PRV V6 Project (Need Help!)

by **darrenbiggs** » Thu Mar 02, 2006 11:58 am

You have to watch for too much increase in overlap on the cams too.

Because it's forced induction, and by virtue of the low overlap, you can't (and don't need to) scavenge the cylinders in the same way - too much overlap on wild cams and all the boost will be blown out the exhaust valve in the mid-range. Yes top end will increase but your mid-range will suffer because you're wasting energy and the v6 doesn't rev that high to compensate anyway.

As David pointed out in another thread it would be a shame to make a 350 hp, flame spitting monster if you lost all the driveability.

by **peterg** » Thu Mar 02, 2006 2:19 pm

As David pointed out in another thread it would be a shame to make a 350 hp, flame spitting monster if you lost all the driveability.

No it wouldnt!!! Well, not as long as it had loads of torque to go with it

by **stephendell** » Thu Mar 02, 2006 8:18 pm

Oh yeah, so its hard enough to find a car with the prv v6 in it, let alone trying to find a 24v version!!!!

I've got a couple of 24V engines going spare :wink:

Is there anyway someone can send me DOHC heads, intake manifold setup and ill pay shipping (and cost)?

Don't think anyone makes a DOHC head for the PRV. If you really want that then best to just buy a Clio V6 engine and fabricate mounts. 24V and DOHC as standard.

by **Tony Smith** » Fri Mar 03, 2006 2:57 pm

If I'm not mistaken the most powerful PRV based production car will be the twin turbo 400 bhp plus engine from the Venturi - rated at 395 bhp and 383 ft/lbs in standard form they were reputedly good for 650bhp in race trim. I've been in a road one with some extra boost and it was a serious animal! I think the cams are the key on this version as the turbo installation (pair T25's with a pair of smallish intercoolers) looks straightforward enough.

by **David Gentleman** » Fri Mar 03, 2006 11:33 pm

The 650 bhp 24v versions ran twin T3/T4 turbos, 1.4 bar of boost on standalone management, and a Hewland box, as the standard UN1 can only handle about 350bhp..

by **gt5** » Sat Mar 04, 2006 9:47 am

so 350ish bhp is our limit unless we uprate our boxes which will cost 1000,s

by **David Gentleman** » Sat Mar 04, 2006 1:29 pm

gt5 wrote:so 350ish bhp is our limit unless we uprate our boxes which will cost 1000,s

Yes, £1750 for a primary shaft upgrade to stop it shearing (common over 350bhp) and an uprated clutch to go with it (circa £300-400)

Option of either an A610 or modified Lotus S4 unit

by **clee** » Sat Mar 04, 2006 1:39 pm

http://www.un1.co.uk/Upgrading%20the%20UN1.htm

by **peterg** » Sat Mar 04, 2006 4:43 pm

gt5 wrote:so 350ish bhp is our limit unless we uprate our boxes which will cost 1000,s

I dont think this is going to be a concern if you are retaining the PRV engine somehow!!

by **gt5** » Sat Mar 04, 2006 5:27 pm

why?are you saying its not possible to achieve that sort of power without pulling the bottom end apart

by **peterg** » Sat Mar 04, 2006 6:04 pm

Its not possible to acheive it without going for twin turbos which will involve a complete re-jig and cost lots of money! If you are worried about the cost of the gearbox upgrade then you cant afford to get to the stage where you'll need it!!!!

by **gt5** » Sat Mar 04, 2006 6:16 pm

the thing is nobody knows if it is possible to achieve that sort of power with the single turbo,as i asked in another post has anybody took the standard setup to its limits(no boreing/strokeing twin turbos etc) :?:

by **peterg** » Sat Mar 04, 2006 6:24 pm

The factory acheived 287bhp with cams as well as all the kit we have. Their conclusions were that with the set up it wasnt possible to go far beyond that due to the restrictions in the single turbo set up. We have been round and round and round the power topic for as long as I can remember and I know you have been party to some of the debates!!! Venturi the other manufacturer who used the PRV for serious performance went the twin turbo route to acheive power......dumping the standard single turbo set up is the only way you are going to go significantly beyond 300bhp. Everyone knows this.

by **clee** » Sat Mar 04, 2006 6:28 pm

Std exhaust manifolds I think

We have been over and over this subject but then until recently it was thought piggybacking wasn't worth the hassle :mrgreen:

It would seem to be a worthwhile mod and from what I've read from various sources pretty straightforward .

by **peterg** » Sat Mar 04, 2006 6:35 pm

We've done that topic too.......putting decent manifolds on wont help very much because they meet at the turbo so there will still be a restriction in the system. Its not possible to move the turbo anywhere else easily due to the V nature of the engine.......can you think of any other manufacturer who has produced a single turbo V engined car??? I wonder why!?? :lol: