Alternative Turbos similar to an RS2 ?

[macspring]

Post (# 77) by Jamo in this thread - http://www.s2forum.com/forum/showthr...t=43612&page=1

a stock k24 can hit 300 bhp, with the rs2 manifold, a bigger intercooler and high boost you could hit those figures

but

a) high EGT's
b) compressor is way outside it map
c) shortened turbo life
d) why pay the money for oldschool kkk technology when garrett / ct / precision ball bearings are out there

Hoffer is changing the compressor wheel, if it's more efficient then you could push near the 315 bhp on paper although hotside is always the limiting factor.



What I was curious about was what models of the brands Jamo mentioned, (garrett / ct / precision), would equate to an oem RS2 turbo - K24 7200 ?

Also any links to reputable companies who can supply the turbos people suggest ?

Hopefully this query only starts an informative discussion and no rows.

Thanks either way for any feedback.

[Mcstiff]

Volvo uses one that is slightly bigger (K24-7400).

[macspring]

Mcstiff,

Thanks read all of the threads that relate to K24 7400. Not quite a bolt on just yet.

Interested also in the three brands mentioned, and also the Turbonetics brand.

Kind regards.

[prj]

So if the K24-7400 is not bolt-on, how are the Garrett Turbos bolt-on?
If you want true bolt-on, your only choice is K24-7200 or K26/K27 hybrid.

[macspring]

Prj,

Point noted, but any feedback on others that are a relatively easy install, compared to a true easy bolt on ?

I can't weld or fabricate, but I can work a socket set, or order the relevant part if someone else makes it / sells it.

Thanks.

[Ross]

I'm still waiting to see PRJ's estimates on the volvo turbo once he's done a good mapping session with it fitted... it looks like the perfect 350hp turbo to me, question is whether it will push 370-380 and how long it'll last at that... 350hp is not enough on an RS2 IMO :mischeif:

I know where you're coming from David - an equivalent to hoffer's hybrid K24-7000 on the RS2 would be ideal. Near-stock looking, stock location. No engine mount spacers, DP modding, custom intake hoses etc; i want KKK with the same stock fit as my MD147 and same 380hp but peak torque 500rpm sooner...

Funny thing is, the answer may be as simple as refitting RS2 cams (from 7A) and a stock RS2 turbo

[Rusty]

Hoffer also does turbos that are equivalent to 'RS2+', best to ask him about them.

[prj]

I mapped a K26/K27 on a 2.3L mini-stroker recently with 8.5:1 comp ratio, ported head, tubular EM, 3" turboback exhaust and big FMIC. 7A exhaust cam, AAN intake cam.
I don't have dyno graphs but I have some datalogs.

IIRC full boost was 3600 RPM 3rd gear and 3100 RPM in 6th.
Shell was UrS4 Sedan.

Boost was 2.1 bar spike, taper 1.5 @ 7000. I maxed out both the turbo and the 440cc injectors at 4 bar.
Duty up to 92%, turbo started to blow hot air over 1.5 taper...

[prj]

Correction:

full boost in 6th gear @ 2900 rpm.
full boost in 3rd gear @ 3600 rpm.

Keeping in mind it has a slightly larger displacement and tubular EM - I'd say this is a bit laggier than RS2 turbo. Much better top end though, but it's still a midrange turbo.

[Costash]

Hehe I think I will go for a hybrid made by Hoffer al day long!!!

[Dan]

Has anyone got any dyno results from the Hoffer hybrids?

[Ross]

Dan - there's Nip's thread with the Hoffer K26/27 420hp hybrid. Ran 396 hp on 95RON with peak torque around 3800rpm IIRC.

prj - that's interesting; I could live with that. I'm seeing peak torque at 3900 and peak boost @ the same in 3rd, around 3500 in 6th. Need a head rebuild, so perhaps some efficiency improvements on the head and bin the 7A inlet cam on my k26/7 will get me closer. I was hoping to change the tubo at the same time though, but if I'm not certain on what to go for we'll have to see.

[prj]

Ross, remember that engine was closer to 2.4L in displacement, so it spools quicker.
It spools almost as fast as my K24-7000. That gives 1.65 bar at 3300 rpm in 3rd gear.

EDIT:
Frankly, if you want 500 rpm earlier peak torque, you'll probably have to get that Volvo turbo.
As for various hybrids - I don't understand the hype. Numbers on a single dyno with unknown correction factors - without other cars being on the same dyno - I'd take that with a grain of salt.
K26/K27 hybrids will give you peak torque at ~3800-4000 rpm. This is laggier than a RS2 turbo, which is normal, since it makes more power. This is where other cars I've mapped with K26/K27's made their peak torque. This one was better due to tubular EM, 3" DP and of course the larger displacement.
If there is a magic turbo out there, then it's the newer ones, such as HX35, GT3071R, K24-7400. Not recycled 20 year old technology.

[Costash]

You just don t get it lol.They have 360 on them which is fairly new tech.The dyno day in July it is the day wen they(hybrids) gonna prove.Till then.....

[prj]

You just don t get it lol.They have 360 on them which is fairly new tech.The dyno day in July it is the day wen they(hybrids) gonna prove.Till then.....

Again more hype. Wheel design is much more important. A turbo with more efficient wheels will outspool and outflow old designs. The 360 bearing does not have much to do with performance, it's for reliability.
It has been known for at least ten years, that a K26/K27 gives you close to 400hp with full boost at 4000-ish RPM in third gear. You trade lag for performance. That's normal.
And while the K26/K27 is a good turbo, it is no "magic turbo". The new Holset and Borg-Warner designs are much better.