Where did you get that from Ali I think the Z1 reference was to a different turbo but could be wrong send me the link and I will look into it Mattz all cars have back pressure of some form especially zeds. What I was mainly getting at is more related to setup. For arguments sake you run a GT2871RS turbo with a .86 rear housing, Typically the housing and wheel size dictates you require more air flow/greater velocity to spool the turbos. So if you had a mild engine and wanted to run the turbos a 2.5 inch siamese dump pump and full 2.5 inch dual exhaust with crossover pipes would be better. This setup would build backpressure and help keep the exhaust gases flowing at a higher velocity at lower RPM so more streetable. For a race car however and a built engine you would go a 3 inch open mouth with divider strip and full bore 3 inch low back pressure exhaust as the engine would sustain the required air flow to spool the turbos etc. The whole idea of turbocharging is to achieve greater air flow into an engine so it makes more power. The US guys want to run a turbocharger at its maximum efficiency and highest boost pressure, they generally do this due to mostly cooler ambient temps and they want boost response through the whole rev range. Out here its a little different bigger is better. Running a larger turbo at lower boost making the same power as a smaller turbo will generate less heat and put less strain on the engine and related components as a whole but its a fine line turbo selection is key and we are doing the utmost to come up with suitable solutions and using my stock engine as a test bed initially. I am working on the figures tonight and plotting the VG30DETT in stock form on various turbo charts to see where we are at in terms of options. The last thing I want to see people do is fork out a heap of money on a small turbo and find it doesnt make the power they want it to or the reverse and buy one too big that requires a heap of engine work to run. Lastly remember the mighty 2JZ they put T88 turbos on those things for a 3l capacity engine and even in stock form can pump out over 600rwhp a built engine can see upwards of 900rwhp you wouldnt think its possible looking at the compressor maps but it works so dont discount the VG just yet it may hold some untapped suprises.
Did you even read my post or any of the other posts in this thread for that matter???????????????? Z1 kit spools quickly because it is the .64AR version of the GT28RS. THIS IS NOT A SPECIAL TURBO FROM Z1. This same turbo can be supplied by GCG in australia for the SAME RESULTS.
Ali stop street racing and come to the track mate you will be hooked too for sure Lag is a misconcieved idea with many differing opinions on 1 what it actually is and 2 how to minimise it. The easiest way to explain Lag is - the amount of time it takes a running engine under full power or load to spool a turbocharger to produce the desired boost pressure. Okay thats sorted now onto what creates lag. Yes it is true that a larger exhaust housing bigger turbine wheels etc will all generally increas turbo lag generally being the key word. Turbo lag itself is usually very minimal system lag is another topic altogether. People often claim that after a fmic fitment there car seems laggier they are correct, they have increased the actual run length or the cubic volume of the intake tract that the turbocharger must fill before producing actual boost. I mentioned before about exhaust sizes etc. You can run the same GT2871 or 60RS turbo both with .86 rear housings etc on a 2.5 inch dump and exhaust system with crossover pipe and proper mufflers, then you can change over the components to a full 3 inch dump 3 inch full minimal backpressure exhaust and the turbo will be laggier, Why, because the exhaust velocity driving the turbine wheel has been reduced due to the lower packpressure. The same goes for intake pipes etc the less physical restriction you have in the whole intake tract the less laggy the turbo will be, same goes for heads, plenums manifolds everything but doesnt necessarily mean you need to go out and spend a heap of dosh going nuts on a fully built engine. You just have to understand what to expect from the setup. Ultimately how much power would you like to produce both now and in the future i.e planning on rebuilding the engine any time soon etc I should also add if planning on putting the GT 28RS turbo on the stock engine it will be laggier than stock without mods to exhaust etc similar to whats mentioned above Spot on Rob except the Z1 Kit comes ready to bolt onto the VG30DETT the standard GT28RS does not. The kits are supplied with adaptor flanges for the stock intake pipe to bolt to and line kit etc, however this is how the kits will be supplied by GCG, zed specific bolt on full kits with quality fittings and specific custom 5 bolt dump pipes in either 2.5 or 3 inch oh yeah new development being worked on
Yeah i know what your saying Jason But again its all about the application of the turbos. You want for track racing lol but i want for street use haha I dont want to floor it and wait...wait...wait....and booooooooom their it goes- Its good for the track because once you build boost then your always gonna have it aslong as you keep it high up in the rev range. But for the street it aint good. Bottom line...is their going to be a kit that uses a disco potato with a 0.64AR like the Z1 kit...? Here is the link to the comments i posted earlier Jase The GT2871RS Z1 Kit with 0.64AR for quicker response.
hmmmmm soo many choices makes it kinda hard. for a streetable car im thinking the GT600R (28R) kit as from what I understand it would be a bit nicer on the street than the GT675RS (28RS). So I guess is it possible to make the RS as responsive? I'd like to only have to buy turbo's once... but then again I want a car that is responsive to enjoy on the road and good for say 500rwhp so that I can brag
I understand where Ali is coming from, and I've said the same thing in a previous post. Lag is an issue on the street hence the reason why tubro manufactures have developed variable vane technology and are researching electrically assisted turbos. In fact there has been a hand full of previous cars that were manufactured to include both a turbo and supercharger to eliminate the effects of lag.
