Hey Guys,

I have been searching every post/website/ every turbo book. Still need an idea of which Holset turbine housing would be best. Here is what it's going on...

5.2L magnum
stock long block
mild ported EQ heads
arp stud-MLS gaskets
93' magnum exh. manifolds (large collector)
208 Hyd roller cam 114LSA >.500" lift, 1.6rr
rpm air gap intake EFI, 53mm TB
MPP CPU with BTM, 24inj/FMU or with standalone.
auto
street/bracket racer, 5800rpm shift, 6000rpm redline

Want to run 8/10psi street on 93oct. air/air inter-cooler and (later) 14psi on occasion running race/mix gas or meth injection at the track.
If I go twins I'll use either HY or HX 35, My question is...
1. How much of difference in spool time/boost threshold between 2-HYs or 2-HXs? Is it like 300rpm sooner spool? I'm looking for a boost threshold in low/mid 2000rpms and full boost by 2800/3000rpms(street 8/10psi) and by 3200/3400 for 14psi trim, which turbo would be best?

2. If I go single, I'm going to run a 2 1/8"-2 1/4" crossover to a Holset. I was looking at using a HX55. I know there are atlest 19cm,22, 25 housings avail. Which would be the one I need? I know their housings are heavy, can a "T" housing fit/be modded to fit?

 

I dont know for the twins, but single an hx55 should be good and if you want a fast spooling turbo go with a small turbine housing 19cm, or 22cm

 

Is there a reason you are set on Holsets?

If you don't own either of the two options in your post, I feel there is turbos better suited to your low boost application.
Remember Holsets are from diesels and perform best at much higher pressure ratios than you are talking of running.

 

1. I can get rebuildable holsets cheap, I can build 2 (complete)holset kits for the price of 1 setup using a (GT series, s476 or Precision turbo). I would use a T-72 if need be,but still $800, but the holset seem to have steeper surge lines(less surge prone), allowing a wider powerband(which is one of my requirements). Im looking for a wide 3000+rpms 2800/3000-6000rpm, not a 2000rpm powerband, this isn't a "drag only" car, I am only running to a 6000rpm redline.
2. AS for the better turbo's for low boost/ holsets are for high boost, that really isn't the case. The holset just stay eff. /have wider maps at high P/Rs. The HX35 has an as wide a map at low boost as the t04e50(it is comparable to), and the hx55 has a wider map than the S362 turbo (it is comparable to). They have a more vertical surge line allowing more low end flow/ boost at low rpm/less surge.
HX55 (map flow capacity)
at 1.5p/r hx55 12-48lbs. vs. s362 14-51
2.0P/R hx55 19-62lbs. vs. s362 26-64
A HX35 is basicly a T04e50 with more high boost potential,I attached a pic. #ad


The only problem with the holsets are their turbine housing sizes/weight, # of options.

#ad

 

Here is a comparisons of a hx55-b98 compressor map to T-66I made. #ad


#ad

 

Is anybody running twin Holset 35s or a HX 52/55/60 on a v8( any make) in the 5.0-5.7L range????

Just need any idea on the turbine sizing to spool rpm. Tried the borg warner matchbot, I think it is very optimistic or their turboes spool 500+rpms faster than anything else of the same size. It said a 1.25 a/r 83mm turbine on their 100s71 (s400sx 71mm) would be capable of getting 14psi by 2500rpms, 8psi by 2200??? From using their calculations on GT42 turbine map it looks like a 1.15 A/R would be ideal, all points fall on it's curve?

I see most guys with single 100-102mm turbos running .84-.96 a/r's(don't know how well they spool). If your one of them... what type of boost threshold and full boost rpms are you seeing???
Getting full boost (2800-3200rpm) is more important than max HP for what I want. Emailed every turbo manufacturer, few dealers with no response Hate to end up having to buy multiple housings to test them all.

