[Robert]

Originally Posted by wdodge45

Robert,
Greg said the wheels were a P trim and no wheels r available anymore due to these being older style??? Hard to believe no wheels for such a popular turbo?
So, where do we go from here.....GT-K 550, 650 or new style TN 62-1??? This does create more issues sooooooooo, looking for ur help here.
Thanks,
Bill

Well he is correct the P trim wheel was dicontinued and replaced with the F1-62 wheel. I'm double checking it with the manager but I'm fairly certain you could upgrade the turbine wheels to the newer F1-62 with the same bearing housing but at that point a new turbo wouldn't be a bad idea anyways. A GT-K 650 isn't a bad idea at all actually. The GT-K 650 uses an HP66 compressor wheel with a peak flow of 72 lb/min of air. The 62-1 produces about 65 lb/min of air and the 60-1 produces a max of 57 lb/min of air. VERY VERY VERY generally speaking you make about 10 HP per lb/min of air. Before anyone jumps down my throat on that its a very very rough guideline to start with and then adjust dependent on the characteristics of the motor and system design. So to put things in perspective you were making about 1200-1300 HP with two turbos that would produce a generalized 1040 HP of air. The 62-1s would have taking you to 1300 HP of air (the 200 HP difference we were looking to get to). The HP66 compressor wheel from the GT-K 650 takes that to 1420 HP of air.

What does that mean to you? The GT-K 650 will meet your goal of 1500 HP and have headroom to spare with ZERO issues. The other nice thing about the GT-K 650 is the newer F1 turbine wheels flow more air than any previous model turbine wheel (like the old P trims) and still get you spooled up FASTER than the older turbine wheels. The other very positive point for the GT-K 650 is the ported compressor shroud. By porting the compressor inlet shroud the air can bypass the inducer a bit at lower boost pressure and will actually increase the compressors efficiency at lower engine speeds. That means more power at the bottom end by just porting than shroud then you would have not doing it.

If new turbos are in the cards the GT-K 650s are a GREAT choice for your application. The boost curve IS going to change. Your car will spool up a little bit different then it used to with the 60-1s you used to have but it should be for the better. You should actually spool up a bit faster and make MORE power an the bottom end the you ever did. Plus you will have the 1500 HP you are looking for to go with it.

[wdodge45]

Robert,
Well decisions decisions.... What is ur take on the GT_K 550's, u previously said they would outflow the the 62-1's. My biggest concern with any change is spool time, I don't want to lose what I have but at the same time realize I have some options. I do like the headroom on the 650's but concerns on being able to spool them like the 60-1's without making any cam changes and such. We went to the 1.30 AR housing to bleed off some boost but wanted to remove as much back pressure as possible. If the decision to go bigger I think the AR will change drastically to a much smaller AR. Your professional opinion is greatly needed and I don't want to be irrational or hasty about the turbo's I end up going with.
So here's ur chance to hook a brother up......LOL

Thanks,
Bill

[Robert]

Originally Posted by wdodge45

Robert,
Well decisions decisions.... What is ur take on the GT_K 550's, u previously said they would outflow the the 62-1's. My biggest concern with any change is spool time, I don't want to lose what I have but at the same time realize I have some options. I do like the headroom on the 650's but concerns on being able to spool them like the 60-1's without making any cam changes and such. We went to the 1.30 AR housing to bleed off some boost but wanted to remove as much back pressure as possible. If the decision to go bigger I think the AR will change drastically to a much smaller AR. Your professional opinion is greatly needed and I don't want to be irrational or hasty about the turbo's I end up going with.
So here's ur chance to hook a brother up......LOL

