best holset for autocross

[ed1380]

Pretty much I'm just looking for the fastest spooling holset that still has a good top end (~50lb of airflow)

Due to cost I can't go with a twin scroll hx-35 (but one day I'll own one)

So I've narrowed it down to a hy35

BUT THEN I saw this post by justin and I'm back to researching < me

The HY in the factory 9cm T3 housing will spool later than the HX in a BEP DSM bolt-on housing.

The turbine wheel itself is indeed smaller on the HY, but the housing a/r and flange is still larger than the BEP DSM housing and the design of the HX wheel is a little more efficient at building boost (taller inducer).

For an auto, I think you'd see the quickest spool out of a HX35 in a bolt-on housing, although you may see a little more peak airflow from the HY35 in it's factory housing depending on what boost level you're running.

I understand that quickest to slowest spool is- TS hx35>>>bep hx35 >>> hy35>>>>>>hx 35 on t3 manifold.

which leaves me with 2 questions.

How much difference is there between those spool-wise? it's the difference between $200 for hy35 and $450+ for bep hx35

and how much difference between a t3 bep hx35 and a mitsu bep hx35 spool-wise considering same A/R?

 

[pj91gsx]

Very good topic. What is the TS Hx35? The smaller the turbine housing the quicker the spool. The more direct the airflow at the turbine, the quicker the spool and the more it will flow at higher rpm.

 

[hubz91talontsi]

Are we talking about a stock 2L motor?

 

[dacowgod]

FWIW on my 9.0:1 2.0 my HY35 in the stock 9cm housing sees 30psi by 4200 RPM ..and I havent even messed with the AFR's/Timing/Cam gears etc to try to make it spool faster...I'd bet I can see 30psi under 4K if I really tried..

Its been so long since I've had a bolt-on hx35 on a 2.0 car....

the Bolt on HX35 was at 30psi by ~3800 RPM on a 8.8:1 2.4 liter car... with it tweaked as well as I possibly could tweak it.....it had Fp2's ... stock intake manifold, full 3" exhaust etc... It spooled a 56mm 6 blade HX40 in a BEP Bolt-on housing exactly 100 RPM slower on back to back logs w/ no other changes..


the .70 AR BEP T3 HX35 sees 30 psi by 4400 RPM on a 7.8:1 2.0 engine in my buddies car....... That is with HKS264's stock cam gears, stock intake etc...and no tweaking for spool.. . I'm in the process of putting a 8.8:1 2.4 in there so in the next few weeks I could chime back in if i remember to give you spool up characteristics of the .70 AR T3 BEP HX35 on that....

Also FWIW My old 8.8:1 2.4 w/ a .70 AR BEP HX40 would spool 44 psi before right around 4800 RPM..


Please keep in mind though that although all of this info is accurate ALOT more goes into the spool of a turbo.. Exhaust size, restrictions, engine compression, Cam choice, cam adjustment, Intake manifold size, Fuel type, timing, Air fuel ratio... i mean pretty much EVERYTHING you can think of is going to effect the spool 1 way or another so these are just examples.

 

[Ppayer38]

Believe for the extra $250 it won't be a huge difference in spool but I can't speak fact only speculation.

Have you thought about the BigH1C? I k.ow it flows a little less but it will spool crazy fast in a BEP housing from my understanding which is why I picked 1 up for really cheap(can find em for $100-150)

 

[Ludachris]

Seems to me anything bigger than a 16g would be too big for autocrossing. Not to mention you'll be thrown in a class where you'll have absolutely no chance of competing due to your mods - not that that wouldn't happen with the 16g as well, but you'll be worse off due to the later spool. If you really want to autox, you'll have to give up on the idea of big power. There's just no way to have big power AND a good autocross car.

Sounds like you're set on it anyway, but, the title of the thread should probably read - "what's the least laggy Holset turbo for autocross" - since I don't know that there is a "best" option unless they have something comparable to an old GT28R.

 

[TSITurbo95]

^ What he said. Why go with the holset for autocross? I would personally pic a 20g (TD05, ported and clipped) will spool just as quick as the 16g, and flow a bit more air.

 

[ed1380]

It's going on a 2.3l 8.5CR motor. but I'm talking an all variables held equal thing so that anyone can use this info.

A TS hx35 is a stock hx35 but on a divided manifold. TS stands for twin scroll. (it makes turbo's spool much faster)

25psi at 3500 on a stock 6 bolt
Twin Scroll HX35 Response and Street Manners - YouTube



@cowgod - by bolt on do you mean divided turbine housing hx35 on undivided manifold?


