. Shipping Bolth ways.. a week or so downtime exotic parts... @ least a 500-600.00 Bill to get you back on the road... With your combo he said you would Gain the same result running the .96hotside on your turbo Vs having a 0 trim installed ( I dont think that was ever your plan ) Do you have a On center turbo On Tangdigital?(SP) I would like to know what you mean when you said ( I am now wanting to smooth the boost transition as I'm getting tired of transistioning to to PE too easy off the line for normal daily crusing)

stock48

iTrader: (16)

Im running a T66 with a .81AR, p wheel on my 6.0 and it seems happy. I wish there was a little less lag, but Im @ 7000' elevation.

Bill Reid

iTrader: (14)

I chose the 60-1 on purpose... for incredible low end torque at the expense of top end power. The 5.3L cam isn't all that helpful up top anyway. 400rwtq at 2500RPM is fun for awhile. But I just switched to a harder compound street tire... so tire fires are almost too easy now. Transistion to boost is crazy quick (transistion to PE)... hence fuel gauge moves to E quicker too. So now, I'm thinking about another turbo with a little more power up top and a slightly longer transistion to full boost from a dig. The LS6 cam (and LS6 heads) may be in the picture for a swap. I was holding off on those because I am going to build a complete LS6 (possibly stroked). I may consider the heads and cam and thats what muddies my waters a bit because I need to either leave the motor alone or commit to swapping heads and cam before I decide on another turbo for the 5.3. I don't know... the truck runs so well now with no problems. Thats usually when I get myself into trouble
So, Turbonetics now offers S Trim (upgraded Q Trim) turbos for their T Series units. Thinking out loud... wondering how a T66 S Trim with a .81 Tang housing would work. Jim (parish) showed in a dyno graph it took a .96 A/R housing to bring the boost-to-back pressure ratio down to about 2:1 if I remember correctly... which is more desirable. So, the thought is to maybe try a little bit bigger turbine wheel and then map an exhaust housing to where I would want the turbo to hit. Figuring if the turbine isn't fighting back pressure so much then the compressor can operate a little more efficiantly. But then again... maybe an S wheel is way too much for anything less than say a T72 or T76. If the option is there maybe the combo could possibly work.

Bill

Casey2323

iTrader: (14)

My truck has a front mount 69.9999999 MM turbo with a P trim .96 A/R ratio 5.3L bone stock 90K with 3.73 gears,detroit,caltrax 3200 stall with 2.1str It will footbrake 2300-2500 but there isnt any load on the engine so cannot even make more then 2psi boost .. Just a few days ago I saw Parish post a dyno sheet going from a .68 to a .96 T70 and P trim wheel... My truck pulls Very well once it gets moving but i dont see a crazy abundace of TQ down low to Fire the tires @ anytime Me and you almost make the same dyno numbers on the exact same engine combos yours with a 60-1 and mine with T70 .... You say yours in super quick to spool and Fun as hell to drive downlow where mine didnt feel like that ( I think the big stall speed had alot to do with that) I say mine isnt so Great from a Dead stop and has a little turbo Lag ... I say leave the Hotside and P trim.. Upgrade the front half so your truck will Pull more Uptop and install your ls6 cam,springs to kill off some off that bottom end... might gain another 40hp and shift everything up 800-1000rpms on the dyno...