Pirate87's Holset HX35 boosted RB25 thread- Diesel Turbo FTW!!

[pirate87]

*All info reflects the best of my knowledge, but please if I do err, correct me!

Ok guys, school has kept me off the forum actively for about a year now, but I've recently started trolling again only to find a lot of questions about the Holset HX35 and its application to the RB series of motors.

The Holset, as has been said many times over, is a great turbo. It flows great, and is nearly bullet proof, plus they can be had for about $250 on ebay. I am going to talk specifically about the HX35, but much of what I say also applies to the HY35 (smaller compressor) and the H1C (slightly older).

Here is a link to the Cummings page about the HX35, for basic info on the turbo:

http://www.holset.co.uk/files/...5.php

So.... It all began when my previous turbo a TO4E just wouldn't spool fast enough. I set to thinking about cheap alternatives and quickly came across the HX35. Days later I purchased one off of ebay for $250 shipped and it arrived soon after. The turbo came internally wastegated, but I run an aftermarket manifold with an external wastegate (the XO2 top mount),so I removed the actuator and welded the flap shut. The specific turbo I purchsed also came with a V-Band adapter for the down pipe which made fabbing things very easy.

Here is my setup installed, which has remained the same (and reliable) for the past 6 months.



As you can see I run a "Greddy" plenum, Q45 throttle body, Z32 maf, all tuned on a Power FC.

The HX35, simply, is a large turbo. The compressor housing is almost 11 inches across at its widest point, so to fit it mounted to the top mount manifold, I had to shave about 2 mm off the compressor housing and the valve cover. Also the compressor had to be clocked pointing straight down, where its thinnest point aligned with the valve cover.

Now that the turbo was fitted to the manifold I had to hook up the oil lines. The oil return is the same as most T3 turbos as well as the stock RB dump tube, which I reused for the return. The oil feed is slightly larger than a standard T3 so I had to get an adapter to get my lines to fit. I cannot remember the exact size, but if anyone else knows, please comment. Also, the turbo is not water cooled so anyone converting from a stocker would have to plug those lines.

The compressor intake is 4 inches in diameter so a 4" to 3" silicone coupler was used to hook everything up. The compressor outlet, being clocked to the ground required me to rig my charge pipes in the crazy snake route shown. Soon I will weld a 90º bend to the outlet to solve that annoyance.

OK, we've come along way and the turbo is finally ready to sp-sp-sp-SPOOOL!

I will soon post video to accompany this section, but for now you'll just have to take my word for it. In second gear from a 2000 rpm roll about 20 mph for me, I mash the gas. Of course there is lag, but at about 2800-3000 rpm boost starts to build until at about 3500-3800 rpm a "spike" is felt when the boost jumps from 5 psi to 10 psi, where I have my gate set, and holds to the redline- 6900 rpm.

On my last tune the car put down 300 hp somewhere near the redline at just under 12 psi.

Off to work for now, but more pics and video will follow. Hope I've helped to answer alot of questions!

[rb25drag]

If you kept it Internaly wastegated couldn't you put a boost controller on it and limit the boost?

[gawdzilla]

you might want to rotate the turbine housing so the oil feed and drain are more vertical.. looks like your oil feed is coming in from about 10 or 11 o clock

[pirate87]

If you kept it Internaly wastegated couldn't you put a boost controller on it and limit the boost?

Its externally wastegated with a boost controller inline. But yes, to your question.

you might want to rotate the turbine housing so the oil feed and drain are more vertical.. looks like your oil feed is coming in from about 10 or 11 o clock

I've heard this before, but exactly why is perfectly vertical better? Does oil pressure build b/c it can't drain as fast?

[kjlindgr]

Turbos drain with gravity so vertical is ideal.

[rb25drag]

[QUOTE=pirate87] The turbo came internally wastegated,

QUOTE]

You said the turbo came internally? Is there anything wrong with keeping it internally and adding a boost controller? Or is there a reason you make it external> reason is for if you wanted to keep the stock manifold.

[pirate87]

The turbo came internally wastegated,

QUOTE]

You said the turbo came internally? Is there anything wrong with keeping it internally and adding a boost controller? Or is there a reason you make it external> reason is for if you wanted to keep the stock manifold.

I already had an external setup...there's no reason the internal setup wouldn't work except I'm nt sure what the stock holset actuator spring is set for. It could be quite high since it is a deisel turbo.