Thanks,
Bill

Bill,
I completely understand. To be honest I was under the impression you were running T3 turbines on your current units. With that big of an A/R It just seemed like you were. If you were in fact running P trim turbines the F1-65 (P trim F1 turbine wheel equivalent) should actually flow more and spool faster even with the exact same A/R housing on there. You might actually be able to go a little smaller on A/R as the new F1 wheels physically flow more (less backpressure) than the P trim wheels they replaced. You could probably go to .96 A/R housings if you wanted to with the new wheels or you could stick with the 1.30 A/R as you know it well. Believe it or not your spool up shouldn't be too much slower. The larger compressor wheel will obviously spool up slower than the 62-1 or 60-1 but that is straight physics. The larger wheel is heavier. The thing that negates a lot of that is the new F1 wheel. It's taller tip height alone would have made your current turbos spool up even faster than they do now so that benefit will help reduce any additional lag you might find with the HP66. I say that with a grain of salt as we aren't talking 1000 RPM difference in spool up here. Maybe 100-200 RPM difference with the F1 wheel and the larger compressor. The GTK61 compressor wheel (compressor wheel used on the GT-K 550) does flow more than the original 60 series. It will be close to the 62-1 in terms of flow potential though. It should outflow it by just a few lb/min. If you were using P trim turbines before you'd have to do something custom though as there are no GT-K turbos with a GTK61 compressor and F1-65 turbine wheel.

Phew, let me take a step back from the nitty gritty tech stuff. Bottom line, if what you had before was a 60-1 compressor and a T4 P Trim turbine wheel with a 1.30 A/R you will NOT be disappointed with the GT-K 650. The 650 will give you the power you want today, the head room you may want tomorrow (or next year, etc) and a lot of great features like increased power at the bottom end and a wider more efficient compressor map. Your boost curve is going to change. There's nothing that can be done for that. Even if you went with the GT-K 550s it would change. The GTK61 compressor is different than the 60-1 or 62-1. Like I previously posted the 60 series compressors had a very unique type of boost response and compressor map. Any other compressor wheel is going to be different no matter how you slice it. But the bottom line is the HP66 is not a bad option here. In fact its a VERY POPULAR option for twin turbo LS applications trying to make this kind of power. While the boost curve is going to be different you may find you like it even more. The HP66 can flow more and flow to higher pressure ratios within the compressor efficiency island. The F1 turbines should keep the spool up VERY similar. With the amount of displacement you have and the design of the F1 wheels your boost curve may change but it won't be something incredibly dramatic. You will see it on a chart but whether or not you feel it on the butt dyno I can't say. Honestly, if new turbos are the final answer for your car the GT-K 650s is the way I would go.

[Robert]

For reference here's a thread of a guy on a SBC running HP66 compressors (whats in the GT-K 650)

http://turboneticsinc.com/forum/turb...altered-2.html

[Robert]

His runs in the 1.4 mile info with 66mm compressors. Look at the 1.8 mile time. Not a whole lot of lag there:
went<
7.4 @ 186.2
7.11 @ 186.4
7.04 @ 186.1

last run figures:
1.039 60 ft
2.8 330ft
4.4 @ 155.2

19 psi ( single stage boost only turned on , 28 psi 2nd stage to come ) twin turbonetics BB 66mm , 358 sbc

[wdodge45]

Robert,
U out did urself again....the info is very helpful and I hear what ur saying about the GT-K 550's...so...my only concern will be that I have on center housings and must stay with that as that was how the car was built (my pics I sent u shows the setup). Will these turbos fit the same basic way as my on center 60-1's do???
Thanks for all the info, may have a few more just prior to ordering the new turbos....Sorry for all the questions, just want the car right....faster with good driveablity, what else could I want.....LOL

Thanks again for all the professional help and tech,
Bill

[Robert]

Originally Posted by wdodge45

Robert,
U out did urself again....the info is very helpful and I hear what ur saying about the GT-K 550's...so...my only concern will be that I have on center housings and must stay with that as that was how the car was built (my pics I sent u shows the setup). Will these turbos fit the same basic way as my on center 60-1's do???
Thanks for all the info, may have a few more just prior to ordering the new turbos....Sorry for all the questions, just want the car right....faster with good driveablity, what else could I want.....LOL

Thanks again for all the professional help and tech,
Bill

Bill,
The default part number comes with a tangential turbine housing but there are on center turbine housings available absolutely. I'm looking at the parts list right now and there is a F1-65 turbine housing, on center, 1.30 A/R available. Part number is 21609-65. (1.30 F1-65 ON CENTER 21609-65). You would just make sure you specify that you want the on center housing when you order the GT-K 650s and it shouldn't be an issue. Glad I could keep helping out. I can't wait to see how you like the turbos and see some video of the front end up charging up Oldsmobile. The compressor inlet of the GT-K 650 is a 4" in and 2.5" compressor outlet. This should be exactly the same as the inlet and outlet you had on your 60-1 full size. The actual dimensions of the compressor housing are larger on the GT-K 650:

