Why not email them mattz? sales@gcg.com.au You should also try UAS sales@uniqueautosports.com they deal with GCG alot and when i was shopping around offered a better price than i could get direct
I suspect that I will get a better price going to zx2nv and at the same time as they are trying to launch their new kit to our market. If they can cater to all of our members, then they'll surely get a better rap cheers
$1200 each turbo for the GT2860R turbo with silicone hose fit front comp cover. Shipping would be an additional $40 to you. Might be able to do a bit better in a few weeks once the kits come on line.
Thats a pretty decent price Graeme is that the GT2860R if so very fine RRP now is around the 1380 mark per turbo
Heres the old thread. A lot of the questions you guys are posing and try to answer in this thread where bounced around heavily in the old thread. Have a look, Its quite a few pages. The old graph links are still valid as I still have them in my photobucket. http://www.aus300zx.com/forum/showthread.php?t=236468&highlight=gt28r
They has actuators on them but they where big Mofo's that wouldnt fit. I still have a spare if you want em. You had to buy the HKS upgrade whihc at the time was USD $165 plus postage. AFAIK the actuators even now on the GT28R's is the big bastard. You may want to clarify that.
Cool will do I just printed off your exhaust velocity calcs and will check them against my calcs when finished. There is a fair amount of difference now compared to those older graphs the now GT28RS has a very safe surge zone whereas the GT2871RS has a lean surge line similar to the original GT28RS map you have in the thread. Its interesting how far they have come in a short space of time.
can you explain the difference? like the difference between the old GT28RS and the new 28RS, arent they still the same turbo? getting confused over the different terminology especially since they changed the naming conventions.
The change in the garret maps for the GT28RS came about the start of 2006. I suspect they had some issues with people using the upper end of the graph at around 30 PSI and they had to replace a few turbos. They then redid the maps and republished new ones that didnt extend quite that high. There was a lot of discussion on TT net as to why they did this and also if the earlier graphs where still valid at high boost. Here are a few TT net links that have usefull info you may want to look at for research purposes. The first GT28R's fitted to a Z32 http://www.twinturbo.net/net/viewmsg.aspx?forum=technical&msg_id=910811 This link is one you should really read and digest. Its from Greg Dupree and basically talks about the capabilities of the Gt28R and RS. But the interesting point is the discussion on maxing out the turbo airflow, and how more boost is not neccesariliy the be all and end all. http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1656975 http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1658653 http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1658744 This is where I get my preoccupation with air flow through heads, cams manifolds etc. Its only when you remove all restrictions in the air path that you can max out turbos. You can max out turbos like the GT28RS at 18 PSI ( so that boosting further gives you no more power) given the correct head mods etc.
They would have changed something to have a different map wouldnt they or did they just alter the map so people would select a larger turbo to prevent the smaller ones from overboosting and causing damage so basically they moved the choke line to cover there back sides??
They didnt change the turbo. In fact all they did was regraph the chart. The explaination they used was that they made a "higher resolution" graph. But notice they conveniently stopped the new graph at a much lower boost level. There is actually a post from Garrett explaining what they did. But I didnt book mark it. I (and many on TT.net) suspect this was due to high boost level turbo failures. In a well designed and implemented z32 head,valve,cam and manifold upgrade. You should not be able to boost the RS to above 18-20 psi in any case. To go further will only generate heat and not more power.
Do you mean difference between GT28RS and GT28R, the S on the end means its a slightly higher flowing turbo.
Hi Tekky What calcs did you use to come up with the flow calcs per 1k rpm back on your chart. My prelim figures come out slightly higher at 15psi at 2k i get 90.73cfm per turbo or side at 3k i get 136.1cfm per turbo at 4k i get 181.47cfm adn so on all lower than your calcs Can you remember all the basis points for the calcs like the VE IE AT AFR etc etc Also thanks John@Z1 will be great to get some keener shipping sorted for this market it will bring more sales me thinks
A Laggy topic and explained very well What is turbo lag (and how do I avoid it)? The majority of turbochargers feature a wastegate--a valve which allows some of the exhaust gas to be directed around the turbine. This allows the turbo's shaft to spin at a reduced speed, promoting increased turbo life (among other things). Think of it as a 'stand by' mode. Since the turbo isn't needed during relaxed driving anyway, this effect is harmless... ...until you suddenly want to accelerate. Let's say that you are loafing along, engine spinning 1500 rpm or so. You instantly floor the throttle. The exhaust gas flows through the turbo and cause it to spool (spin up to speed and create boost). However, at this engine speed there isn't very much exhaust gas coming out. Worse still, the turbo needs to really get spinning to create a lot of boost. (Some turbos will spin at 150,000 rpm and beyond!) So you, the driver, need to wait for engine revs to raise and create enough exhaust gas flow to spool the turbo. This wait time--the period between hitting the throttle at low engine speed and the creation of appreciable boost--is properly called boost response. Many people incorrectly call it lag, which is really something different. Lag actually refers to how long it takes to spool the turbo when you're already at a sufficient engine speed to create boost. For example, let's say your engine can make 12 psi at 4000 RPM. You're cruising along at a steady road speed, engine spinning 4000 RPM, and now you floor it. How long it takes to achieve your usual 12 psi is your turbo's lag time. Between the two, slow boost response usually causes the most complaints. There are two aspects to consider when dealing with boost response: engine factors and driver factors. As far as engine factors go, there are many things which affect turbo lag... although most are directly related to the design of the turbo itself. Turbos can be designed to minimize lag but this usually comes at the expense of top-end flow. In other words, you can barter for instant boost response by giving up gobs of horsepower in the upper third of your RPM range. (Behold the catch-22 in designing one turbo for all uses.) Driver factors are another matter. You basically need to understand how a turbo works and modify your driving style accordingly. To sum it up, don't get caught with your pants down! If you feel that there may soon be a sudden need for serious thrust, downshift until your engine speed is at least 3000 RPM. This way there will be noticable boost almost as soon as you hit WOT. If you are going up a hill at WOT around, say 1800 RPM and your speed is dropping, you'll need to downshift just like any other car in the same situation. Remember: turbos need exhaust gas in order to spin. Let them have some when they need it.
Too long ago to remember any of that. Sorry From memory. I found a swept area formula on the web that allowed me to calculate the air density and volume. I then cross checked it with a few similar engines with similar specs and found it was almost spot on. All engines given the same volume display the same exhaust gas volume figures so it is more or less constant. ie: a 1.5 litre old design engine will have the same exhaust volume at a given revs as any other 1.5 litre engine regardless of AFR or any other variable. This makes is pretty easy to calculate gas flow. Air volume in = gas volume out. AFR doesnt matter as in theory all fuel is burnt. One last thing, remember that the turbo graphs are in lbs/per minute of air. The Cubic foot /min lines are only correct at one air temperature as the density of the air changes with temp. Your gas flow figures may have ben calculated at a different temp than mine. I picked a probable likely air temp to calculate from. Have fun figuring it out dude. It took me a while to get all this straight in my head. But once there it all made sense.