 

I guess no has any experience to offer, with a small block setup with these holsets, FWIW... I finally got a response from a turbo dealer and they recommended, "From PTE and Turbonetics I would run the 7675 CEA PTE and 7675F1 from turbonetics, Both with the .96ar T4
Using a Garrett turbo, I would run our GT45 80mm billet 1.15T4i with the 77mm turbine wheel."

For anyone that needs some clear/easy to read, HOLSET HX35, HX40, HX55, HX60, HX82 compressor maps and some from a few other brands here is a website:

http://www.musclecardiy.com/performance/choosing-turbo-system-manufacturer-right/

 

Just Got a response from a Precision Turbo dealer and they recommended CEA 7685 with a 1.28 A/R

 

ATP just got back to me and said the GTX4294R would work for my street/strip setup with the 1.01A/R, If I was race only, more HP vs. response oriented, then they would have gone with the GTX4594r.

 

The member Tbirds has a twin H1E set up on his SBC, not quite what you're requesting but he might be worth talking to.

Site vendor VS Racing has a few turbos similar in size to the ones that have been recommended to you. They are from China but seem to perform very well for a more budget oriented option.

 

I haven't gotten any mopar response, of anyone running them. LS guys are not applicable as most are looking for the # only a "high boost Supra dyno curve", AKA all top end/no mid let alone bottom end response. Like running twin T-70s on a 4.8L. I am looking for a torque curve looking more like that of a 540ci big block. My problem is am looking for more street friendly fun with a short off/on boost lag time with power in the 3000-6000rpm range. I am also not looking to kill any possible power by running a single hx-35/H1E/hx-40 in <60%eff. on a V8. Twin H1e would be good if I was a stroker or a higher revving 5.9.
I got the twin 35s idea from 2.2/2.5L mopar guys(basicly half my motor) running them and getting the response Im looking for and still making 350-400+hp on a single. 1 guy is running 10s on a HY-35 ( small turbine housing)2.2L. I thought I would be cheaper easier running a single. Plus I have plenty of room, I can can fit on the P/S of my engine. Maybe I'll look for a 551vgt and make a actuator for the turbine, since hx52/55 housings are few in options??? I just wish it wasn't so F'n heavy.

 

I forgot, VS RACING, recommended the 7675 CEA PTE, or their GT4580 1.15a/r.

 

Seems like the stock HX55 is only a 67mm, while a HX60/HT3B is a 76mm and the 52PRO is a 71mm? I think the PRO52 is best for a mild smallblock. From the 67mm HX55 I would be at the limit compressor Eff. wise @ 1.5 p/r and 2.0 p/r my P/R ranges,NFG

I have no idea what flow holset uses on the graphs on their website???? but it does match up with any normal flow rating (lbs/min, m3/s, M3/min, kg/sec, kg/min KG per hr... per lunar cycle, LOL. From comparing what is on their site to other charts for the same wheel(HX40) It looks like there is a .805 conversion to lbs/min. An example HX40 vs. pro/super 40 map the standard 40 flow'd 82/83..what ever. On normal lbs/min charts it, a HX40 B85 flow'd 66 lbs/min. So converting the Holset fantasy flow chart to standard LBS/MIN a PRO52 with a mystery 118 flow rating would convert to 95 LBS/MIN max flow @ 3 p/r. It's map would max @ 84 lbs/min @ 2.0 P/R and 64 lbs/min @ 1.5P/R... perfect for a slightly modded S/S smallblock 320's-360's. So... A Pro52 is slightly bigger than a T76!!! Comparing the 2:

T76- 62lbs/min @ 1.5 P/R, 79 lbs/min @ 2 P/R, 93 lbs/min MAX@ 2.4?P/R
(((VERSUS))))
PRO52- 64 lbs/min @ 1.5 P/R, 84 lbs/min @ 2 P/R, 95 lbs/min MAX@ 3 P/R

FYI, a Hx60 iws comperable to a GT4708 garrett 114 lbs/min @ 3.1p/r

 

