48 replies to this topic

[Vespa]

Hi guys I've been offered a GT28RS at a good price but just want to know if any of you actually have one and what it feels like to drive/ power gains etc... What else besides the turbo itself would I need? I'm assuming a charge cooler but what else?? Any feedback regarding this turbo installation would be greatly appreciated! Cheers Alex

[theolodian]

It's pretty small for 2L, and tiny for 2.2 (You did not specify your engine). You will also need a manifold, downturn, lots of fabbed parts, remap, etc. Even if you get the turbo for free then you are going to spend about £2K maybe more getting it installed depending on how you go about it.

[danger7]

Hi all, I have a GT2871RS fitted, the work was done by a german tuning company and the main mods were to take the original Z20LET manifold and fabricate the mounting flange, a pop off valve system was installed, the AMM was disconnected (lambda & inlet temp are primary inputs for the ecu now). I ran for a few months without charge or water injection and i had no problems with temps (albiet careful not to run at full boost or prolonged acceleration). The cost for conversion was Euro 1,500 if i remember correctly which included the all important remap. Overall with 360 bhp the car pulls as you'd expect, there is more lag with max boost now at 3800 rpm it spools up slower the the kkk or aet turboladers but once up to 1.5 bar its acceleration is brisk I've done 8000 miles on the conversion and I have had no problems with the turbo. The downside is if you have a Z20LET engine then you'll be restricted to 300 bhp as over this its a life shortening engine experience. Cheers Ian

[Vespa]

Thanks for the reply ian! So would I be correct in thinking that if I had the GT28RS It will be laggy until 3800rpm? But will pull until 6300rpm? At the moment I like how the original kkk pulls from so early in the rev range but am dissappointed at how early it runs out of boost. I would be more than happy with limiting it to 300bhp as you are right in thinking that I do not wish to do any internal mods to the engine. Is there anyway to get it to spool up quicker? Apparently it has the smaller turbine housing (0.6) would this make any difference? I see regal autosport do Dibilas manifolds, is this the manufacturer you're using? Also do you have a power graph so I can compare with my setup? Thanks again!

[Steppenwolf1980]

I have a mate running a bigger Garrett-Charger in his Z20LET, producing a little over 400hp. As with every bigger charger, the lag between pressing the throttle and reaching the right boost is a lot bigger than with a genuine LET-charger. Below 5000RPM nothing happens in the car, the charger just doesn't start then. But from 5000 on until 7800 (yes, this is is maximum rev!) it feels like sitting in a jet fighter. You've got to be VERY quick with shifting. The car does the 0-160mph sprint in 10 seconds. BUT: Almost anything else in this car has been also modified, starting with the cranks, pistons, pistoncooling, 100mm exhaust system, new air intake system, clutch and so on. The whole conversion cost about 9000 pounds. Usually you'll have to rebuild your engine with stronger parts when going over 300 to 320hp. Of course it's a absolutely weird feeling to have such a powerful car, but it depends on what kind of road you'd like to be fast at. I wouldn't convert to a Garrett, because I mostly drive mountain passes, very narrow, very winding. It would be no fun with such a dull car, so I stick to a VXR charger and 300hp, that's the perfect setup. Otherwise, if you like to run very fast on the motorway (like the Germans do) or want to use the car primarily on the track, a Garrett-Conversion makes sense. The faster and longer the race track is, the better you'll see the benefits of the powerful car.

[Vespa]

Do you know what garrett turbo your friend is running? It sounds lime it's probably the GT30 if he's in lag territory until 5000rpm. I was told the GT28RS wasn't actually that big as it uses the T25 housing and would therefore spool up really quickly but run out of steam quicker. I just hate the way my original turbo runs out of boost so early. Is the difference between the VXR turbo and the GT28RS?

[Vespa]

Ah sorry, I have the 2.0 turbo. I'm just not sure whether it's my turbo beig too small wheich means it doesn't pull at high revs or whether it's the superchips map. I bought the car like this so i don't know what a standard vx220 turbo feels like?

[cheeky_chops]

At the moment I like how the original kkk pulls from so early in the rev range but am dissappointed at how early it runs out of boost. I would be more than happy with limiting it to 300bhp as you are right in thinking that I do not wish to do any internal mods to the engine.

have a lookie here - should give 30bhp more top end, jon was really surprised how much it gave as its only envisaged to work for the GT range! i have a courts one on order, hoping it will go well with my piper cams!!

http://www.vx220.org...nlet-manifolds/

[Vespa]

That's the sort of drop off I'm talking about, apart from my power is nowhere near 300bhp max power is only 232bhp @4400rpm then dwindles away. Does anyone have a GT28RS setup from courteneys?

[Steppenwolf1980]

I think my friend has one of the GT35 series, but I'm not sure about that. For sure it is no GT28, because this one can't produce more than 350hp, if I'm not wrong. Well, when you currently have 230hp, why thinking about switching to a Garrett? As I wrote, my perfect setup is a VXR charger with a reasonable setup (Software, uprated clutch, oil cooling kit). If you'd like to run the car on higher RPMs, then you should either add racing cams or the new High Flow Inlet Manifold from Courtenay/Klasen Motors. The result is the same and both of them are expensive... But whatever you do, no Garrett-Charger will respond quicker than a LET or VXR charger. Another possibility would be the new "Next Generation Chargers" available at some German tuners. It's basically the housing of a LET/VXR charger (the housing is the same), but the turbine wheels and some other stuff is being changed and they are producing 320-330hp with the same quick response as the genuine charger. Of course this is the absolute limit that the engine will be able to deal with, as long as you don't change pistons/cranks/cooling.