@payer- IIRC the H1C is an older hx35 with no surge porting on the intake. If i could find a bep housing I might just do that.

I'm still interested about numbers on the hy35

 

[Tyeler18]

^ What he said. Why go with the holset for autocross? I would personally pic a 20g (TD05, ported and clipped) will spool just as quick as the 16g, and flow a bit more air.

My friend runs a tdo05 20g and it blows for autocross. Way to late of spool, he was lucky to get into boost in 2nd. He's not fully built for autox either, but it wasn't good on his mild bolt-on 1g.

 

[dacowgod]

@cowgod - by bolt on do you mean divided turbine housing hx35 on undivided manifold?


I'm still interested about numbers on the hy35

By bolt on i mean DSM Bolt-On .... i.e. the BEP .55AR housing...

I also mentioned some #'s about the HY as I currently have the HY35 in the 9CM Open Volute housing it comes in in its original form on my 9.0:1 2.0 Liter car... Theres only 1 other HY35 I've actually seen results from and he was an 8.3:1 2.0 Liter car with almost everything else the same as mine and his was only 200 or so RPM laggier...

FWIW I've seen better spool #'s posted than what I just posted but no real LOGS or videos of the better spool #'s to back them up so I cant vouch to say they are not true or not.... And also as mentioned there are a TON of factors that effect spool so Its not impossible to think a a DSM Bolt-on HX35 MAY be able to spool 30 PSI by 3500 RPM on a 2.0 ...but it'd sort of take building the engine around the turbo to make that happen...or getting lucky ... The Twin Scroll HX35's in the 12cm housing and true twin scroll manifolds have proven to spool quickly and have gobs of top end as well though so that may be the best holset in this situation ......Although i've never had experience directly with that to give you first hand knowledge.


.

 

[ed1380]

Seems to me anything bigger than a 16g would be too big for autocrossing. Not to mention you'll be thrown in a class where you'll have absolutely no chance of competing due to your mods - not that that wouldn't happen with the 16g as well, but you'll be worse off due to the later spool. If you really want to autox, you'll have to give up on the idea of big power. There's just no way to have big power AND a good autocross car.

Sounds like you're set on it anyway, but, the title of the thread should probably read - "what's the least laggy Holset turbo for autocross" - since I don't know that there is a "best" option unless they have something comparable to an old GT28R.

Haha I'm greedy. I initially wanted to max out a hx35 and drag race it, but there's no good tracks around here and straight line sounds boring. So I'm slowly coming down from my numbers=everything mindset.

an evo3 16g is around $350 and I would still need a mitsu manifold. a 20g is even more. The car already came with a t3 manifold that's why I've been looking at the holsets.

Wouldn't a 16g put me in the unlimited class anyways? I thought 14b was the biggest you could go without getting pushed up too high. (I have thought about throwing one on just to see how it would be)

 

[TSITurbo95]

My friend runs a tdo05 20g and it blows for autocross. Way to late of spool, he was lucky to get into boost in 2nd. He's not fully built for autox either, but it wasn't good on his mild bolt-on 1g.

Interesting. I run the td05 ported and clipped 20g, and it spools as quick as my 16g did. Anywho, interesting numbers on the spool time of the hx35

 

[Ludachris]

Haha I'm greedy. I initially wanted to max out a hx35 and drag race it, but there's no good tracks around here and straight line sounds boring. So I'm slowly coming down from my numbers=everything mindset.

an evo3 16g is around $350 and I would still need a mitsu manifold. a 20g is even more. The car already came with a t3 manifold that's why I've been looking at the holsets.

Wouldn't a 16g put me in the unlimited class anyways? I thought 14b was the biggest you could go without getting pushed up too high. (I have thought about throwing one on just to see how it would be)

A boost controller all by itself puts you in the unlimited class if I remember correctly, so you're screwed no matter what. But anything bigger than a 16g simply won't spool fast enough to give you the usable power you need when you need it on small technical courses. Full spool by or before 3k RPM should be your target. And even then you probably won't be competitive - you'll need a good deal of suspension mods and tuning, as well as some good tires.

Bottom line, go with any turbo you can find that will spool as good or better than a 16g. Even 500 RPM more makes it worthless for autocross. A 14b or 16g are the best and most affordable choices really.

 

[bastarddsm]

How about an HX30? Really tho, I'd probably just put a 68hta on it, or a EIII16g.

