Ok, I've had a couple of years off any serious f*cking around with Volkswagens, and at the moment I'm feeling inspired! I always wanted to stick a blower on the AAA motor in my '85 mk2 but despite having most the bits to do it a while back, it never quite got there and I was skint so sold it all. However, I'm considering doing it all again... because I'm quite mad!! So, I'm after recommendations really... The idea I have at the moment is to aim for a moderate 350bhp using mostly stock internals to start with then build it up from there. Here's the list of bits I have at the moment: Stage 1 Turbo - Either a Holset HX35/40 or if I can afford it a Garrett GT35R. Has anyone had any experience with the Holsets?? Wastegate - Tial 38mm with screamer pipe Manifold - Cast, externally wastegated Downpipe - No idea who produces these? Perhaps United Motorsport or someone similar, prices?? Oil feed kit - Pretty self explanatory... will probably run a "tee" piece off the oil filter housing, then braided lines Uprated clutch - Really not sure who to use here, but I'd rather up the spec of the clutch if poss Injectors - Bosch 440cc's(green's) with a 4bar FPR(probably an adjustable one actually) Head spacer - Exactly what it says on the tin.. these are Uber cheap these days!! Head studs - ARP, unless anyone has experience of using others Rod bolts - Again, as above Short runner - Definitely NOT schimmel!! DG Autotech used to do these based on the lower manifold, and use some nice shiny fittings too, with a billett fuel rail, so trying to find out if they still do(or at least Dave Dewson). Anyone recommend alt Pipework - Will need to get these fabbed, use Forge silicone jointers(as they knock the VAT off if you visit them in Glozzer ) BOV - Forge again most probably, atmospheric naturally Intercooler - I'd like some recommendations on IC/Fan setups if anyone has any for the MK2. Bear in mind I'll be using a short runner so won't have a huge amount of space to play with ECU(MSNS) - Considering going down the megasquirt route here as I mind electronics fun(sad)... Although I may see if I can find the cash to splash on something that has launch control/antilag capability for future expansion Wideband lambda - Probably just use an Innovate LC-1 as they seem to be the standard for wideband Various other bits and bobs I'll need to think about including modding the sump for the oil drain, but myself and a mate can knock that up! Anything obvious and/or expensive I'd forgotten about?
Some inlet mani options: http://www.ebay.de/itm/VR6-Turbo-An..._Autoteile&hash=item3a5f676dfd#ht_2505wt_1277 http://www.ebay.de/itm/VR6-Turbo-Sp..._Autoteile&hash=item3a629fdc62#ht_3134wt_1214 Would you really need to spend a few hundred on the ARP stuff, you'll be running very low boost for that power? Clutches, prob Helix or Sachs or C&R do some Black Diamond on the bay at a half decent price. Have you thought about a diff too, pretty much a must for a turbo fwd car. EDIT: If you use an SPA cast exhaust mani you can run regular inlet manifold path/intercooler
Some nice manifold options there, cheers. I have thought about a diff yes, and I think if I can claw back some of the cost from the turbo it'd definitely we worthwhile doing. The problem I have is that if I go for the GT30, I'll have to cut back elsewhere.... but then it's a ball bearing turbo so will spool easierand the power will be delivered slightly more progressively, but it's an extra 700 or so ) Tough choices. As regards the bolts, I'd prefer to use them for piece of mind really. As they aren't very expensive, it'd be stupid not to use them, as I could re-use them if the bottom end went bang.
Nah, a GT30 won't be that much more, a T3 60-1 is about 650 and the 30 you should get for a grand or so, so more like 400 more. Ever thought about a PT6262 or seeing as you're going lower boost a 5858 journal bearing or the like, they go for about 800 or so and nice CEA comp for the price (make sure you specify new stock though). I did have an e-mail from a supplier this morning in China who's just started making forged parts for the VR's and as i'm doing a few 24vt kits i'm keen to test them out due to their price. Just waiting on some more details about the specs/engineering side of things and quicker delivery etc then thinking of putting a group buy feeler up. Think i'll be getting them anyway just to test their durability in the engines. With economy delivery and a small profit I'd be looking at around 250 a set if I buy ten or so, pretty much the same as some ARP hardware! That's also including the 20%vat and import duty i'll get hit with.
