juggernaut1

I agree with all of your comments. I have a Turbosmart raceport bov on my car and its crap. Firstly there is no spring tension adjustment on the BOV (which I found out after buying it)....so the only way to adjust them is with a spring kit......so I bought a spring kit and tried different springs...basically its still useless as I either get surge on a stiff spring or it won't close on idle with a weaker spring. Having done a bit of reasearch in the past I decided I was going to get a Trust Type R bov becuase of its valve design......and now the Evo 9 Bov sounds promissing too.

Beautifull.

It may not be as simple as cutting off the collector and welding on a split pulse collector as the runners would need to grouped in such a way that each exhaust pulse fires into the correct side of the split pulse collector i.e. based on the firing order of the engine, each alternate exhaust pulse must fire into the opposite collector - otherwise high exhaust back pressure in the collector will be the result. Therefore, you would need to examine your firing order and exhaust manifold runner layout and firstly confirm this.

Tried GCG?

Yes I remember him calling it a "monster" in some of his posts. So it sounded like it had a huge mid-range.....which wouldn't be kind on the weak SR drivetrain.....not that drifting would be kind on any drivetrain

Out of interest Dane, you might remember "_omg" from NS.com - his drift car was reportedly putting out 315rwkw's with a 3071 on a 2.2 SR. "Full boost" was under 3500rpm from memory with the open housing.

Thanks Lithium for that link re s256 vs 3076. The following spec's are lifted from that link: Here are some measurements I took of the turbos: Borg Warner S256: .50 A/R compressor housing Compressor Inducer 56.0mm Compressor Exducer 85.95mm Turbine 75-76mm (odd number of blades couldn’t put a caliper directly on it just a ballpark figure) Turbo with .70 A/R 4 bolt housing: 21 lbs Turbo with .85 A/R 6 bolt housing: 23.2 lbs Garrett GT3076r Compressor Inducer 57.0mm Compressor Exducer 76.14mm Turbine 59.90mm Turbo with .63 A/R 4 bolt housing 15.0 lbs Turbo with Tial .63 A/R v band stainless housing 11.2 lbs Now I just had a look at the BW S200 specs and this is what I find (based on my conversion from inches): Compressor Inducer 56 mm Compressor Exducer 80 mm Turbine Inducer 74 mm Turbine Exducer 65 mm So my earlier suggestion that the S200 = to S256 (based on comments from Geoff) are not correct unless the specs on the 256 have changed since the tests in the above thread link were done. Therefore, compared to the S256 (in the above test with the 3076) the S200 has the same comp comp inducer and a smaller comp exducer by around 6mm. In other words the s200 has a smaller trim comp wheel with what would appear to be the same size exhaust wheel of the S256. But the s200 still has a bigger comp and possibly turbine wheel than the 3076. So the S200 would be a more responsive turbo compared to the S256 and then add twin scroll on top of that and it will be more responsive again. More responsive and power productive than the 3076 in TS format...quite possibly.

Geoff suspects the 74mm T3 turbine wheel is more efficient than the 70mm T4 turbine wheel. So T3 sounds the way to go.

Geoff Raicer re the s200 = s256. This turbo can be spec'd in single scroll (with traditional or misubishi ex housings) or twin scroll. I think there are two ex a/r in the twin scroll with .85 being the largest. From memory the BW has a bigger ex wheel than the 3071/3076 too. Late clarification: the s200 is the twin scroll version and the s256 is the single scroll version..... just different naming for the same turbo but with different ex housings.

Dane, I think you've sort of answered your own question. Choose TS 3071 with .78 for the best transient response turbo. I can assure you it will haul out of corners and give you good a broad rev range. You still need a delicate right foot out of corners but it has a nice linear power curve which makes the car controllable, predictable and best of all easy to drive. Think of it like driving a n/a V8. If you wanted more power than the 3071 I would go the TS BW200 (which is actually the BW256) over the 3076 with the TS .78 A/R. Looking at the compressor map IMO you will make more power out of the BW 200 over the 3076 as it flows a bit more air and is also more efficient at higher boost levels if you wanted to turn up the wick. URAS: thanks for sharing the various dyno's as well. Disco: No rose coloured glasses here re the SR20.....but still not a bad little package.....although valve train could have been better.

