Martin Wonnacott has done I think 515bhp on a 2.5ltr with a very similar housing mod to yours on the very same turbo. Seen 2ltr in the USA hit 600, but different story with 2.5s.
good to see the Hy will support an extra few poneys if it came about. why are people so hatred over the HY, would a HX35 make any difference over the hy on the 2.5.
Unless your engine is massive, you want over 500bhp, or you got a twin scroll setup, a HY is better IMO. HY is proven at 600 on a 2ltr. Over 500 on a 2.5ltr. And just remembered someone did over 500@wheels (so maybe best part of 550) on a 2.8 V6 with one. Most I've ever seen on a HX35 is 600bhp, quite a lot of times, on 2ltr. On a massive engine a HX is better as the bigger turbine will choke a lot later, but on 2.5ltr or less, HY wins every time in my eyes.
Finally dynod it! Stock RB26 with CBX Exhaust mani, HY35 with chopped Ex Housing and 106mm downpipe, 2 Tial MVS Wastegates (before i had a twinscroll setup), Selfmade Triggersystem, Audi Ignition coils, Siemens 750cc injectors, 12 litre oilsump, selfmade crankcase-vent. Results: 470 HP and 600nm at 1,3 bar 1,3bar and 600nm at 4000rpm in 4th on the dyno, 1,3 bar in 4th at 3300 on the street Wanted more boost, but with 600nm my clutch has reached its limits. Unbeliveable boost response over 3500rpm in 4th: Drove with 4120rpm, tps:0%, MAP:-0,7bar then hit the throttle, tps:100%, 1,3 bar at 4500 3500rpm, 0bar, tps:25%, then throttle to 75%, 1,3 bar reached at 3800rpm Response and the sound of this turbo is brillant! Holset Super HX40 with the same setup made 510HP ar 1,3 bar, but wasnt by far that responsive or that quick on spool! Great! It still isnt a normaly aspirated 7litre v8, but it is very big fun to drive!!
The HX they have on there is one of them funny turbos Holset call a HX but isn't. Look at the wheel sizes, it's what you'd normally call a HY35 or HX32. Much smaller than usual turbine wheel. Should be amazingly responsive, can't believe it's not sold, if I had a use for it I would have it, looks bang on. Brilliant, awesome results for such low boost! HY35s and related turbos are ridiculously good turbos, makes way more expensive turbos look like crap.
Hi guys! Had a good look through and got a rough idea on the do's and donts with holsets and i want one to go on my rb20. I need to get a rough idea on what i actually need spec wise so i can save up and keep a eye out for one. So rb20det with metal head gasket and arp head studs, not sure on what kind of boost it will hold 1.5 bar id have thought? Manifold wise im going to go for a topmount manifold from japspeed/ebay and see how that pans out. Turbo i want a holset as they seem pretty bullet proof and bad ass, But i need some advice on which one to suit my spec. Im aiming for 350-400hp so i don't need anything to big. Would a Hy35 be suitable? Or say a hx30 with small housing. Obviously being only 2l theres going to be some lag but of course the less the better. Would have at least a 3" downpipe and external wastegate (38mm?) Cheers
You'd want the HY35W. HX30Ws won't do 400hp on account of their very small compressors. There are a few variations of HX30s, and even the biggest would just about scratch 350. The compressor/turbine is not very well matched for gasoline applications. Plus, they are also very rare, you'll more easily come across some HY35W variant. Stavros runs (ran?) a very HY35W-like unit on his RB20, and reports good boost response, on internal gate, IIRC. But again boostresponse/lag is also dependent on the tune and is also somewhat subjective to the observer, so YMMV.
I ran external gate. I had positive boost by 2750, full boost by 4k. And 470bhp at 1.5bar on a stock head and cams. But my setup was good. HY seems overkill on a 2ltr for just 350bhp+ to me unless you find one with a rare as hell 7/8cm housing, which isn't likely. Granted a HX30 maxes out about 350, but the way they spool (with the right spec one) and the torque they make on a 2ltr (a few on here have ran them) would likely make them more fun even at 330 than a bigger slower spooling turbo making 30-40bhp more at the top end. But you'll struggle to find a 30, as mentioned.
Thanks for your input guys. Stav i hate to be one of those people but what turbo would you recommend for my setup? Im not 100% sure on what power my engine will take, id have thought 400hp would be pushing a relatively stock engine. Also am i right in saying a small turbo with a lot of boost will perform better then say a bigger turbo with less on a 2.0?
Hey Stavros, i want to swap my 1JZ out for a 2J VVTI with forged rods, new bearings, aftermarket cams etc. What do you think how a HX52 11cm will perform? Will the housing be too small in the upper RPM?
"Perform better" is a very subjective term. What does that mean for you? Fast response? Wide torque curve? Peak HP?
SRS- Yes, quicker spooling turbo and more boost almost always makes more torque and a bigger powerband for any given power level than a bigger turbo and less boost. Only times I've seen different is when people have gone from Garretts to something more efficient like a Holset- Some of the peak torques people on here have got with stuff like HX30s and HE221s even at fairly low boost is pretty nuts. Ref what to do on a 2ltr 400bhp engine, well personally I think 400bhp is a wierd gap shitty level for Holsets, ie none of the common ones do it. If 350bhp, then a HE221W or 7/8cm HX30 would be ideal, but there's then a big jump to the next commonish ones, which are 9/10cm HY35s. In an ideal world I'd be getting a 7/8cm HX32/HY35 (seen the same basic spec called both) but they're rare as hell, so not likely. And because of that, if I wanted 400, no less, no more, im not sure I'd end up with a Holset as they rare to come by. Sulik- Considering the very large turbine wheel on the 52 I honestly think it will be perfectly ok. HX52 16cm (not using a twin scroll manifold) seem to be at full boost under 4000rpm on a 3ltr though, so even a 16cm would be fine.
Yeah more responsive. Im not really into chasing numbers, I just want something thats responsive with a bit more punch then stock that will pull all the way to redline. Im now thinking a good rebuilt turbo on the standard manifold would be more suited but i really don't know as i don't have much experience in turbos
If you want 300bhp max, yeah, stock turbo isnt bad when done right. On my RB20, stock turbo mightve spooled up quick, but it was dead by 6k or so, and wasn't very fast. The next turbo was a GT2871, which spooled up almost as quick, was dead at similar revs, but at least was 300+ The Holset, while wasn't spooling as fast, had much more torque even by just over 3k (despite less boost, 7psi by time 2871 was at 15, but a lot more efficient), was monsterous from 4k to 8k, and had 470bhp. So the bigger turbo actually had a bigger powerband (4k worth rather than about 3k), at least 100lbft more, and 150bhp or so more.
Quick question. Is this the standard oil feed to my Holset HY35? Getting ready to start making the oil feed and want to use -4 but this is apps rely bigger. Is it just a case of replacing it with a -4? Thanks
Personally I'd use a -3 and no restrictor. That seems the best way. Don't use the thing you see there, no need. Fitting direct to turbo is 12mmx1.5
Nice one that was my next question. Yea I've decided against a restrict for time being as can fit one if needbe rather than risk fitting one now and kill the turbo. Was just concerned a -3 might be too small. It's for an RB25 if that matters? Still recommend a -3 Stav?
