VR6 BHP limits and c2 software

[Craig 0]

Hello all,

 

Ive trawled through the net and on here and would like to just get all the info in one place and ask a few questions to make sure its correct.

 

Ive got a rotrex c30-84 charger on my Vr as in my build thread and have been trying to weigh up the costs of carrying on or selling up as i was a bit naive in underestimating the costs to FI.

 

I wanted to confirm what people feel would be a suitable limit for bhp/psi on stock compression/internals?

 

what is a suitable limit for boost/bhp with no cooling?

 

How easy is it to install water/meth injection. is it even worth it?

 

If a lower compression gasket and arp head bolts were used what would this take the bhp limit up to?

 

I noticed the c2 software has been used before by a few on here and i was wondering will a late style obd1 4 pin maf fit a 4" maf housing that was designed for an obd2 maf? they appear the same fitment and design.

 

sorry for all the questions but i wanted some clairty on the routes i can take.

[Kevin Bacon 5]

All of this has been covered in the FI VR6 thread. Admittedly it's a big thread that needs careful searching, but it's all in there.

 

I would say the power / reliability compromise is 400hp. Quite a few people across the globe have had stock pistons let go at this power, including a member on here who ran a Rotrex also. Despite how beefy the VR6 block seems, the piston's ring lands don't seem to be all that strong with FI. Which is why if you want FI + 100,000+ miles potential, you need forged pistons.

 

People always claim silly amounts of power from stock internals, but ask them how often it's driven and you seldom get a straight answer. Very few people document engine failure on forums, they only boast about how much hp it's got. People who've driven FI VR6s every day for 1000s of miles paint a more accurate picture ;)

 

I personally wouldn't run boost with no cooling, period. But people do do it. No more than 8psi I would say, but be prepared for the power to reduce as heat increases.

 

Water / meth can have good results, but it's no substitute for a decent intercooler. It should really only be treated as supplementary cooling.

 

A spacer won't increase the power handling as the pistons have limits as already mentioned. But it will considerably reduce detonation.

 

Yeah a 4 pin OBD1 MAF will fit in a 4" housing but I'm not sure C2 still do OBD1 chips?

[Craig 0]

Thanks for the reply Kev, much appreciated. Ive currently read through up to page 50 on the fi thread and still going when have the time for a glance :) also making notes and saving web pages but as you say I'm also trying to ascertain what is still available as with c2. :) guess this can be locked then.

[alex303 0]

If you're looking for a Spacer gasket & some ARP's then drop me a line as i have a new un-used Schimmel spacer gasket kit (1 point drop in compression) plus a set of brand new / sealed ARP head bolts & studs that will probably be selling in the next few months.

Alex.

[poll250 0]

I'd go with the 4" MAF housing if you haven't already as it means you don't need a MAF clamp or potentiometer. I think C2/United Motorsports should be able to sort you out if you've got a later CP coded ECU (which you'll have it you have the 4 pin MAF).

 

Meth Injection is a good option, and isn't too expensive. You should also be able to find a charge cooler set up pretty cheaply I'd imagine.

 

It would be a shame to give up after coming so far.

[Craig 0]

Thanks guys, appreciate the advice. I was toying with the idea of selling up as it is and letting someone else fit the 312s and get it mapped and i was seriously considering looking at the charged 4motion on ed38 as its somethiong newer and more refined but i do love the rado shape, driving postion and the way it drives. I drove a mates standard 4motion and it felt like a bus, and the back ends are quite fat and square, dont get me wrong the low down engine response was sublime compared to a vr6 but overall it made the vr6 feel like a caterham, light and nimble.

 

I just didnt anticipate spending another £1k on a remap/injectors after spending so much on the charger etc, my fault for lack of experience and being a bit naive.

 

People are always posting about their FI exploits and now i have an understanding of how much they must have spent!!

 

Think i will look into a 4" maf, cant seem to find any 4" filters though to fit on the end? and i was hoping my 4 pin maf would fit.

 

not sure on costs for a charge cooler, only issue would be then having to use a short runner intake? and ive no idea about a meth set up, something else to research :)

[Fanjita 1]

Just put a 24v into a Rado then?