Is the HX35 overkill for 400hp? What about street-ability?

[smills1840]

Like the title says, is the HX35 going to be overkill for 400whp on a GSX?

I'm really liking the holset turbos, specifically the hx35 for a little quicker spool (from what I read) compared to the hx40.

My build is planned out like this:

This build list is in no way set in stone, so PLEASE feel free to replace any parts listed below with other parts!

HX35
BEP .55 housing
PR ex mani
Recirc O2 housing with Tial WG
3" turbo back
FMIC
Walbro 255 rewire
1000cc + injectors (still reading up on which ones to go with)
DSMlink V3

My main engine question is: Will I need cams? I am not completely opposed, but unlike many others, I don't like a lopey idle. But I'll probably sacrifice the sound if it means big gains.

And of course all other supporting mods:
Bolts/hardware
gaskets
head studs
etc.

Suspension:
Koni Yellows
Ground Control Coilover kit
Prothane Total Kit bushings
Sway/strut bars

Timing belt and full engine gasket rebuild was done ~2,000 miles ago

No balance shaft delete, haven't decided if I'm doing that yet.

So my questions are:

Will this setup be overkill for 400whp? If this will do more, that's awesome! But my goal right now is 400whp.

This setup will maybe be tracked once a month, if that. It will be purely a street car. It's also my DD. Will this setup be streetable? I know there are a lot of factors that play into this, but is this a pretty reliable looking setup if done right?

Thanks guys, and I am 110% open to criticism!

 

[smills1840]

I appreciate all the responses guys!

I'm definitely interested in building a 9:1 engine, but I just don't think I'll have the funds to do so.

My1gLaser, when you had the FP mani and the BEP .55, did you also have a 9:1 CR?

 

[Seamus]

I'm 20 over with wiseco 8.5

untouchable, what cams do you have?

i kow there are more powerful cams available, but I like the BC 272's because they don't hurt spool much but still give you that little bit more Ve needed to see over 40lbs/min on a 20g.

I did gain 8lbs/min with the hx, so it definatly makes more power up top. But to me it feels like truely going from a small turbo to a large turbo. Thats what i love about the 20g. It will make an honest 400whp, that is attainable by your average joe. but it feels like a small turbo.

 

[My1GLaser]

My1gLaser, when you had the FP mani and the BEP .55, did you also have a 9:1 CR?

Yes.

 

[smills1840]

I'm 20 over with wiseco 8.5

untouchable, what cams do you have?

i kow there are more powerful cams available, but I like the BC 272's because they don't hurt spool much but still give you that little bit more Ve needed to see over 40lbs/min on a 20g.

I did gain 8lbs/min with the hx, so it definatly makes more power up top. But to me it feels like truely going from a small turbo to a large turbo. Thats what i love about the 20g. It will make an honest 400whp, that is attainable by your average joe. but it feels like a small turbo.

These kinds of posts are making me lean more towards the 20g. I'll have to look into it some more.

Yes.

Well that's kind of a bummer. It seems like the HX35 might not spool fast enough for my liking on a stock engine.

 

[9D9X]

I still think that an fp green would be the best....spool and power...and the easy install.. No different manifolds or turbine housings to look for and hope to work.

 

[Seamus]

These kinds of posts are making me lean more towards the 20g. I'll have to look into it some more.



Well that's kind of a bummer. It seems like the HX35 might not spool fast enough for my liking on a stock engine.

If you want more top end with the 20g down the road you can always install a td06h turbine or similar. A brand new td06h tuirbine and shaft is only about $160. i have been using the 20g for a long time and i have used it with 05 and 06 turbines both in 6cm and 7cm housings. The td06h turbine in a heavily ported 6cm housing is a pretty fun little combo too.

I still think that an fp green would be the best....spool and power...and the easy install.. No different manifolds or turbine housings to look for and hope to work.

if your talking pump gas, i think the hx35 and the green are very comparable. The hx35 is a lot cheaper and probably more durable. I wanted a green my entire life and it was always going to be my next turbo. But in recent years, it has become much less attractive in my opinion.

 

[smills1840]

Ya I'm not so sure about the FP green. It seems much more fragile from what I've read.

I think really my only options are the HX35 and the 20g. I don't know anything about 20g's, so I'll have to do some reading.

Thanks again guys, keep the responses coming!

 

[My1GLaser]

I would definitely look into people running the HX-35 on stock CR and pump gas to see what their spool is like. You can also do a similar comparison to people running stock CR vs 9:1 on a 20g and compare the spool times.

I am biased toward the Holset, but I did just hit 60 lb/min on the HX-35 today! 35 psi by 4500 and I hit 60 lb/min peak airflow! Its been about 57 lb/min lately, then I ran a pressure line to the top port on my WG and it holds better up top...finally!!!

 

[smills1840]

But is the lag too bad to have fun with on the street?

