Rallycross 0 Posted September 7, 2011 Report Share Posted September 7, 2011 Hi Guys , Some of you may remember me from the transmission section , well Im considering re building my VR6 rallycross car and was thinking about turbo charging the engune like proper job , crank , pistons , rods , full head work , the lot . But I am concerned about the levels of traction VRT's have , as with rallycross traction is everything . Can someone please give me some info on this ? Link to post Share on other sites
Daverse 175 Posted September 7, 2011 Report Share Posted September 7, 2011 well if you sort it out with 4wd and a decent controller, it should be ok, with its short back end I would imagine it would be pretty nippy across dirt. you know you cant take a vr6 proper rallying though right? Link to post Share on other sites
J5KE F 0 Posted September 7, 2011 Report Share Posted September 7, 2011 Lsd's are favoured by some, i have used before but dont rate them.. Best bet is to work on smoothing out power delivery..Just cos u have a turbo, doesnt mean u have to have a heavy right foot when launching Link to post Share on other sites
Rallycross 0 Posted September 7, 2011 Author Report Share Posted September 7, 2011 Because of rules I cnt make it 4wd it has to remain fwd or convert to rwd which is alot of work , see I have already raced the VR6 in rallycross , it works extremly well off the line with its torque but then looses out big time , so I need more power to keep up . I have a Qauife lsd fitted in the car already , and as for take offs I will master that , Im just conerned about the traction under harsh acceleration and when it comes on boost ? Link to post Share on other sites
Daverse 175 Posted September 7, 2011 Report Share Posted September 7, 2011 Ah well then youll know the regs better then me then, but i thought it had to be a specific litre? i thought it was 2 litres only or something. As vr stig says, if you turbo it youll get great power, but it will just be a power spike, you need to smooth out the power band. Link to post Share on other sites
legvw 0 Posted September 7, 2011 Report Share Posted September 7, 2011 You could run a low boost setup, or a supercharger? That way you'll get progressive boost and torque. Link to post Share on other sites
J5KE F 0 Posted September 7, 2011 Report Share Posted September 7, 2011 Sounds like a progressive boost setup is a must! Fi gives the vr sooo much more!What are the regs on tyres?? Link to post Share on other sites
Rallycross 0 Posted September 8, 2011 Author Report Share Posted September 8, 2011 Yes the top 4wd class the cars can only be 2 litre turbo , but my class is the super modifieds and its unlimited in what I can do and run . As for tyres again its unlimited any size or width , I use Avon full slicks in their softest compound , How well do the drives and gearbox hold up with say 400bhp ? Link to post Share on other sites
Rallycross 0 Posted September 8, 2011 Author Report Share Posted September 8, 2011 Right guys heres my spec list so far , see what yas think .Gt45 turbo45mm externel wastegate turbo cast manifoldfull 3.5 inch side exit exhaustforged rods and pistons lower comp ratio 9.1 ?full acl bearings arp bolts all round 262 cams ?shrick valves ported and polished headupgraded oil pumplarger injectors with custom fuel railfuel pressure regulatercustom gas flowed short inlet manifoldcustom 70mm polished trottle body70mm intercooler pipinglarge intercoolerrad relocated to the bootoil cooler with relocated oil filterboost controller omex 710 ecutwin plate clutch lightweight flywheelsqs sequential shifter16x9 Avon slicks please let me know what yas think of this set up . Link to post Share on other sites
legvw 0 Posted September 8, 2011 Report Share Posted September 8, 2011 Gt45!!!! Blimey! Link to post Share on other sites
FishWick 21 Posted September 8, 2011 Report Share Posted September 8, 2011 If the course has lots of tight turns and short straights, you might want to consider the GT35 turbo instead. Full boost by ~3500rpm or 4000rpm with a 1.06 back housing, although with your 3.5" stumpy little exhaust, those rpms might reduce a bit. I don't think a 45 will do much below 5K even with that exhaust, which might hamper your progress a bit.The 70mm throttle is a bit too big imo. Big throttles are a pain in the arse to map for smooth low rpm progression. Just look at the R32 with it's ridiculous 73mm throttle!! I've seen 6L V8s with smaller throttles! The stock throttle is fine for well over 500hp and has the nice ramp in it for progression.Don't need an upgraded oil pump but fitting the R32 (MK5) sump and pump might be a good idea for surge protection. Link to post Share on other sites