[Vespa]

Thanks for the great answer mate! Perhaps I should just by the VXR charger then if the 28RS won't spool up as fast! Do you have a charge cooler on yours asivr heard this will really help with engine longevity? I think rapid throttle response is the most important thing forthe VX220 especially as I'm not planning to take it to the track. Just out if interest where abouts are you in the uk?

[Steppenwolf1980]

Well, you're welcome. Of course I do have a charge cooler in my car, and so do you! Without it you won't be able to run a turbocharged car properly The difference is just that I don't use the genuine charge cooler anymore, since I have Stage 3. So it was replaced by a bigger one with the four time volume. The GM charge cooler is tiny. By the way, the charge cooler isn't really meant to make the motor live longer in first place, but through the bigger volume it can cool down the air better. The cooler the air, the more power you have. Especially during hot summer days a bigger charge cooler won't let the power output decrease so quickly. On the other hand, a big charge cooler makes the lag of the charger a little bigger, but I don't really mind that. Look at my profile, I don't live in the UK...

[Nev]

dude, you can easily get to 300 BHP with the std OEM turbo.

[Vespa]

The standard vx220 doesn't come with a charge cooler as standard. It has a small intercooler which is way too small for engines with anything above 250bhp. The water cooled or charge cooler definately seems like the way forward! I've been readig up about the GT28RS and apparently it's super quick to spool up sacrificing ultimate power at high revs, that sounds perfect forthe VX220.

[Vespa]

You can get 300bhp from the standard kkk? I'm sure I've read on here it's way too small forthat? What other parts to you need?

[Steppenwolf1980]

Take that link: http://www.vx-perfor...php?cPath=47_21 I currently use Stage 3 plus some other modifications (large exhaust system, light flywheel and so on). Stage 3 with standard exhaust has 284hp and Stage 3,5 (with large exhaust system, but a different charger manifold) produces 309hp. So I'm kinda in the middle. And from Stage 3 on you use the VXR charger, not the LET.

Edited by Steppenwolf1980, 06 March 2010 - 05:41 PM.

[Zoobeef]

Its possible with the standard Astra Vxr turbo. That is what Nev is currently using and is at 300BHP. To get there obviously need CC, exhaust, clutch, flywheel, larger Amm, balencer shafts deleted, actuator, vxr injectors. Maybe a few other little things but it is possible. Duncan VXR is similar with the AET Hybrid vxr turbo and is just over 300BHP with smoother delivery.

[Steppenwolf1980]

Just saw your other post. I thought that you mean the air cooled intercooler in the right tubbyear when you talked about the charge cooler. So I suppose you mean the water cooled charge cooler from Pro Alloy? That strange thing for 1400 quid? Well, if you've got too much money, go on and buy it. In my humble oppinion it's just too expensive for the little benefit, that it brings. I use a self-built water sprinkle system for my charge cooler, which might not be as effective as the Pro Alloy one, but also brings a big benefit on hot days and cost me about 20 pounds and a little working time. So it's up to you what you'd like to build in your car. Because of the link to the German tuner, I'll list what his Stage 3,5 is including: *VXR charger with modified manifold *Airbox Kit *large charge cooler (NOT watercooled!) *additional oil cooling kit *VXR injectors *large exhaust system *new software mapping *balancer deletion kit That's all. Of course the standard clutch can't deal with that, so you're supposed to have a better one fitted. And by the way, I hope I don't have to mention to have the rest of the car already upgraded at this point (wheels, tyres, suspension, brakes).

Edited by Steppenwolf1980, 06 March 2010 - 05:50 PM.

[Bindegal]

I have done engine managment on several Honda´s on GT2860RS turbos. With the standard housings, excellent T25 flange replacement turbo, nice spooling little turbo. Usually flows to around 300hp easily, maybe 320. My guess is that you will se 7 PSI at around 2500rpm on a 2.0 . atpturbo have T3 housings for the RS which flow a little better, usually to around 340hp and a little more free flowing which helps somewhat with detonation so you can push it a little more. In the case of a VX, the T3 housing should give you a little more protection when everything is heat soaked. But it will spool up slightly later. One thing to keep in mind though - and I have seen this on a couple of cars over the years - the ball bearing turbos usually don´t last as long as the regular good ol´ sleeved bearing ones. So for a daily driver kind of car, start saving up for a new one at around 50.000km just in case. The ball bearing turbos are also very picky with the oil supply so make very very sure there´s no foreign objects of any kind in the oil line when you fire it up. Regardless, GT2860rs would probably be my choice for a driveable 2 liter engine. /Allan

[Vespa]

Thanks a lot chaps!! By the sounds of it whatever I do from here (230bhp) I'm gonna need a charge cooler or at least a higher volume intercooler. Is the balancer shaft deletion kit a necessity as I'm guessing that's an engine out job and therefore expensive? My friend has a ramp at home, is it a nightmare or relatively straight forward? It seems most of you have the hybrid VXR turbo to replace the original kkk unit, so I'm thinking if I'm gonna change mine I may aswell take my mate up on his offer for the GT28RS as it's just as cheap Well the suspension was upgraded using an adjustable Nitron kit and set up at TMS but still using standard brakes and tyres. I don't seem to be able to find any search function on this forum so am struggling to find out info you've all probably discussed at length. But how long would it take to fit a charge cooler from say pro alloy, at home? I guess it's time to raid the piggy bank! Thanks for your help everyone!!