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There is a mistake in the PET for the turbo reservoir O-ring. If you order the part that's specified in PET you will get a crush washer. You actually want a 999-701-598-40 O-ring.
Thank you Sir; I am going to start a book on the parts change from the PET - as I recall, this is the second mistake in the PET, the first being that silly 11mm snap clip on the coolant line that is listed as a 10mm and kept blowing up on me.
at what point do rods become an issue? or is it all in the tuning to limit tq down low..
Torque is what kills rods, not HP. Rods will be an issue past much more than 600 ft.lbs in my opinion. That is the reason that K16 billets or the small frame Xonas make very little sense as they can develop 700 ftlbs down low and fizzle up top. With a small frame turbo you end up detuning the low end protect the rods and still have little from mid range on up. The larger frame Xonas spool up in a much more linear fashion keeping tq in check down low while allowing hp to build with rpm. Below are two graphs, first is a K16 billet on a 3.8L and the second the XR980 on a 4.0L. Both are at 1.3bar on 91 octane, same exact dyno. Which one is easier on the rods? Do you want an engine that falls on it's face past midrange or do you want one that keep going to redline?
Torque is what kills rods, not HP. Rods will be an issue past much more than 600 ft.lbs in my opinion. That is the reason that K16 billets or the small frame Xonas make very little sense as they can develop 700 ftlbs down low and fizzle up top. With a small frame turbo you end up detuning the low end protect the rods and still have little from mid range on up. The larger frame Xonas spool up in a much more linear fashion keeping tq in check down low while allowing hp to build with rpm. Below are two graphs, first is a K16 billet on a 3.8L and the second the XR980 on a 4.0L. Both are at 1.3bar on 91 octane, same exact dyno. Which one is easier on the rods? Do you want an engine that falls on it's face past midrange or do you want one that keep going to redline?
K16 hybrid on 3.8L
XR980 on 4.0L
And, just had to flick through those pics again - stunning level of detail and engineering.
Torque is what kills rods, not HP. Rods will be an issue past much more than 600 ft.lbs in my opinion. That is the reason that K16 billets or the small frame Xonas make very little sense as they can develop 700 ftlbs down low and fizzle up top. With a small frame turbo you end up detuning the low end protect the rods and still have little from mid range on up. The larger frame Xonas spool up in a much more linear fashion keeping tq in check down low while allowing hp to build with rpm. Below are two graphs, first is a K16 billet on a 3.8L and the second the XR980 on a 4.0L. Both are at 1.3bar on 91 octane, same exact dyno. Which one is easier on the rods? Do you want an engine that falls on it's face past midrange or do you want one that keep going to redline?
K16 hybrid on 3.8L
XR980 on 4.0L
sorry for all the questions... the wealth of knowledge on this board is amazing... i'm trying to figure out the direction i want to go...
my car is strictly a street driven car and will never see a track or road course... do you think it's still worth the step up into a bigger turbo without the down low grunt for the street? i was leaning towards the responsiveness of the k16 billet since i'm not sure there are many roads where i can utilize the top end of a k24 billet... xonas are pretty though... dammit...
I was going to do the rezs so that I had two complete sets, one for each pair of turbos - oil lines and ancillaries to support the upgrade just seems like a good, preventative maintenance step (along with the o rings) as they have been on the car for 18 years. Those IDC 1300 injectors, if I am not mistaken, are 1300cc units. I have the Radium/Walboro fuel pump, along with the Bosch MS 5.0 bar FPR - I think I have enough fuel (with injectors of course), however, I do like the idea of running a slightly larger fuel line to support demand.
As you can see from the pic below, I was planning on running John's (Speedtech) 50 cell cats, however, the mating flange is only 75mm ID, and, it looks like the way he built the cats was to sleeve the flange then weld the flange to the sleeve. I'll need to make up another set in order to get to 89mm as it may be very tight to Dremel off the lip and machine the flange in order to reach almost another 1/2", so that may not be the most reliable approach. I am not sure if John made your 3.5" test pipes, but I will ask you for direction on where to go to get these/this done. Compressor surge does not appeal to me.
To further reliability, I am not planning on running higher than .8/9 bar - the same pressure as a stock X50, but with considerably more flow. To my way of thinking, this is ideal as I recall you were seeing 580WHP at this pressure, which would loosely translate into 650 FWHP - a little more than target, but I can live with that as I am not over pressurizing the intake plumbing. Your numbers at 1.3 bar are very desirable to me, but not until I do something with rods and pistons, at the very least. I am very keen on smooth, linear power delivery, so the logic behind the WG setup makes a whole lot of sense to me. On my STI, I am running a Tial external WG with a 1.0 bar WG spring, and an HKS step motor boost controller that ramps up the boost to 1.5 bar; it does hit very hard - and perhaps, not the smoothest, but entertaining. I think the turbo should be a little more refined, so I will leave it as you have configured it.
I can also tell that a considerable amount of effort has gone into setting these up for your car, and as such, I have decided that I will not coat them as this will require them to be taken apart and reassembled, and I am not skilled enough to put them back together in the same manner.
Still, very exciting, and cannot wait to run them!
The rubber O-rings for the reservoirs are 999.701.598.40. They are labeled wrong in PET. Yes, the IDC1300 injectors are 1300cc. You do not want or need to run a 5.0 bar FPR. Use the OEM 3.8bar regulator. We use the adjustable 3.8 Bosch Motorsport FPR but that requires full fuel pressure logging capability to set up so I would recommend the OEM 3.8 FPR.
You will need a larger flange and cat/bypass pipe. We use a 3.5" which works out to 89mm ID. John at Speedtech is familiar with what is required. From a set up perspective on the Turbos, you should be ready to go. It took a lot of experimentation to get the set up just right as the turbos come from the factory preset to run much higher boost. We also had to clock the housings to the proper orientation for optimal tire clearances. It's all set for you. I would not coat the turbos if I were you.
Thank you John, I will reach out to other John and get the ball rolling. I saw the time involved setting them up, so no I will not be taking them apart to coat them.
sorry for all the questions... the wealth of knowledge on this board is amazing... i'm trying to figure out the direction i want to go...
my car is strictly a street driven car and will never see a track or road course... do you think it's still worth the step up into a bigger turbo without the down low grunt for the street? i was leaning towards the responsiveness of the k16 billet since i'm not sure there are many roads where i can utilize the top end of a k24 billet... xonas are pretty though... dammit...
For a tiptronic car which would clearly be a street car, the small frame turbo would make sense as the car is mainly operated at low rpms with the auto box. If you have a manual, you choose which rpm you want to operate in. No one says you can't wind out the engine in 2nd, 3rd or 4th to get the performance out of it. That's what makes a GT3 so much fun. Running a set up that fizzles out at 5K rpm with 2.5K more to go is akin to going to a party at the Playboy mansion and going home 3hrs before the party ends...
Last edited by powdrhound; 09-15-2021 at 07:37 PM.
09-15-2021, 10:23 AM
