juggernaut1

Old 44 vs New MVR 44 http://www.titanmotorsports.com/ti44mvrwa.html When AUD$ was stronger I had two delivered to my door from the US for around $842.18.....that equates to approx $421 each.....which in my mind is a bargain compared to our local offerings.....especially when you have to buy two Lol. Apparently, word is that Tial are also in the process of making their smaller 38mm MVS with the water cooled option as well.

I'm guessing yours is still a way off?

Well I have received the extrude honed ex housing and just received a pair of the new Tial 44mm MVR watercooled gates and a few other bits and pieces. I needed more room with these shorter gates to fit in the 3.5 inch dump.....and the good thing is that these will fit straight onto the existing flanges/setup. I'll drop the gates off to C-Red tomorrow. Then its in their hands.

Yes I get it now...I was thinking that when they are on the same side the battery also supplies a current to the alternator and therefore the ignition system when the car is not running - i.e. the alternator is still live because of the battery. However, on closer inspection of the diagram link I posted, this is irrelevant because the live feed from the alternator to the fuse box has been cut and removed and replaced so that it is effectively running off the other side (non battery/alt side) of the isolator switch. So all the alternator now does is charge the battery and is no longer used as a source of current to the ignition system or any other electrical system of the car as this part of the system has been removed. I now confirm that the principals in the electrical diagram in the link I posted is correct

Doesn't the isolator switch need to cut power to the alt so that the car stops dead when you flick the kill switch.....if that is what you are trying to achieve? In you latest diag this won't happen and the alt will keep powering the ignition system and therefore the engine will keep running when the kill switch is flicked. In your diagram the kill switch will only prevent the car from starting....but not stop it from running. Scroll down to post #9 http://www.ls1tech.com/forums/drag-racing-...off-switch.html Shouldn't the fuse wire in the attached diagram link terminate on the other side of the kill switch - as it is its terminating on the same pole as the battery cable therefore providing power to the alt. Now I'm confused Lol.

ATP housings aren't well finished compared to the Garrett offerings.....assuming you can get the Garrett equivalent or at least an ATP modified Garrett (for example the GT32 T3 .78). From memory based on what I've read on other forums, ATP use a sand casting method for there housings. For comparison purposes an old .82 Garrett I had lying around with weld on 4 bolt flange.

I can't see the beer fridge or plasma.

I think it was Geoff Raicer (of Full-Race fame) who once commented on a forum that torque starts declining when ex manifold pressure exceeds intake manifold pressure in a turbo setup. I guess this makes sense as it is at this point the VE would start declining resulting a drop off in torque and therefore hp. Hopefully the decline doesn't happen too rapidly resulting in a short torque/powerband. The aim of the game is to get torque to build as early as possible and hold it flat to the redline - easier said than done with smaller responsive turbo's.

When you said 6000rpm I assumed you meant steady state.

A car in 4th at 6000rpm going downhill, depending on the decline, is likely to be producing vacuum not boost....or have I missed something?

Looks like the hypergear turbo is a great street turbo.....unfortunately the turbo (any turbo) can't be all things to everyone.

Agreed turbo's like to be loaded because of there inherent lag. A big turbo in 1st gear will not be able to keep up with the flow requirements of the engine. Once a taller gear is selected the engine revs slower and the big huffer is in its element because the compressor has a chance to come up to boost earlier in the rev range. This is why ramp rates of dynos can skew hp figures. As an extreme example listen to some of those 1000hp youtube dyno's.....they rev the engine to what sounds like around 5000rpm and you can hear the big turbo coming up to speed, and then once up to speed (or loaded) they then do the dyno run.

Can't say I've seen too many (any) DD's using a ramp rate of 13.

Any reason why only 17 psi Trent. I know when I ran 15 psi through my 3071 on an SR it was fairly lame......when upped to 22 psi it was another story

Here's another link re exhaust systems.....as they relate to WRX's....... but may have applications to turbo cars in general. http://www.msengineering.com.au/exhaustsystems.html ...and a couple of interesting quotes from the link on the matter of using bends and smaller tailpipes in the system to help midrange. Using an S bend leading into the rear muffler via 2 90degs back to back offers the most torque in the mid range, reducing the angles from 2 x 90 degs to 45 degs moves peak torque up through the rpm, using almost straight pipe with angled muffler provides and very linier power band, smooth delivery of power with no "kick" as a result from noticeable losses in torque in the mid range. The S bend has a huge bearing on torque in the mid range, after consulting with Prodrive they verified this for me, a straight pipe might see more top end power, but the loss of low down out weighs the gains. Also changing the rear tail pipe section from 3" to 2.5" helps torque, using 2.5" rear mufflers greatly help mid range with gains on WRX/STI set ups. Pressure at the turbo is not effected with this and helps to keep gas speed up for better power.

I think I found more of the details and pics on another forum....it appears as though he is using a Greddy exhaust manifold (refer post 1 & 6) So in summary it sounds like a twin scroll housing on a single scroll/single gate exhaust manifold....lol? http://www.freshalloy.com/forums/showthrea...ght=twin+scroll

Unfortunately I can't offer any more details on the setup as I plucked it from another forum and the details were scant. I only posted what details I knew. Here's the original thread link. http://www.nissanroadracing.com/showthread...1055&page=3

For your reference .....twin scroll T4 GT35 1.06 rear on RB26 at 20psi.

Yes his comments also disagree with the real world on the dyno findings too in relation to WRX's which is what his comments were aimed at....although I suspect he's generalising and applying that to WRX's.

Port shrouded 3071's are available through ATP turbo's ...just click on the option when ordering.....might be a cheaper option than the HKS variant.

Some of the WRX owners are fitting smaller diameter tailpipes to their aftermarket exhausts and the dyno's they've been posting up are showing reasonably more mid-range and nominal peak hp loss. Gas speed is higher where they are at their hottest...immediately post turbo...and cool down from there...... resulting in less flow requirements as the exhaust progresses. Also scroll down to the part: Can a free-flow exhaust reduce efficiency? http://www.max-boost.co.uk/max-boost/exhaust/exhaust.htm

Only prob with variable vanes turbos is the increase in heat in the turbo from around 700 to 1000 degrees in petrol applications. Porsche use some fairly exotic stuff to keep the turbo together. Diesel applications run at much cooler temps and so exotic materials are not needed in this turbo format. Nevertheless it would be awesome if variable vane turbos became commonplace in the aftermarket turbo world.

If going for the 200sx split pulse I would go the T3 version.....the T4 version has a smaller turbine inducer and exducer for some (ill) logical reason yet the T4 is supposed to be rated for more hp?

Here's a couple of pics for a sr20 using the above "dual plenum" concept.

Any development in turbo's is likely to come from from the manufacturers for numerous reasons....in order to meet lower emissions / make more power from smaller capacity motors / improve VE of an engine to reduce fuel consumption, etc / plus they have a ready market by equipping their cars with turbos.......as is evident in recent years with a resurgence of the use of turbo's in production cars. Garrett and others couldn't care less about the above factors, and so I can't see any great inroads made by aftermarket turbo suppliers in turbo technology.