Piers' Modified HX35 - Report

[Fred Swanson]

I've posted in other threads about installing and testing Piers' modified HX35 turbo, and decided to open up another thread for posting feedback and questions, and give more details of its performance.



Summary: Intial tests were done with the EZ and DD2's and judicious use of the Hot PE. (Yeah right, like you going to believe this)

Most of this time was spent running around town, and highway and back road driving. I live 30 miles from work in a rural area, and drive into Phoenix everyday, so I get a good mix of highway, 2 lane and city driving each day.

Most noticeable impression is the much quicker spoolup with the new turbo. Lag is almost non existent, and when I drive another truck, it immediately feels like a dog off the line. This is with soft and hard launches.

Plus some hard runs against a fellow TDR member with a modified 12V proved to be interesting. The difference is lag really shows off the line. The new turbo really reacts quick.

This is with normal launches, not power braking.



Next I removed all of the boxes, and kept the DD2's and did some more everyday driving. I was really impressed with the quick spoolup, and driving characteristics. I've tested just the DD2's before, and the lag was very evident. Not so with the new turbo.



EGT's are reduced by 100, and boost is up about 3-4 psi.



I'm getting ready to head up to Canada, and hope to get more results driving in different altitudes and such. But my opinion right now is this is a great turbo. It helps where you need it, and drivability is much improved. It really compliments the other modifications made to the truck.

 

[Sky]

Fred,



What is does your egt's run at on the hwy?

 

[Fred Swanson]

Sky, right now since it is in the 100's I see anywhere from 6-1000 F. We've had some unusually cool days lately and the EGT's are lower. I can say that cool down appears quicker, too.



Are you going to be at the event in Portland on Saturday? If so, you can see for yourself what the EGT's do in your area.

 

[azgearpro]

payback

I am the modified 12v that pusher boy is talking about, and I was very impressed, impressed enough I am going to purchase one to keep up.







P. s.

pusher I have 4 tubes done

 

[Sky]

Fred I will be at Portland, I do want to see that turbo

Thanks!



PS. Did the radio work out ok?

 

[DAWG-1]

What size housing are you running is it a 12,14 or 16?

 

[CumminsPower98]

cscpusher, can you tell us what all was done to this turbo to lower EGT's and get quicker spool up? I just want to know mechanically what makes this turbo so desirable. Thanks

 

[Bob Wagner]

CP98

I would go direct to Piers&copy for all of the details because its a very precise science



check it out and give Piers&copy a call www.piersdiesel.com



That turbo&reg is sweet!

 

[JR2]

I installed Piers new turbo today along with DD3's. Initial testing show that with the EZ and DD's I can not get the EGT over 1100 deg. I have not pushed it real hard yet as I am letting the turbo break in a bit.



Right now all I can say is

 

[24V-DSL]

JR2



Did this replace your HY35, or had you already gone to an HX35 before Piers?



If you did take off an HY did Piers take this as a core?



Piers' is a 12cm housing, right?



Thanks.

 

[Fred Swanson]

Sky, the radio works great. The standard Piers HX35 comes with the 12cm housing, just like a stock HX35. I do not believe the HY35 is usable as a core, but Piers can also answer that, too.

I am going to test the 14cm housing, also. So look for feedback on it, too.

Here is a quote on what is modified on the HX35, from Piers' website.

"The PDR custom turbo is a modified HX35. We take the stock turbo and install a bigger pinwheel on the compressor side, then machine each housing to very close tolerances, that match each individual pinwheel. The result is a turbo that spools up faster than the stock unit & stays within its efficiency range much further. The PDR turbo was designed for you fellows who are towing and/or for those fellows running up to 350hp".



The new pinwheel allows for quicker spoolup which has these benefits:

100 CFM more than the stock turbo, about 4 lb of boost more, and around 150 degrees cooler on EGT's.



I can tell you that the EGT's and the boost are right on.

 

[Vaughn MacKenzie]

Drive pressure?

What I'd be curious to know is how much Piers' turbo might reduce drive pressure in the exhaust manifold. With the ETH and higher compression ratio I was considering an HX40 if I BOMBed heavily so the exhaust manifold pressure wouldn't be sky-high and reduce the likelihood of head gasket failure. As I recall a standard HX35 required about 60-70psi to generate 35-40lbs of boost whereas the HX40 required only about 1/3 to 1/2 that high of exhaust pressure. Piers' turbo would probably help cut drive pressure somewhat but probably not near as much as an HX40 since you still have an outlet less than 3" in diameter compared to the 4" on the HX40.



Just thought this would be an interesting question to ask.



Vaughn

 

[dezrat]

My experiences are as follows,more boost[4lb] and a lower egt of 100. At 5000 ft where i live there is a very slight lag but when she spools up you are gone. Of course alot of it is Bill K's 91 TC which will transfer the power.

I am very impressed.

As usual Piers has produced another fine product.





94 3500 3:54 TST 230/605,215 injectors,Piers turbo[12cm] spring kit , DTT 91TC and vb

 

[JR2]

I replaced the HY with the Piers turbo. Piers will take your HY for a core or you can keep it and pay the core charge. I am going to keep mine in case I ever have a problem and need a turbo right now.



Does anyone have the web address for Piers website?

 

[KatDiesel]

Originally posted by JR2

Does anyone have the web address for Piers website?

Piers Diesel Research



Ask and you shall recieve... .....