turbo upgrade - pauer tuning

[nize]

i thought i'd write a review on my recent custom turbo upgrade.

the turbo upgrade i was looking for had to meet these very difficult qualifications;
1) fastest spool possible, must spool like the stock turbo-s turbocharger. i was not willing to sacrifice lag for power. i was looking for 18psi by 3krpm with no dropoff to redline.
2) be able to support 350whp.
3) be plug-and-play. i wasn't willing to jump through hoops and hunt down special nuts and bolts and clamps and adapters for a turbo swap.
4) the vendor must be willing to communicate with me about exactly what i was paying for. sadly, this dropped vitesse off the list as i wasn't able to get any detailed specs regarding their turbo for a meaningful comparison. i would love to see a back-to-back vitesse turbo review with dyno graphs.

after much research, debate, and discussions, i decided what i was looking for was a garrett dual ball bearing center cartridge with a 50-trim compressor and #10 hot side. fortunately for 951 owners, there are many porsche specialists to choose from when considering a turbo upgrade, and many more choices of turbochargers. unfortunately and understandably, most vendors will not tell you the exact specifications of their turbos for fear of copy-cat vendors stealing their designs. following is a list of the vendors i considered during my turbo hunt, and the reasons why i did not choose to go with them. they are not in any particular order.

vitesse stage2;
this was actually my original first choice. although i have heard great testimony regarding their turbochargers, i could get no technical information regarding what exactly i would be buying. this combined with no concrete before and after dyno graphs plus the extremely high price (they were by far the most expensive) made me choose to seek a different vendor. i believe if i'm paying premium for something, i should know exactly what i'm paying premium for.
http://www.vitesseracing.com/html/turbo.html

ultimate motorwerks;
this is a vendor local to me and i have heard great things about their 'zero clearance' turbos, but i have also heard that they need to be rebuilt often because they coat the inside of the compressor housing with some material to get the 'zero clearance'. i wanted more reliability and less maintenance so i looked elsewhere. there is also no technical information regarding these turbos.
http://www.ultimatemotorwerks.com/

innovate motorsports; (no longer in business)
i sent an email but got no response. their website also does not contain any information regarding their turbo product(s).
http://imsmotorsports.com/

edit 12/06/2007: it seems the ims website has been hacked, and/or the company is no longer around. if anyone has info, please let me know.

034 motorsport;
this is actually the least expensive vendor as far as listed price is concerned. the only concern i had was that they were unable to provide 951-specific support or advice so i had a feeling i would be on my own as far as special adapters, oil lines, and fittings were concerned. for the true do-it-yourselfer, this may be the most cost-effective route.
http://www.034motorsport.com/product_info.php?products_id=107&osCsid=365d6f5572 62fc84dd8f26063501ba33

john milledge engineering; (no longer in business)
this is another vendor with a legendary reputation in the 951 world so i naturally sent him an email with my initial request. he replied to the first email stating that the group-a type turbo was no longer available and that my target goals were unattainable, then failed to reply to repeated emails asking for more information. i got the impression he was a difficult person to deal with and unwilling to work with customers. or maybe i just got him during a bad week.
http://www.jmengines.com/index.htm

edit 10/24/2007: it seems john millege shut down. it's always sad to see a longtime 951 specialist close shop. it could also explain why he wasn't enthusiastic about selling me a turbo. good luck john!

edit 8/11/2014: john millege is back with a new website: http://jonmilledgeengineering.com/Home_Page.html

lindsey racing;
what i love about lindsey racing is that they give you all of the information you might ever want regarding their products. what i don't love is that all of their turbos are oldskool journal+thrust bearings with crazy lag and that no ball bearing turbos are available. who cares if you're making 400hp if you have to wait until 5000rpm for full boost? dave should get with the times and stock some dual ball bearing turbos.
http://www.lindseyracing.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=LR&Category_Co de=944TURBOSSUPER

edit 10/24/2007: it seems lindsey is now (finally) offerring true garrett dbb turbochargers. it's about time, dave! lindsey does not have the stock turbo water-pipe mod available. this means it would be up to the customer to come up with their own coolant plumbing, which is a difficult task that requires custom welding. this is stated on their web site: Customer will be requried to adapt their water and oil connections.

speed force racing;
this is another vendor with a great reputation. unfortunately, i do not have any firsthand experiences with sfr. they may be another great source for garrett dual ball bearing turbochargers for the 951.
http://www.speedforceracing.com/productsporsche_turbochargers.php

pauer tuning;
vic at pauer tuning was not only very prompt to my initial emails, he was also forthcoming with information regarding turbochargers in general and why i should choose his product (or not). he was also willing to beat any competitor pricing and provide after-sale support and installation advice. throughout the entire initial exchange, i kept thinking 'now here's a vendor who really knows how to treat potential customers and is as excited about 951's as i am' so i chose to go with him.
http://www.pauertuning.com/turbos.htm

i should also mention that i have three local 951 friends who are also in the market for a turbo upgrade and they were all eagerly awaiting my research and legwork so they could copy my results and purchase. i didn't mention this to any of the vendors up front because i wanted to see how my single purchase went. by the time i placed my order, one other local 951 buddy also ordered the identical turbo from pauer tuning so vic got a double sale. two other local 951 guys will be ordering their turbos from pauer tuning as soon as they see my dyno results.

