Swapping an HY for an HX. Good or Bad?

[K_Arts]

Ok guys... . I'm getting ready to drive from Colorado to LA, but here's my question. On this drive the Wife and I will be taking her 2k1. 5 auto that has an HY-35.



Now I just took out my HX-35 and installed one of Piers new tricked out HX-35's. I have been thinking seriously about putting my stock HX-35 into the wifes truck, but I am worred about performance in the mountains. Being that the HY-35 only has a 9cm2 housing, it will spool up quicker then the HX-35 with a 12cm2 housing. But while we are in the mountains, which is the best turbo to have?



Also, after putting gauges in the wifes truck, I have noticed that her wastgate opens about 20lbs of boost. Now if I put in my stock HX-35 and the stock boost elbow, will it produce too much boost to set an overboost code in the ECM? Which turbo do you guys will be the best option? Also take in affect that we will be driving though the extreme heat of Las Vegas. Hmm... I don't know what to do. Will the HX-35 keep EGT's lower?



As you can see... . turbo's are not my specialty.



Thanks guys



Kev

 

[Dave Fritz]

K_Arts,



The HY-35 and HX-35 are functionally equivalent under most engine loads, and the wastegates on both turbos are set for the same boost level.



A truck with an automatic transmission has to meet soot emissions standards when torque converter slip allows the engine accelerate quickly. This does not usually happen with a manual transmission because for the engine speed to increase, the truck must accelerate - and that takes time. The HY-35 builds boost a little more quickly than the HX-35 does when the engine load is light, so the HY-35 is better suited to stop-and-go driving with an automatic transmission.



While the HY-35 spools up a little more quickly at light loads and low engine speeds, it does not breath as well at higher speeds under a heavy load. Compared to the HY-35, the HX-35 should slightly reduce EGT when climbing long grades with an unmodified engine. The addition of a fueling box or larger injectors would definitely tip the scales toward the HX-35, which has a higher choke point than the HY-35 does.



Personally, I would install the HX35 on the truck because (IMO) it is better suited to mountain driving. As always - YMMV!





Dave

 

[K_Arts]

Thanks Dave. Something I did leave out though is that on the trip to LA, the truck will be empty..... well except for luggage... LOL



Kev