The only problem with the 3076 TS is that the .78 A/R TS housing is becoming challenged for flow. Hence this is the reason Geoff Raicer is recommending the 3071 to Dane (as he recommended to me) as it provides the best transient response but also the comp flow is more compatible to the ex housing flow. Users of the 3071 setup that have switched to the 3076 setup have reported more mid and top end, but its not mind numbing but "noticeable" from the seat of the pants feel as reported by those who've done the upgrade - although I have yet to find a back to back 3071 and 3076 dyno comparison with a TS .78 AR ex housing - I might be the first. Due to the limited TS ex housings for this size Garrett turbo (although I did manage to find myself a used .82 TS A/R) - I suspect this is the reason Geoff is now recommending the BW turbo's as the GT30R equivalent is available with a .85 TS A/R. As for traction - I'm running 290rwks (TS 3071) with sydneykid suspension coilover kit on my s15 and I'm impressed with the way the car get its power down from 2nd gear on with the TS setup - however, I suspect the short runner Hypertune intake might be dulling the mid-range and so help traction in this regard, whilst extending the rev range.

Oh OK

BW S200 dyno vs T67....perhaps the Borg Warner may give you the mid range your chasing. and source: http://www.turbo-kits.com/s200_turbochargers.html

He's a blurb I found on the BWs200 vs T67...scroll down the link: http://www.turbo-kits.com/s200_turbochargers.html and dyno comparison

GTK 550.....full boost at 6000rpm.....90rwks by 5000rpm and then hang on!!

Disco, the Evo that took out the last Super Lap had something like 550rwhp - OK I realise its 4wd - but who would of thought a TO4Z strapped to an Evo motor would be a force on a circuit and actually bettered Mark Berry's new R34 by about a second from memory .....ahh yes the EVO had a Full-Race twin scroll manifold tho'. Also Dane's is stroked to 2.2.

I think you could throw a TDO6 L2 in the list of potential turbos too for your power output. Although I do like the twin scroll turbo setups as they exhibit a more linear power curve than some turbo seups which will potentially result in a faster circuit car.

Not an RB25 and not a T67, but on an RB26 Brockas switched from twin 2835's to a single GT35 and picked up substantially more mid with a tad more power earlier. From memory he used a GT35 with a T4 turbine housing which he got through GCG turbo's. He posted up a thread here in SAU not so long ago.....here's a link to the dyno on Antilag....scroll down to his dyno nearly half way down the page - he was making 165rwhp at 4000, 275rwhp at 4500 and 557rwhp at 6500. Also search on SAU for his thread for more info. Notice how the torque peaks at 5000 and holds fairly flat to 7500 which is the sign of a good turbo match. http://antilag.com/forums/showthread.php?t=749&page=54

Oh well......Lowndsey and Whincup got 5th...clearly past their prime.....good riddance I say. Holden can have Fevola too .........sorry wrong sport

Nice of you to give them a head start. PS why is the sky so hazy.....nuclear fallout I suspect

True, but they are trying to make engines more efficient. Longer runners = more torque in the rpm range where most people drive. More torque = more efficent engine. Longer runners = less peak hp as a generalisation.

I've thought of the change in runner length too. However, wouldn't manufactures have lengthened the runners by the thickness of the spacers (ie. around 3 - 5 mm) if the gains were attributed to just solely the change in runner length?

I like better mid range and throttle response in the rpm range where 90% of my driving is done.....particularly when bigger turbo's are fitted. Area under the curve is more important to me than peak hp. But hey I'll take both mid range and peak hp if I can get them. I run one of these spacers on my SR....and on a 36 degree day after 42 dyno pulls the intake manifold was only warm to touch. A side benefit is that the fuel rail also gets less heated (as heat transfer from the intake manifold is reduced or at least delayed) so your fuel temps would also be cooler. I didn't do a before and after test because a myriad of other changes had also been made so I can't quantify any specific gains (or losses). At the end of the day the cost of the spacer was insignificant compared to what else had been spent on the car - there were no apparent downsides that I could see - so I installed one. I even contemplated stacking two together however, my studs weren't long enough and the intake side of things was getting tight in the engine bay as well even if I changed my studs. It may only be minor percentage gain....but if you can couple that with other minor mods you may just end up with a noticeable difference in the end.

Taken from outlawengineering.com. Notice the trend that the hp and torque diminishes as rpm increases supports my previous suggestion that the spacers are most beneficial in street cars. As rpm rises and air speed through the manifold increases and the potential for the air to grab heat is reduced - the two graphs merge. Its at low/mid rpm and stop/start traffic that they will be most beneficial when the air speed through the plenum is lowish and more susceptable to heat soak.