note to vendors: treat your potential customers right, because they have friends !

this is a photo of the new turbo next to the old turbo;


and a side-by-side shot;


this is a video of the fully assembled turbo being blown by mouth on the hot side. it spins very easily;
http://www.youtube.com/watch?v=Ry5dTFg3RSM

components needed for a hassle-free plug-and-play turbo swap from pauer tuning, all are available from pauer tuning;
-the turbo itself
-modified oil line and related components (different sized holes/threads for the oil feed)
-modified water pipe and related components (different sized holes/threads for the water, and the stock water pipes will not clear the larger aftermarket compressor housing)
-aluminum plate for mounting gasket (aftermarket turbo does not fit perfectly over stock rubber o-ring seal)

additional component needed, this is NOT available from pauer tuning;
-if you are using the stock intake system like i am, you will need some type of mod to get the stock j-boot to fit the bigger 3" compressor inlet. i used a piece of pvc plumbing pipe with a 30-degree bend and a rubber no-hub coupler, which cost around $5 total at home depot. i would recommend the lindsey j-boot adapter, which is what i have ordered and will be switching to for a cleaner install;
http://tinyurl.com/jboot
edit: check the bottom of this post for the j-boot adapter mod!

potential problems that may prevent true plug-and-play;
1) the plastic cover on the back of the alternator needs to be modified, as the location where the electrical wire enters the cover will prevent the larger inlet of the cold housing from clearing whatever intake adapter you connect to the turbo (see photo). this is a very easy mod and it would seem that any larger diameter (ie; bigger) turbo inlet would require this to be altered.





2) depending on the orientation of the cold side housing, the installer will possibly need to grind the top of the turbo compressor housing down about 1/8 inch to accommodate the bottom of the intake manifold (see photo). i had to do this to make mine fit. it was relatively easy to do this using a dremel with a grinding stone attached. you'll have to be careful not to get aluminum dust into critical areas on your motor, and wear a mask to prevent breathing aluminum dust.



3) depending on the orientation of the cold side housing, the installer will possibly need to grind down one of the bolts at the bottom of the turbo holding the cold housing to the center section (see photo), because this bolt may not clear the bottom of the turbo mount and prevent proper mounting. i was lucky and did not have to do this, but i have heard that some people just remove this one bolt and keep it removed to simplify installation.

[nize]

...continued:

some gripes;
1) it seems the metal clamps holding the hot side housing to the center section is plated with chrome or some other material, and this plating will flake off and peel after the turbo heat-cycles a few times. this isn't a big deal, but does make it appear as if the part is cheaply manufactured. i would recommend using non-plated clamps, or using a sander to remove the plating before installing if you don't want chrome flakes later. this isn't a huge deal but worth mentioning.
2) the center section exterior will rust when exposed to water. again, not a problem but worth mentioning.

some praise;
1) as far as i can tell, this is a substantially larger turbo than the stock k26/8 that comes with the turbo-s model, but still manages to spool exactly the same as the stock turbo. using a standalone wolf3d ems with custom boost control, i was able to achieve 1bar (14.5psi) of boost with this turbo by 2800rpm, which is identical to the stock k26/8 turbo. the difference is that this turbo will easily hold that boost to redline. even when i tried turning the boost up to 18psi, and then 21psi, this turbo will not run out of breath like the stock turbo does. i do not have the mods in place to support higher boost, so i haven't tried anything higher than 21psi, though i'm certain that it will easily hold at least 25psi to redline, as i've seen boost creep and had to turn my boost settings down.
2) transitional boost, which is the boost recovery phase between shifts, is something that is rarely discussed in turbo reviews but i feel is important. the transitional boost with this turbo is much faster than the stock turbo. this is something that you'll immediately feel and notice.
3) vic at pauer tuning is a nice guy and is eager to go out of his way to help you. customer service and after-sale support is so far the best i have ever had with any vendor at any price.

overall, i am happy with this turbo upgrade so far.

you can read my entire story that led to this turbo upgrade here;
http://forums.rennlist.com/rennforums/showthread.php?t=342418&page=1&pp=40

i will update this post with new information and dyno charts as soon as they become available.

[87944turbo]

Excellent Thread! Thanks for taking the time to document your experience and share it with us!!