[rb25drag]

That was my question, If I decided to stay with internal wastegate on one of these turbo's and still be able to control the boost with a boost controller? or if the actuator is too high and you have to change it to external to control it?

[BoostFab]

You said the turbo came internally? Is there anything wrong with keeping it internally and adding a boost controller? Or is there a reason you make it external> reason is for if you wanted to keep the stock manifold.

anyways, as for your question; you can keep the wastegate that comes with the turbo, but the problem is you don't know at what boost level it will activate---because diesel trucks boosts these suckers near 30psi. I wouldn't recommend anyone running it unless you know it's actual boost rating. beside, an external wastegate will be more stable and you still can plug in a boost controller at your will.

[rb25drag]

Does anyone have a picture of the stock manifold modified with an external wastegate?

Thanks for the info guys! I wanna learn all the turbo options for this motor! I have alot of experimenting im doing in the near future.

[Cjmartz2k]

Here are my spooling vids:





And some beating on it vids:





All the other vids are with a TO4e, so don't use them as a gauge.

Pirate--not trying to steal you thread or anything, just trying to add to the Holset info.

[pirate87]

That was my question, If I decided to stay with internal wastegate on one of these turbo's and still be able to control the boost with a boost controller? or if the actuator is too high and you have to change it to external to control it?

I guess I misunderstood the first time . I believe I read somewhere that the HX35 actuator is set to open at 21 psi.

[nizmo zilvia]

WOW!!! CRAZY FAST!!!!!!!!

Can't wait to invest in it!!!!

[pirate87]

Here are my spooling vids:





And some beating on it vids:





All the other vids are with a TO4e, so don't use them as a gauge.

Pirate--not trying to steal you thread or anything, just trying to add to the Holset info.

Hey man, the vids are great! Thanks for adding to the thread. Yours seems to spool far faster than mine? Can you provide more details on your setup? It looks like you were boosting to about 15psi?

[Bwana]

Actuators are fairly simple to source and replace. I definitely wouldn't recommend running on the stock Cummins actuator...

[rb 90 240]

so Im curious, 300wheel on the turbo upgrade with tune? I was reading on aem and there was a guy on there making almost 300 on a rb25 with bolt ons and the ems tuned. Is there more room in this turbo upgrade with the upgraded manifold and all to make over 300? I can get a hx35 from a friend who just did twins for a pulling truck and it would be next to free. I just need to reach my goal of around 375 wheel and trying to find a good turbo to go with. Im scared to try my turbo I have now as I think the turbine wheel is going to be too small.

[neonbomb]

Its externally wastegated with a boost controller inline. But yes, to your question.

I've heard this before, but exactly why is perfectly vertical better? Does oil pressure build b/c it can't drain as fast?

Oil does not 'drain' from the turbocharger nor any part of the motor so no, placement of in and outlet feeds will not matter on a pressurized volute shaped object (aka a turbocharger).

Great turbo and try and keep holset a secret

[Cjmartz2k]

Hey man, the vids are great! Thanks for adding to the thread. Yours seems to spool far faster than mine? Can you provide more details on your setup? It looks like you were boosting to about 15psi?

Glad you like them! It's a bone stock RB25, HKS log style manifold and wastegate (38mm with no boost creep ) and it's 1.5 bar which is abotu 22psi. Gears are stock Skyline 4.37's. I'm not sure why it would spool quicker than yours. It's a hybrid, so it's got an even bigger compressor wheel on it.

[Biggamehit]

Looks good CJ... cant wait Untill i get mine... .... i have started to look around on this forum more because im about to break into the RB world after all these years....

im a Holset guy myself.. good stuff man..

Luckly my OLDER H1C lol didn't come with an internal wastegate..... but yea you don't wanna run the stock wastegate that comes with the turbo..they are built to see a much bigger signal... that chances of spikage is high

this site was helpful to me when i really got into holset's some years back

http://dodgeram.org/tech/dsl/FAQ/turbo_faq.htm

quick chart i made so you don't have to link up to the site if you don't want to

Boost levels for respective dodge ram truck years.....

Modified by Biggamehit at 1:35 AM 1/18/2008
Modified by Biggamehit at 7:40 AM 1/18/2008

[Kansei240sx]

That looks good there.

A few questions though. What size exhaust housing is that? 14 cm, 12cm?

I am hoping you are running a conservative tune on that 10 psi. I know those turbos come to life at higher pressures and the flow increases dramatically over another 5 psi, but how are you only making 300 rwhp?