PS I'm open to suggestion on the turbo choice... I just don;t want to break the bank, and not do I want to be wringing the life out of the turbo higher up the rev range meaning it leaning off
Will put a feeler up when I get some more detailed info and final costings on the rods methinks, worth a try at that price really, I can always build another engine and won't really know the in's and out's till they're in my hands. The 0.63ar on a T3 will and has been seen to flow well past 7000rpm's with no backpressure problems, many prefer 0.82 though and it's a bit easier on the box (Frozen Solid can help you here). Some even swear by a T4 on the VR's! It also comes down to the spec of your set-up. Gasket matching, big valves, porting/polishing, cast or tubular manifold, shape of exhaust mani and collection of gases, ID of runners, shape and size of downpipe etc etc - these all contribute to back-pressure/turbulence/flow problems and alleviations, not just the turbo..... I assume that's what you were on about in terms of gas dynamics? You can plot the comp's efficiency pretty easily. Can do one for your 12V at various VE's if you like when i've time. Copied this for you as an idea although I am redoing them as it was a good while ago and not sure i've put the correct info up, think I may have used 14.5psi instead of 14.7 as I was doing fuel calcs too at time or it may have just been the psi to bar I did that? They are a good rough guide though: 2.8 24V AT 93% VE 40 LBS/MIN = 10 psi/ 0.68 bar of boost 45 LBS/MIN = 13 psi/ 0.88 bar 50 LBS/MIN = 16.1 psi/ 1.1 bar 55 LBS/MIN = 19.2 psi/ 1.3 bar 60 LBS/MIN = 22.3 psi/ 1.51 bar 65 LBS/MIN = 25.4 psi/ 1.72 bar 70 LBS/MIN = 28.5 psi/ 1.93 bar 75 LBS/MIN = 31.6 psi/ 2.15 bar 80 LBS/MIN = 34.6 psi/ 2.35 bar 85 LBS/MIN = 37.7 psi/ 2.56 bar 90 LBS/MIN = 40.8 psi/ 2.77 bar 95 LBS/MIN = 43.9 psi/ 2.98 bar 100 LBS/MIN = 46.9 psi/ 3.19 bar 2.8 24v AT 100% VE: 40 LBS/MIN = 8 psi/ 0.55 bar of boost 45 LBS/MIN = 11 psi/ 0.75 bar 50 LBS/MIN = 14 psi/ 0.95 bar 55 LBS/MIN = 16.8 psi/ 1.15 bar 60 LBS/MIN = 19.6 psi/ 1.3 bar 65 LBS/MIN = 22.5 psi/ 1.5 bar 70 LBS/MIN = 25 psi/ 1.7 bar 75 LBS/MIN = 28 psi/ 1.9 bar 80 LBS/MIN = 31 psi/ 2.1 bar 85 LBS/MIN = 33.8 psi/ 2.3 bar 90 LBS/MIN = 36.9 psi/ 2.5 bar 95 LBS/MIN = 39.8 psi/ 2.7 bar 100 LBS/MIN = 42.5 psi/ 2.9 bar Can't remember what I did these for as it was donkey's ago, again rough VR guide, think it was 24v 98%VE/3500&7000rpm plots/100 deg F inlet temp - will check when i've time Flow rate per boost pressure plotted on 42X: Also twin turbo GT25's
GT35R is perfect. 0.82 back housing will seen full boost (15psi) by 3500rpm and holds torque flat to 6500ish with a decent short runner, 263 cams and map. 1.06 back housing will see full boost by 4000rpm and holds torque flat to 6800ish...... 268-272 cams will extend the torque out a little more. GT30 will be out of puff by 5.8-6k with a .82 This is based on me actually using these turbos on my engine. T60-1 is very similar to the 35R but cheaper. Don't read too much into ball bearing turbos. They don't make much odds with 2.8 litres of exhaust spinning the turbine wheel, but they do help (along with other optimised parts) if you want the least lag possible.
Thanks guys this stuff is really helpful. I guess you're right about the back pressure from the 2.8, and I can see why using ball bearings on a 4-banger is more important.... Looks like the t-60-1 might be a good bet. Any suggestions for suppliers?
Not sure how trusted they are, but: http://shop.streetracersgd.co.uk/index.php?p=product&id=78&parent=38 Well used authorised dealer: http://www.owendevelopments.co.uk/ Something a bit different: GT35R Similar http://www.ebay.co.uk/itm/Precision...arParts_SM&hash=item1c20eab9cb#ht_1708wt_1133 Bit like T3 60-1 http://www.ebay.co.uk/itm/Precision...arts_Vehicles_CarParts_SM&hash=item1c20e7e863 My fave if you're feeling flush: http://www.ebay.co.uk/itm/Forced-Pe...arParts_SM&hash=item1c20f4aef1#ht_1497wt_1133