rodney 17 Posted September 8, 2011 Report Share Posted September 8, 2011 mmmm I would only add the smaller turbo may give you better ramp rather than spike on the boost and the other thing is less lumpy cams may well aid that as well.. 248 is always mentioned as something that works well with FI as it is a little less irratic...All that said..... What can the controller do to aid this?????? dual stage maps or the likes??? Link to post Share on other sites
Rallycross 0 Posted September 8, 2011 Author Report Share Posted September 8, 2011 Alryt so a gt35 r den which I have off the Subaru , as for the 70mm trottle we 3 Subarus which all run 500bhp + 1 has 600bhp and day all use 70mm , and all start to boost around 3000 , 3500 so I dont see a problem . We have found that the power is less eratic with a boost controller fitted . Link to post Share on other sites
rodney 17 Posted September 8, 2011 Report Share Posted September 8, 2011 I know what you're saying but remember the way the scooby gets its air is very different to the VR lump... no egg sucking meant ... but the way the pulse of air reach is very different from their feed to the "more traditional" route the VR6 has... I suppose this is the way forwards... Let's experiment and break/streatch the rules... don't forget a chat with people like stealth and Phirm aswell as the chaps who have bigger numbers on here.. is/are always worth while as I think they have created most things by now...This is going to be really intresting... post away my friend... Link to post Share on other sites
Rallycross 0 Posted September 8, 2011 Author Report Share Posted September 8, 2011 Yes I get where your coming from RCF , its all about finding the best set up really , as it stands I m going to build the car for Rallycross and push it as far as I can fwd and then I will consider converting it to 4WD and doing other events or going RWD . I have the funds and equipment to do it just need the rught info . Another option Im working on is building a space framed mk4 shell with a vr6 turbo mounted longitudly in the rear on a sequential gearbox what would ya's think of that ? Link to post Share on other sites
FishWick 21 Posted September 9, 2011 Report Share Posted September 9, 2011 Alryt so a gt35 r den which I have off the Subaru ' date=' as for the 70mm trottle we 3 Subarus which all run 500bhp + 1 has 600bhp and day all use 70mm , and all start to boost around 3000 , 3500 so I dont see a problem .[/quote']What does that have to do with VR6s? I've already said the stock 63mm throttle is plenty for over 500hp, but if you want to use stuff off Subarus, go ahead. Link to post Share on other sites
rodney 17 Posted September 9, 2011 Report Share Posted September 9, 2011 Yes I get where your coming from RCF ' date=' its all about finding the best set up really , as it stands I m going to build the car for Rallycross and push it as far as I can fwd and then I will consider converting it to 4WD and doing other events or going RWD . I have the funds and equipment to do it just need the rught info . Another option Im working on is building a space framed mk4 shell with a vr6 turbo mounted longitudly in the rear on a sequential gearbox what would ya's think of that ?[/quote']pop on you tube there is an example of the rwd front engine on there somewhere... I'll try and find it as well...As a point of discussion... what is the issue of going to large... lets say 70mm? Link to post Share on other sites
rodney 17 Posted September 9, 2011 Report Share Posted September 9, 2011 not the one I was after... but... Link to post Share on other sites
Rallycross 0 Posted September 9, 2011 Author Report Share Posted September 9, 2011 Im just merly making a point , I have no intention of running a subaru trottle on it , I have a custom one made . I just tought it would be beneficial for the engine to breathe more to run a large turbo .And RCF that is one serious corrado I must say 466rwhp on standard block ? I like the idea off this only in a golf , my main goal is to show people here in ireland just how good the vr6 is . Link to post Share on other sites
Recommended Posts