GT-K 650 compressor housing dimensions: http://www.turboneticsinc.com/sites/...RIES_TURBO.pdf

60-1 compressor housing dimensions:

http://www.turboneticsinc.com/sites/...RIES_TURBO.pdf


So the compressor housing is larger but not by a whole lot and the inlet and outlet dimensions should be identical.

[wdodge45]

Great news....the reason for the 1.30 AR was we were overboosting with the .96 housing that was ordered originally and we where flat on the upper rpm, the 1.30's made all the differance in the world. It took care of the overboost by bleeding some air and it also helped with the restriction too, the car woke up and was totally like driving a new car with way more HP.
So, will we hurt ourselves here by running the bigger AR or should we drop it down? Or just leave it alone?
Paul Traci's car went with HP66's and they had to re-cam to help spool the turbos faster as they weren't spooling until 4k, but he also doesn't have the GT-K 650's either, and what I'm hearing is the way the compressor is ported on the GT-K 650's and the new wheels this shouldn't pose the isssues Paul is having...yes/no?????
Bill

[Robert]

Originally Posted by wdodge45

Great news....the reason for the 1.30 AR was we were overboosting with the .96 housing that was ordered originally and we where flat on the upper rpm, the 1.30's made all the differance in the world. It took care of the overboost by bleeding some air and it also helped with the restriction too, the car woke up and was totally like driving a new car with way more HP.
So, will we hurt ourselves here by running the bigger AR or should we drop it down? Or just leave it alone?
Paul Traci's car went with HP66's and they had to re-cam to help spool the turbos faster as they weren't spooling until 4k, but he also doesn't have the GT-K 650's either, and what I'm hearing is the way the compressor is ported on the GT-K 650's and the new wheels this shouldn't pose the isssues Paul is having...yes/no?????
Bill

One question, did Paul's car have the newer F1 turbine wheel? That would have made a big difference as well. Of course we won't know 100% for sure how your car will do with a smaller turbine housing like a .96 until the car is under load on the dyno. If Paul has the same exact motor setup as you and had the F1 turbine wheels and a 1.30 A/R housing and he had to re-cam to lower the spool up time then yes a .96 would speed that up. I'm just leary of the issue you hit before. I don't want you to be flat up top either. Honestly for me its a 50/50 toss up with the A/R just because I don't know if Paul's car and your car are apples to apples. You are correct about the compressor housing ports though. The ported compressor shroud allows some air to bypass the inducer under lower pressure ratio operation which will make the compressor more efficient at lower boost pressure than without it. It will also help get the turbo up to full boost a bit faster for the same reason. Whether or not this will completely make it the same as it was before again I don't think anyone can say for sure until the engine is under load. If you know which turbine wheels Paul was running I could help estimate a little better of course. If Paul doesn't have the F1 turbine wheels or compressor shroud porting then no you should not have to worry about re-camming the car for these units to spool up. It will change spool up time just a bit but like I said before it shouldn't be more than a 100-200 RPM difference. If you ran P trims before with a 1.30 A/R I would stick with the 1.30 A/R housings now. The newer wheels spool up better then the old ones will in the same exact housing. The real question, will the improvement in spool up from the new turbine wheels completely offset the impact of running a larger compressor wheel. My honest answer is it will be very close. With the ported compressor shroud added to the equation to the race is going to be even tighter but I think you'll be ok.

[wdodge45]

Great Robert....looks like GT-K 650's r the way too go....thanks so much for the effort and time put out to help get me close to my goal and potential for more...LOL like I need more....HP is like crack....u just always want more...LOL Bad Comparison I know but funny...
Hopefully the GT-K 650's won't let me down..as far as Paul Traci's set up, i will find out all the details and shot them back to u tomorrow and lets see how close r setups like and if we r close or better.
Thanks again,
Bill