ON3 recommended a T76 .96a/r
Tialsports recommended a gt4294 or 4202 with the 1.01 a/r
Exile said the GT4294r would reach full boost 3500<3800rpms and would be good for 650-700hp at 14psi also recommended 3.73 and a TQ
Could not get Garrett to answer any email, had to emailed their parent company HONEYWELL. They said a GT4088R would be best for a quick spooling street setup with a 1.06 a/r. I think that turbo is too small as it would put me in the 68% range at 8psi and I would be on the choke line at 14psi. The guy at Honeywell just kept saying the gtx4294r was too big and is rated for 1000hp and at 600hp it wouldn't be used to it's potential?? It is sad that even the guy at honeywell couldn't understand that, "1000hp turbo" choked at 60lbs/min at 1.5p/r and was only good for 80lbs/min at 2 p/r.

I've heard that the new gt4094r didn't perform well compared to the gt4294r, guess it is too much of a mismatch with wheel sizes. Has anybody seen any result/comparisons/used the gt4594R. I think the large turbine would allow less Backpressure for larger cubic inch engines running low boost vs. the gt4294's?

 

*****UPDATE response from dealers*****

honeywell- GTX4294r is too big,recommends - gtx4088r with 1.06 a/r

himni-racing- Great Customer Service, (BIG THANKS ETHAN) said the 100s74 would perfect for full drag, but laggy on the street, recommended S400sx3-67.6mm for early spool full boost 3000<3500 rpms. They also said a 1 step change in A/r housing equals a spools change of +/-200-300rpms.

turbokits- gtx3582r 1.06 a/r or a s373 bullseye power w/ .91 a/r , I think that is too small for anything other than stock.

atpturbo- GTX4294R w/ 1.01 a/r (good choice) but would reach full boost 3500<3800, for earlier boost they recommend the gt4088R

The NO RESPONSE, SH*T customer service group...
Garrett
turbonetics
hellion
cxracing
agpturbo
moranmotorsports
forcedinductions
dpraceparts
full-race
nolimitsmotorsports
buschur racing
Swapped and boosted.com

 

you could run a gt45 with the 69mm comp they cost about 300.00

something with about a 75mm compressor would be better though

 

Thanks, I've seen the GTX4594, but I think it would be laggier than the GT42 version, over kit for a setup <650hp. I just can't find a Garrett distributor OR "Garrett themselves" that has any idea about when it might reach full boost or how it spools vs. say a GTX4294. No one can give me an answer as to when would I want to get a gt45 with the 94mm wheel over a gt42 or gt40 with the same wheel.

I am going to start a new post to take a poll/find out what spool time change people seen with different turbine wheel size/ a/r size changes. I also haven't found anyone that has dyno run comparisons that show, how much an A/R size change affects HP curve/spool time. For example, from a 1.28 a/r to a 1.01 a/r on a single turbo v8 5.x Liter. I just get that saying, " larger a/r for topend, smaller for response", it just makes them look like they don't know what their doing, if you don't have an actual RPM# of what they've actually seen on a engine. 95% of all speed parts sellers don't have any first hand experience with the parts they are selling, they just read out of the manufacturer's sales brochure. I've had the same problems with a " Mopar cam supplier" stating powerbands,etc. and when I asked him what they've seen it make on a 5.2 magnum they said, " We have never dyno'd that camshaft".

 

on our shop truck we run a stock 350 with a 1103 summit cam 2 inch crossover 3.07gears and a 69mm compressor 77/88mm turb. gt45 and it spools at about 25-3000 rpm

 

Thanks for the response, Is that "starts to spool" rpm, or is that "full boost"? What boost set at on the that engine?

UPDATE:
FINALLY got some "late" EMAIL responses,
TURBONETICS- recommended a Hp7075 1.15 a/r T4
Full-race - S400sx 67mm 1.00/1.1 a/r T4

 

at 2500 opening the throttle we hit about 9psi really quick,, maybe a second,, gated for 8-10psi