Harveys Headers.... having your cake AND eating it ...

Hi Guys

Been running a rebuilt 2.5 Sti since April / May after dreaded ringland failure back in February.

Enginetuner did the forged rebuild with all the right bits, Wiseco, K1, Cosworth, RCM, ARP etc etc. Basically the same except for flowed and ported heads - which seemed a good idea at the time.

With a Litchfield/Forge caik, decat H+S downpipe (wrapped), 2nd hand PPP exhaust bits, and Ecutek remap it made a storming 365 / 365. A near identical Hatch with full H+S 3" exhaust made 355 / 365 ... maybe the flowed heads made the little extra on mine.

Worth noting that these vf48 turbos won't do more than 370bhp (regardless of what other rolling roads / delta dash readouts say). So no offence please - do some research. So pretty much maxed out the turbo with the car going very well, aggressive, and so much improved over standard. Plus Martyn did some ecu trickery on improving the throttle response... nudge nudge, wink wink, say no more...

So 3000 miles since build, due last oil change before synthetic (Cosworth earlier this year changed their running in guidelines to 3k on mineral oil then switcharoo to fully synthetic), and due 20,000 mile service - I decided to go once again on the 500 mile round trip to those lovely guys at Enginetuner.

I had been musing having something else down whilst down there, but not having bucks to throw around decided to maybe sort the headers out. So... after speaking to header guru Harvey Smith I ordered a fully wrapped set of RCM tubular headers with one of Harvey's hybrid slip-jointed up-pipes (which gets smaller at the top, supposedly eradicating the later spool characteristics of tubies) - they were delivered in 24 hours ! ! ! Harvey is a genuine legend guys

So car was serviced, last oil change and tubular headers fitted. Car started.... exhaust note snarlier, sharper, and yet smoother too... sounds good.

Martyn master mapper was called upon to work his trickery once again.


Well... an hour or so later we touched nigh on 430 lb torque

thats an increase of 60+ lb at nigh on exactly the same spooling point !!!! ASTONISHING !


After much twiddling at the laptop we couldn't coax any more bhp out of the car - in fact it was 0.7bhp different from last time (that's consistent eh ?) - then we remembered the turbo was maxed out before we started and coudn't make any more power if we wanted it to (and we did) .

But the way it amde the same power level was very different (so much less stress). Initial boost of 1.5 bar at 3400 dropped off very quickly down to 1 bar where 350/360bhp was held until redline. Previously it held boost at 1.49 to 6krevs + , making exactly the same figures with much less boost.

So now the car is 365 / 430 and quite a step up in performance again. Well worth the money BUT I would encourgae you to get the Harvey hybrid up-pipe if you want to keep your spooling low. The RCM standard one has the same diameter all the way = same power proabably but not same spool (maybe 500rpm difference). BTW Harvey rates his up-pipe to 600bhp with no loss in performance.

Alan Jeffries at Enginetuner had told me that the people at Cosworth had made similar claims that tubular headers work particulary well with the hatch cars 2.5 set up BUT it was the first time he'd seem such dramatic increases in torque through one straight forward modifcation. Add to that the fact that these RCM header / Harvey up-pipe combos actually do what they say on the tin (quite rare these days). So impressed were they, that they kept a r/r printout for their records too.

It may be worth saying that my flowed and ported heads helped these figures BUT even if you only got 40-50lb increase it would still be very much best bang for your buck theology.


Hope this helps somebody and PLEASE if my limited knowledge has caused offence - Chill out we're all on a learning curve


FUTURE plans are a new turbo and injectors, more likely to be a TD MD555 420 - 450 special. These turbos fit straight on.... and spool really well, and are not 'salesmen turbos'.


A


PS . Big thanks to Alan, Martyn, and the boys for being there. Top service guys as ever, and reasonable with it too. Highly recommended for rebuilds / advice.

PPS . They also did the DVD player trick for me - took 5 mins.

A week later and a few more 'observations'...

Yes the turbo spools up just as early / maybe even a little earlier - but the duration of spool may be longer ? Does that make sense ? More exhaust pipe to fill ?

And the power is just sublime... you don't honestly realise the way you're being thrown down the road - its just like 'really effortless'. Must admit its addictive...

Then we have the exhaust note... a guttural, slightly raspy howl. Windows down and you known its not your 'average' dugga dugga scoob.

No real difference to fuel consumption... might be a little better.



A

any chance of a video clip?

Hi

Dont have any idea of how to sort a video clip on the web matey....

I'll see if the Blackberry can take one and then email if does...

Shall test first....


A

Would you, or your mapper, reckon these RSC headers and super Harvey hybrid up-pipe ( all wrapped ) would need a remap / tweak?

V

Definately mate. If your engine is valuable to you - tweak the map.

When Martyn at Enginetuner was adjusting the map, initially we saw 400lb torque at first dibs (we were pleased), then after some more minor adjustments 430lb (we were shocked) !

It makes quite a difference. I cant wait to bolt on a big turbo to see what difference it would make... I know 430- 450bhp will come easy, but I REALLY want 500lb torque at low revs lol...

One of the points from the initial post was that the hybrid up-pipe keeps the spooling as standard - without it headers can add 500rpm and narrows the power band. My aim is drivabilty over all-out power, so all the help I can get to keep the power coming in as low as possible in the rev range is a priority.

Worth saying that Harveys wrapped headers look like they were wrapped at Harrods - each pipes painfully and individually wrapped. Many other wrapped headers look like my 5 year old done em. lol

Initially I'm sticking with the top mount, I've seen how badly fitting/designed are the Cossie intercoolers - they can be made to work properly, and the core is good, but they are way overpriced. Maybe Harvey will get himself together and put together a good FMI kit ?

While you're at it, fit the Perrin intake silicon hose (the only one on the market with reinforced steel bands to stop it flexing). Costs £200+ but will lower spool again (by up to a claimed 250rpm) and give up to another 10 of each... so they say. Worth thinking about if you're having a few other bits fitted and the mapping redone.

There are cheaper alternative Headers/ Pipes / Intake hoses but they dont all do what they say on the tin....

A