[soxnail]

Nice job Nize, I have been looking too..
Sox

[nize]

edit addendum: here is a side-by-side comparison between the new turbo and the stock turbo;
these side-by-side turbo vs. turbo comparisons were performed on the same car with the same mods and the same tune. the only thing that changed was the turbocharger alone.

(note that 1bar=14.5psi)

stock turbo-s k26/8: 15.2psi at 2797rpm


50trim dual ball bearing turbo: 15.7psi at 2938rpm


stock turbo-s k26/8: 18.6psi at 2938rpm


50trim dual ball bearing turbo: 18.1psi at 3063rpm

[Lawrence Coppari]

Hey Nize,

I'm having trouble reading the charts you posted. The ordinate on the left is engine rpm. What are the ordinates on the right for each of the three graphs? The abyscissa is time implying the 50 trim spools much faster. Is this correct? Thanks.

[nize]

engine rpm - boost
air/fuel ratio - injector duty cycle
engine load - throttle position

the top is time.

the 50trim spools faster, and holds boost past redline without dropping, even though it's a much larger turbo.

[Lawrence Coppari]

Thanks for the useful information.

[nize]

edit: addendum
i've figured out a better way to demonstrate the difference in spoolup speed between the stock and the dbb turbo, i've timed between when the turbo first begins to build boost, to when it reaches maximum boost. this demonstrates the differences in the amount of 'kick in the butt' aspects between the two;

stock k26/8 takes 14.4 seconds from 0psi to 20psi;


50trim dual ball bearing takes 8.3 seconds from 0psi to 20psi;

[nize]

update on the j-boot mod from lindsey. here's my before hack job where i used a 2" to 3" plumbing no-hub coupler connected to a 30-degree pvc elbow pipe that i sawed off;


here's the lindsey j-boot adapter using a metal pipe;


i've heard some people had trouble getting it to fit properly, so i made a how-to. the easiest way to get a straight cut is to first trace the cut line, and then make the actual cut. i used a box cutting razor blade;




after it's cut off, you'll need to shave the four ribs off;


for some reason, lindsey's angle at the pipe weld is too big, so it doesn't quite line up correctly. what you will have to do when installing the metal pipe is to try to minimize the angle where the j-boot bends as much as possible, this is the key to making it fit right;

[nize]

i was unhappy with the way the lindsey j-boot adapter pipe obstructed airflow through the bend in the j-boot, so after some more tinkering, i cut a section out to improve the fit. i'll let the photos do the talking;



before;


and after;

[951Boost]

Whow! That looks like it was a big obstruction, the fix should be a big help. Thanx for the update.

[JoshB]

Any dyno numbers yet?

[nize]

preliminary dyno shows around 317whp, which is a gain of around 50whp from the previous 270whp, so approximately +18%. i'm still in the tuning process and haven't had much time to spend tinkering with it to fine-tune it yet. it's getting close though.

[nize]

vendor info updated.

[Lawrence Coppari]

Nize,

What octane are you using?

[nize]

92 octane chevron, ordinary pump gas.

i'd like to get hold of some toluene for some 'tests', but it's proving to be difficult to get hold of for a reasonable price (ie; under $3/gallon).

[Lawrence Coppari]

The reason I asked is because when I purchased my upgrades 10 years ago, the kit came with three orifices that can be used in the banjo bolt to make 1.0, 1.1, and 1.2 bars of boost. I have been using the 1.1 boost orifice for a number of years. Attached to the 1.2 bar orifice was a handwritten note indicating I should use 100 octane fuel with a boost level of 1.2. Yet, I hear of many others running higher levels of boost using pump gas. My fuel injectors are stock but have been reconditioned professionally.

I'd like to turn up the wick a little more. The newer cars keep getting more and more powerful forcing me to go up higher on the rpm band when at the track. High rpm is rough on these engines so I'd much rather use higher boost than higher rpm. Car has about 90 track events on it with no problems. What do you think about 1.2 bars?

[nize]

1.2bar = 17.405 PSI at sea level.

my motor is tuned to 22psi on 92 octane chevron pump gas, though i normally keep it at 17psi.

as long as your motor and related items (plugs, injectors, wg, fuel pump, etc.) are okay, and as long as you can monitor your a/f to make sure it's not going too lean, i don't see why you can't just run 1.2bar with 92 octane.

the only potential problem i can see with running 1.2bar by restricting the banjo bolt (essentially the wastegate control line), is what if one day you get a tank of bad gas? the factory stock setup can automatically turn the boost down when it detects knock from bad gas, but a banjo bolt restrictor will prevent that, potentially causing knock damage.

do you have a digital knock counter? it's a very worthwhile mod and relatively easy to make for around $20. it will also allow you to diagnose issues before they become problems.

[Lawrence Coppari]

No, I do not have a digital knock counter. Where can I find plans? Website? Thanks.