turbo advice

[matches]

I will be installing new 40hp injectors, three piece pulse exhaust manifold and new 16cm housing, Ill also be turning up the pump. My question is should I replace my turbo with the hx35 while I have everything apart. I'll do it if I'm going to benefit from more power or faster boost and lower temps, any input will help. I'm looking at the stuff from piers, and will have a shop install it and dyno tune also.

 

[dpuckett]

Your H1C should be able to handle it, if the pump isnt tweaked too much. If you have the cash, I'd say get the PDR35. It has a higher efficiency range than the H1C. WIth stock injectors in a 92, I could hit 30psi, out of the 25 or so psi efficiency range of the H1C. I think the PDR35 is good to about 38psi. Doesnt mean you cant go above that mark, but you get into drive pressure vs boost obtained, and it gets less and less favorable as you go up.



I had a worn H1C on my pickup, and I upgraded when I had the chance. Good difference in spoolup, dropped EGT by about 100 (and I lack an intercooler); cruise down 50 or so. Bad part was plumbing the wolf in there... ...



Have fun, and hapy BOMBing.



Daniel

 

[matches]

Thanks for the input. Is the pdr35 a direct bolt in or will I have to modify anything?

 

[dpuckett]

If you are intercooled, it is a direct bolt on. I am lacking an intercooler, hence the difficulty installing it. Or, better put, it took some imagination to get it to work. It hold 40+psi, though.



DP

 

[matches]

Yeah I got lucky and bought the one with the intercooler. When I bought it I didn't know about the 91. 5s being intercooled. I also have the cross flow radiator and bigger fan assembly, so I lucked out.

 

[BushWakr - RIP]

JMO, but ya,... . HX35/16 is a great combo with room to grow into if you want to tweak and maybe tow as well... . fun combo for me. .



pastor bob... .

 

[bgilbert]

DP, PB, how bout a PDR Hx-40 on a 89 non-IC truck?

 

[dpuckett]

Bill, you and I covered this topic already... ... . INTERCOOLER first, rememeber? Maybe you been drinkin too many of them wobbly colas Pastor Bob mentioned. :-laf



-DP

 

[bgilbert]

ARgggg yeah I know, but I don't want to spend the money twice ya know like hx35 then down the road up to a hx40, why not just bite the big one first and go to the 40. . ?? Then find that 91. 5-93 parts truck and use the intercooled parts off it... Basically trying to find out how it would run with few ponies and a hx40... real doggy never spool up, take forever, huge smoke through the rpm range til the 40 spools like 3grand? I've seen a hx55 on a 2nd gen 12v that didnt have the power/fuel to spool it and it smoked like hell til like 4grand... ???

 

[matches]

should I go for the PODs if I'm going to get the pdr35 turbo or will they over fuel, and what boost pressures should I expect from that set-up?

 

[dpuckett]

Bill-

You could go for a HX35, then if you need it, get a 40 compressor wheel and compressor housing.



matches-

the PDR HX35 shoudl handle that set up. I think the Pastor has topped 40psi with his.



-DP

 

[matches]

will 40psi be pushing the limits on my head gasket?

 

[dpuckett]

40psi shouldnt, empahsis on the SHOULD part. I have seen 40+, probably closing in on 45-48, (gauge only goes to 40) judging by throttle position & RPM when I hit the 40. I think 50psi is the assumed safe pressure for the stock head gasket over the long term. Then, after that, I'm not sure where you go. Takes a LOT of fuel to get 50spi. That, or a 10-12cm housing on a hx50.



-DP

 

[cerberusiam]

Daniels ramblings aside, 40 psi is pushing the limit of a stock head gasket. It would be best to keep it in the 35 to 38 psi range for a buffer and the midified HX35 is starting to get out of its map above 38 psi. Doesn't mean it won't go higher or work well but it is starting to push its limits. Daniel can consistently hit 45 psi or higher and the first time I would do it the head gasket would let go. I suspect a lot will have to do with miles, how many times it has gotten really warm, the quality of machining at build, etc.



But then playing it safe is no fun so if your not worried about replacing the gasket go for it.

 

[Greenleaf]

Guys,

The HX35 is very versatile. For instance; You could install the '35 in stock form, then upgrade it to the SMALLER HX40 compressor, then again upgrade it to the LARGER HX40 compressor. This is my plan and if the smaller '40 compressor wheel don't work out for me, ie too much temps, I'll have it machined again and a bit larger wheel installed. This is very much a "Progressively Economical" plan.



In short; you don't have to go out and spend BIG $$ on the '40 right off, ie bite the bullet. When you can adjust(taylor) the '35 to fit your individual needs. Heck. it's like eating cake WITH ice cream!! Oo.



Hope I could be of help.



-S

 

[BushWakr - RIP]

I really like the '35... . it is a very reliable unit, it has the extended map range as mentioned, it spools quicker, has cooler boost over all and is pretty tough to hurt.

In my case I have really "tested" the durability of mine.....

I have had runs of 48+psi and it just howled under there... . yes, it was beyond the map at that point, no question, but it hung in and kept on spinnin.

We do not recommend those kinds of boost levels for that turbo for obvious reasons, but it still hung in there.

You can alter the hybrid 35 and put in the larger '40 pinwheel and you end up with what I think is called the "jammer" ( I may have the name wrong here so don't hold me to it. )

It will spool slower, and it will be more prone shaft stressing due to higher rotational mass of the pinwheel. They are, I believe, more prone to problems with compressor stall related failures due to the larger pinwheel, as well as what I describe as "cavitation" at the blade/intake air interface. (often called flutter).

Again, I stand to be corrected on the "label" but the turbo will move more air if you do that upgrade.





pastor bob... .

 

[Greenleaf]

Yeah! .....................

... ... ... ... What I said



-S