Yes Ali there will be see earlier post mate. However if you are planning on putting the GT2860RS (the link you supplied is for this kit not the 2871RS thats the new GT725R kit) kit on your stock engine it will be very laggy over the stock setup at a guess I would say it will start boosting at around 3300 rpm and hit full boost at maybe 4400 - 5000 or so you really need a mild engine or a really good exhaust intake setup to use these turbos and that was my point for like an extra $200 you can get the GT2871RS kit which will support all future mods and builds etc. If its fully tear away from lights boost on tap you are after go the smaller GT2560R kit it will be much more responsive on a stock engine and still provide close to 550 hp with supporting mods. How much power due you want to make Ali? and do you want the turbo uprgrade for the standard engine, mild engine or built engine??? Spot on Claymen you get is mate it is a comprimise, thats why I mentioned the possibilities above for those like me who would like a bigger turbo for future builds but may be putting it on a stock or mild build engine for now. After all there will only be a couple of hundred dollars in it between the cost of the 28RS kit and the 2871RS kit (GT675R and GT725R kits Z1 naming) Its tricky thats for sure
Hopefully as early as 2 weeks. I believe the fittings are all sorted and the adaptors are being machined and trial fitted with stock intake pipes. We are looking at also doing a custom 2.5 and 3 inch dump pipe to suit the turbos aswell and this is currently underway. Rough price idea for the GT28RS kit with .64 rear housings with all motorsport quality Earls fittings and material braid hose, gaskets etc etc as per normal kit plus either 2.5 or 3 inch dumps will come in at around the 4.5 to 4.8k mark Seems high at first glance but convert 3k USD and add about 400US for shipping plus another 500 USD at least for good dump pipes and it adds up pretty quick. I can find out more tomorrow and let you know, how quick were you after something and also what turbos were you keen on BHP Jas
interesting so as im doing a rebuild with a reasonable amount of work on the engine (forgies, ported manifolds and some headwork etc) would you suggest the GT600R or GT675RS (eg GT28R vs GT28RS)? I mean is the RS going to end up more laggy than the R or are they pretty close and with reasonable work and cams they should be pretty close.
that sounds quite reasonable, i have been looking at the hks gt2530's so i want the ones that are pretty much the same specs as them, the 2530's are 4.5K or similar just to buy, without shipping costs, dumps, etc, i will be looking at about two months possibly sooner, have a huge expense on bodykit and paint very soon cheers
Check the charts they are very very close I would probably go the GT28RS it flows slightly more for any given pressure ratio compared to the 2560R ones T25 and ones T28 frame so overall not much difference the wheels are slighlty larger and feature different trim in the 28RS. For a mild motor the 28RS would be the pick and be good for 600hp with supporting mods. You will need 740cc injectors though the 555's wont cut it me thinks
Z1 GT675RS Turbo kit Actually, we have improved on our turbos again. We have changed the brackets, and a sortment of other parts. Z1 will always try to improve on product. If we see that a part is in need of a follow up, we will address it. All of our turbos have a 12 month Garrett warranty, but this is only a production warranty. Oil contamination, and debris flying into the wheels void it of course. Lag is really not an issue with the 675. keep them at 18psi on pump gas and you have a very nice sweet spot. Add in a set of 4:10 leader gears and you have a car that is outstanding. The 725 is a laggy kit, but it is still streetable. I would suggest a NOS spool up kit for that.
Dump and engine pipe pics These were made for Shifters car. Tig welded one off custom jobs made from stainless and 3 inch. They are probably the best dump and engine pipes ever made on a 300ZXTT. Made at UAS by a Motorsport engineer over many days so one off is very expensive but production run very cheap. They are complex and highest flow whilst keeping it tight under the car to clear the large 3 inch pipe work tight under the car runnning around the starter on drivers side. We are planning to use these as a jig and get made in mild steel and mass produced with longer sections of mandrel bends. Big mouth design straight off the back of the turbo and may put a divider inside like Nismo and HKS do on some of their dump pipes. These non turbulence ones are over rated we have found on tests on Skylines at least and believe zeds will be same or worse due to space restraints. The problem with zeds is that there is not much room as close to firewall and drivers side has steering shaft to dodge on top of that. The total surface area of the mouth of non turbulence is probably about 80% of a simple one opening type. Plus the non turbulence ones do not have very big pipe for the critical first 6 inches or so and then flare up to 2.5 or 3inch mainly due to the space limitations. These bling plished staino Chinese ones that some are getting excited about flow stuff all more power than stock cast iron ones, mainly as they are only 2 1/4 inch and smaller than that coming off the back of the turbo. Once on the car you don't see them but look good pictured on websites. Most on the market are mass produced and not big enough pipe especially for the larger one exiting the bulk of the heat and gasses.
already got 650cc sards the RS is looking attractive thats for sure... so by what your saying its flowing more at any given pressure level which in turn means more power at lower psi compared to the straight 28R? but what about the effect it will have on lag (as much as I hate asking it). i mean you dont just get free extra power without something being compromised on.
I am not 100% sure of the exact difference but it will be there. The Compressor wheel is larger but the turbine wheel is the same size so it will be slightly laggier i.e time taken to pressurise the increased cubic volume of the intake tract etc but how much I am not sure I am working on plotting the stock VG30DETT on various compressor maps over the next few days and will see where the stock engine sits in relation to different turbos. That will give the baseline to go off according to engine mods undertaken etc and a fairly accurate result can be obtained with this info and some slight educated guessing. Stay Tuned
Hi John Thanks for the info again The one main problem I see with the kit is not the kit itself its the freight cost. I think you guys use fedex which is very expensive to ship anything to us here as a one off. When I enquired about Russells TD06 kit freight was going to be 450USD from memory. The aussie dollar is doing well at the moment but not that well I understand they are heavy etc but can we maybe look at some alternate shipping methods for the Aussie market such as USPS express air mail service etc. I think if the freight component could be minimised at least for smaller orders such as hard pipe kits, injectors and other smaller items a lot more business would come Z1's way. Just a thought Jas