I am making 307~ on a good day with factory everything more or less.

Greddy manifoldSAFCAVCRFMICDivored dp3" exhuast

all the basic bolt ons. running a 11.9-12.1 afr on 20 degree timing.

Im in the process of upgrading injectors, ECU, and turbo, and i have a mind set on that actual manifold, and turbo, although ill probably actually do a smaller exhaust housing, per say the 12 or 14.

And what injectors are you running? If you're on stock, ill hold my comments because 300 to low 300's is a feat on stock injectors for the 25. I say, "cranketh thine boost! and maketh powa!"

[pirate87]

That looks good there.

A few questions though. What size exhaust housing is that? 14 cm, 12cm?

I am hoping you are running a conservative tune on that 10 psi. I know those turbos come to life at higher pressures and the flow increases dramatically over another 5 psi, but how are you only making 300 rwhp?

I am making 307~ on a good day with factory everything more or less.

Greddy manifoldSAFCAVCRFMICDivored dp3" exhuast

all the basic bolt ons. running a 11.9-12.1 afr on 20 degree timing.

Im in the process of upgrading injectors, ECU, and turbo, and i have a mind set on that actual manifold, and turbo, although ill probably actually do a smaller exhaust housing, per say the 12 or 14.

And what injectors are you running? If you're on stock, ill hold my comments because 300 to low 300's is a feat on stock injectors for the 25. I say, "cranketh thine boost! and maketh powa!"

I am not positive but based on bigmehit's chart the turbine housing is 12cm, and your suspicions were correct I am still running stock injectors, so I am am boost limited as of now! Soon to be changed.

The only thing about my manifold and turbo combo that wasn't ideal was the grinding I had to do to shave off a few mm from the compressor and valve cover. This has lasted me, but I'm sure it isn't the best option. Ideally, I probably should have rewelded the flange on the manifold, but oh well.

[Shocker]

you bastard, those videos make me want my car to be running so damn bad!! ahh I miss that noise.

this seems like very good cheap turbo that provides excellent results.

[Biggamehit]

yea the turbos are cheap because they are for a truck application.... but they can get pricey..

but these turbos are bad *** awesome quality... one night while going home after welding up my exhaust..... i noticed my oil pressure was acting up.... so i pull over and wow ..... big hole in my oil pan from a puncture. i was driving a very high rate of speed... lets just say my turbo spooled for little over a mile with no oil at all... I took it apart and everything was fine.

hope im not thread jacking. here is a little more info on the great holset.

zer...83671

few pics of where i got mine from... much much more bro's he also has brand spanking new ones for about 300-500 bucks

Modified by Biggamehit at 7:30 AM 1/18/2008

Modified by Biggamehit at 7:33 AM 1/18/2008
Modified by Biggamehit at 7:50 AM 1/18/2008

[Shocker]

lol thats what I meant cheap to buy, not in quality.

[Biggamehit]

Oh no doubt bro. i understood you.. i was just piggy backing on it lol

[Shocker]

Pirate, or Cj how long till you guys get on the dyno or get a trap speed with this turbo?

[grenade180sx]

so wait.. i have a 20. and i cant find a 9cm housing.

spool is kinda laggy for drifting and a 20 is gonna be another 300-500rpms

any advice on which one to rock?

and please link the shop where you took that pic!

[BoostFab]

so wait.. i have a 20. and i cant find a 9cm housing.

spool is kinda laggy for drifting and a 20 is gonna be another 300-500rpms

any advice on which one to rock?

and please link the shop where you took that pic!

you can step down to the HX25 or HX30

[Biggamehit]

good answer bro... the hx30 goes unnoticed and the hx25 is another good one...

here is a pic of the hx25... will bolt right up.... T2 flanged

[Cameron]

HEY YOU GUUUUYYSSSSSS!

CHECK OUT WHAT I BEEN DOING WHILE I WAS AWAY!

!!!!!!!!!!!!!!



Brand NEW H1E!!!

Mock up of the exhaust manifold on there.



oh and granade. ditch the stock housing bro. get a Hx35 and get the bullseye housing, .58ar or something, which is like 7cm..

they are only like 250..

dont drop down from the 35...

Oh and guys i realize it is a T4 lol. Im getting the Bullseye Housing for the Hx40(H1E) and changing it to T3.

its like a .79AR