RS2 Competition Turbo

[Albert]

It gives nice everyday power from 2k up but real fun starts bit later.

Hope you have your turbo with smaller turbine housing or it will have lag.

What A/R would You recomend for 2.2 with GT3071R ?
0.63 ar, 0.82 ar, 1.06 ar ?

I want the turbo to spool up early and have around 450PS in the top end. I'm thinkig of 0.82 ar.

[kalsket]

I'm running 0.63 turbine on my GT2871R, tried 0.82 and it had much later spool up. Current setup gives around 440PS.

[Faheemo]

I've got the .63 Ex housing on my turbo.
Downpipe Should be ready this week sometime.
Hoping for Full boost at 3000Rpm we'll see.

kkk24 on the left.

[Faheemo]

heres my 3071 .63ar connected up.

[Jamo]

heres my 3071 .63ar connected up.

Thats better external wastegate!!! none of the internal bobbins

How does it boost?

[4WheelDrifter]

I would say not very well, by the look of that hose.

[Faheemo]

Nope thats not the final install still got to sort out all the hoses.
Havent started her up as yet, just got the downpipe back from a ceramic coating, and all the heat shields to go back on and boost pipe to throttle body.

[Jon441cc]

heres my 3071 .63ar connected up.

Faheemo , did you get your GT3071 from 034 motorsport ?

[S4-Sleden]

Im thinking of switching to GT 3071 myself......thinking of selling my K26/27 or KX 450 as its called. I want boost as quick as early and the GT series looks very tempting!!!

[Faheemo]

Turbo is from ATP Turbos.
KKK Flanges on the turbine side, no internal wastegate.

Tried to start her up this afternoon but had a few electrical gremlins.

[Ross]

Back to the differences between the two turbo's... here's a little 'on the strip' comparison between the 2, from 1st-hand experience:

Ross,
As both RS turbo's have the same #6 hotside and the coldsides not being greatly different it would follow that they "should" spool very closely. This is exactly what I observed in both cars. Any difference in low and midrange will have to be detected on a dyno cause none of my datalogging showed a difference.

Where they were different was up high where I've observed and logged the RS2 dropping off as much as 5 psi above 5500 on a hot day, from 26 to 21 psi. The RS2 Comp on the other hand would hold 26 psi to almost 6k before falling off to about 23.

The high end difference only showed up on the 200q20v as the 10v car isn't tuned as heavily and didn't have datalogging capability until later. On the 10v car we couldnt tell a difference between the two. We were using 1/4 times and speeds and they were so close as to be easily accounted for by driver induced errors.

What does this translate to in the real world? A friend has a wicked little 86 300zx street/strip car, basically a stripped chassis, a few more pounds of boost, side exit 3" exhaust. Head to head with the RS2 on the 20v and an open exhaust the 1/4 mile difference between the two cars was within a few thousanths...which car won depended on which driver made the better run. With the RS2 Comp the results got lopsided. He was still chasing me down but the 200 was always a few thousanths quicker.

We are basically talking about a fender length difference in the 1/4 between the two turbos on the strip.

I suspect there may be a noticable difference in heatgain between the two on a roadcourse for most cars. I wasnt able to detect any but thats probably due to the huge FMIC on the 20v.

Hope this helps

[Jamo]

Back to the differences between the two turbo's... here's a little 'on the strip' comparison between the 2, from 1st-hand experience:

That's an interesting article Ross , the problem comes i've seen the price of a new 7200 competition in america

Can you ask the guy who wrote that, which flavour of RS2 comp turbo it was?

The one with just 2.7 compressor wheel or 2.7 compressor wheel and compressor housing +1 from RS2 unit?

[Ross]

Jamo,

The comparison the bloke posted was the regular RS2 vs. RS2 'comp' (one with only the wheel changing - the 2772 opposed to 2672 - i think the housing is machined slightly for it to fit?). Don't know much about the +1, so any info would make an interesting read. I trawled about the 'net sending a bunch of emails to get some real-world comparisons between the two!

Cheers
Ross

[Jon441cc]

RS2 Comp

http://www.bufkinengineering.com/turbo.htm

http://www.bufkinengineering.com/RebuiltK27.htm

Good read

[Ross]

#6 hotside...same as the RS2 Jon. Just done a bit more reading, and I'm a bit confused - i think the "7200 comp" has the housing and wheel changed, and then some ppl have engineered their own by machining the rs2 housing to fit the 2772 wheel - perhaps you know a bit more Jamo?

At the end of the day, the hotside is the limitation - i've heard the comp. has slightly higher efficiency at higher rpm, and therefore delivers full boost ~500rpm closer to the redline. Works for me but not really worth much extra cost - if you're gonna splash out, seems the 3071 is the way to go.