 

[My1GLaser]

Pretty much all I do is street driving and I have a blast! If only you lived closer I would take you for a ride. I run a pretty aggressive timing map to help off-boost performance. I never dip below 16* during spoolup, and I am up to 23* by 5500 rpms. (but I just started pushing coolant again, so I may have effed up my HG having all this fun )

It spools so quick that I can still catch my GF off-guard after a year of her riding in it. I can throw her back in the seat before she has a chance to hold on, which I do as often as possible It spools nearly as fast as the 18g I ran. Its torquier before full boost because it moves more volume at a lower pressure than the 18g did.

I hope my experience is closer to the norm for this turbo so as not to be misleading. I assume it is normal performance due to all the pandemonium about the Holset turbos!

 

[Seamus]

Pretty much all I do is street driving and I have a blast! If only you lived closer I would take you for a ride. I run a pretty aggressive timing map to help off-boost performance. I never dip below 16* during spoolup, and I am up to 23* by 5500 rpms. (but I just started pushing coolant again, so I may have effed up my HG having all this fun )

It spools so quick that I can still catch my GF off-guard after a year of her riding in it. I can throw her back in the seat before she has a chance to hold on, which I do as often as possible It spools nearly as fast as the 18g I ran. Its torquier before full boost because it moves more volume at a lower pressure than the 18g did.

I hope my experience is closer to the norm for this turbo so as not to be misleading. I assume it is normal performance due to all the pandemonium about the Holset turbos!

your 18g was an 06sl2 in a 8cm housing though. And it still outspooled the hx35. That is not a very good combo in my opinion. Its basically as big as a 20g wheel, but not near as tall. So it has the same spool as a 20g but more like evo16g performance.

Im not shooting down the hx35, i have one on my car moving 49lbs, and its a blast. But it definatly feels like a laggy big turbo, where a 20g feels like a small quick spooling turbo. the hx is pretty slow going from vacuum to building a few lbs of boost, then it hits hard. A 20g hits 25+ psi as fast as your foot can hit the floorboard.

 

[95gsttsi]

Honestly with the setup your running and a set of 272's. You should have no issues spooling but you will have lag. But as far as just a street car a lil lag never hurts. But here's tye thing with the hx35 its a diesel turbo it doesn't produce fast spool until you reach about 28-35psi. That's why trucks sit at the line forever to spool their turbos they are ment for slower spools. Yes its a great upgrade but honestly its not overkill for a 400whp setup due to most cummins are 300-400whp with the hx35. If you checkout sim's tt talon they ran a hx35 off the manifold to help spool a much larger holsett. Although the build is slighty different. It just comes down to comfortably.

 

[9D9X]

Never heard of problems with the fp green...Ask anyone who has had one and I bet you most of them would love to still have that turbo or still do. I have had my old fp green for years and never had a problem. Pump gas King I tell you...But that choose is up to you. Anything else I can say to change your mind..haha

 

[AshyBone]

wouldn't smaller cams help the spool. Instead of going 272's why not 264's?

 

[ctsellersjr]

i'm running the holset hx35 and i'm changing my turbo next week. It was fun for a while but the lag is just to much for me. even though it got me to 400AWHP the lag is something i can't live with

 

[smills1840]

i'm running the holset hx35 and i'm changing my turbo next week. It was fun for a while but the lag is just to much for me. even though it got me to 400AWHP the lag is something i can't live with

What turbo are you going to?



Also, why does it seem like there is a lot less info on 20g's? If I search for holset info or fp green info, I get a lot more results than when searching for 20g info.

 

[spadepro22]

I have a 20g with a 16g turbine wheel in a downfiring compressor cover and it spools just as fast as the small 16g that I switched from. I only ran it at 17 psi and it was a blast. Can't wait to run it at 25psi. This was a stock 1g 7 bolt bottom and head. From the research I've done the 20g might get you to 400whp on 93 pump and you will have room to grow with better fuel and the hx35 will definitely get you past 400whp with the cost of some lag.

 

[smills1840]

Sort of an "update". I decided to go with a simple 16g build first, and then once I want more I'll either go 20g or HX35. I really appreciate all the help guys!

 

[talon314]

I have about the same setup and am gettin around 400 ecept I have the wh1c. so besides adding cams to your list it seems about right. Go with a steel Braided fuel line and run e85 and it wont be a problem hitting that mark

 

[smills1840]

I have about the same setup and am gettin around 400 ecept I have the wh1c. so besides adding cams to your list it seems about right. Go with a steel Braided fuel line and run e85 and it wont be a problem hitting that mark

I'm not so much worried about big HP numbers now as I am the lag of the bigger turbo. Is your car still streetable with your setup?

 

[dfootedsm]

I seen some posts hear about the difference in fuel causing a difference in spool times? what difference does e-85 and 93 or 100 or 110 play into this

 

[Albert dôyle-]

I love reading these post and comparing turbos. Just from talking to many dsm guys I think turbo depends on more than turbo size. I chose 2.3 stroker and hx35 turbo with 2g head, kelford 272 cams,and bfab twin scroll 12cm. All built for torque and quick spool. Also doing auto swap so hp number will be at least 20% less than manual. 1120 fic injectors. Hopefully installed and dyno number in 3-4 weeks. 20 g is more for 2.0 higher rev. Hx for stroker