I run a full twin scroll 12cm 8 blade HX35, and it does not spool as fast as they are claimed. I see 30 psi in the 4500rpm range. I used to run an open T3 with what I believe was a 20cm T/S housing. I saw25psi at 5200. Also I lost 3lb/min at 25psi going from the open T3 setup to the T/S.

The final thing to look as it your cooling fans. For AutoCross, your not going to want slim fans, your car will most likely overheat. So you'll need to run the stockers. For a 1g that basically requires a custom made manifold, as none of the one you buy will clear, and I'm told its a challange with the Mitsu-BEP housing as well. You also have a 2g which has a tighter bay than a 1g I believe.

 

[ed1380]

A boost controller all by itself puts you in the unlimited class if I remember correctly, so you're screwed no matter what. But anything bigger than a 16g simply won't spool fast enough to give you the usable power you need when you need it on small technical courses. Full spool by or before 3k RPM should be your target. And even then you probably won't be competitive - you'll need a good deal of suspension mods and tuning, as well as some good tires.

Bottom line, go with any turbo you can find that will spool as good or better than a 16g. Even 500 RPM more makes it worthless for autocross. A 14b or 16g are the best and most affordable choices really.

I'll be honest and say that I'm not looking to be 100% competitive into it right now. Just slowly build it there. Go there when I have time and have fun. I'll be doing this Autocross.dsm.org - Build Your Own Konis I already have the koni yellows.

For cooling it already has a mishimoto rad with mishi 12" fans. Also piecing together an oil cooler/relocation kit.


Even though I'm not going with it, I'd still like to know what's the fastest spooling holset. Others might find it helpful

 

[bastarddsm]

For cooling it already has a mishimoto rad with mishi 12" fans. Also piecing together an oil cooler/relocation kit.

HAHAHAHAHAHA! I had that same setup on my car, it wouldn't keep it cool just running down the highway.

What turbo do you have on the car now?

 

[D's GS-T]

Unless you do everything possible to spool that turbo, it's going to suck on an autox course, especially a small one . I'm guessing the HX35 in the bolt on housing would be the best besides a hx35 twinscroll. Either way I can't imagine a DSM with that turbo ever being competitive unless you have a million dollars in suspension, rims, tires, and a bigger motor everything possible for fast spool e.c.t.

I think you definetly have the right Idea by going out and having fun and testing the waters, but if you want to be competitive some day It's prabably going to lead you going back to a small turbo. It may or may not be fun, depending on if you can get it to spool on the course.

 

[ed1380]

Someday I hope to be doing time attack. Its just not easy for a pig of a car to do good on a small course. Its my mistake for mentioning Autocross. Should have said road course. I just wanted to see what kind of spool times people get with different holset setups.

 

[JusMX141]

If you really want to autox, you'll have to give up on the idea of big power. There's just no way to have big power AND a good autocross car.

Curt Brown would like to have a word with you, Chris.

 

[Ludachris]

Curt Brown would like to have a word with you, Chris.

You can get a LOT out of the 16g if you really get extreme - plenty have proven that, including Curt Brown. What turbo was Curt using for autocrossing?

And for road racing ed1380, you can go a little bigger and be okay if the tracks you'll be running on are pretty fast courses. I had a ton of fun with my old FP 50-trim and the 16g before that. I'm thinking I'll have just as much fun with the new ball bearing HTA76 when I finally put it on.

 

[JusMX141]

You can get a LOT out of the 16g if you really get extreme - plenty have proven that, including Curt Brown. What turbo was Curt using for autocrossing?

I know he started with the FP Green on his blue Evo, then moved to the Red...and I'm pretty sure he's on to the Black. The ultimate goal is a 9-second auto-x/road race car.

 

[ed1380]

Well I listened. Real E316g for $200. Has some thrust play but the seals are still good

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Supposed to get the rest of the car tomorrow if he calls back. 98 gsx auto missing a longblock.

 

[snowborder714]

Glad to see you took everyone's advice


I have a 7 blade HX35 that I plan on installing with a TS manifold, so I'll post up how it does in an autox once I get around to it, just for some data.

 

[JusMX141]

Well I listened. Real E316g for $200. Has some thrust play but the seals are still good

Rebuild it before you use it.

Thrust wear gets worse rapidly, and there's not much tolerance between the wheel and cover for in/out play before you're dealing with wheel damage.

 

[ed1380]

I'm still keeping the holset. I might get the twin scroll t3 next group buy

Glad to see you took everyone's advice


I have a 7 blade HX35 that I plan on installing with a TS manifold, so I'll post up how it does in an autox once I get around to it, just for some data.