is a 4 branch really neccessary with a big valve head? experts needed!

[MarkS]

just shoveing a higher pressure fuel reg in there is sub optimal,  did that on TC's  car just to see what diffrence it made,  it's still in there and it goes fine up top,   that was a 4 bar reg instead of a 3   but on the cold start it runs awful so you should really tweek the fuel map as well

Fair enough!
Didn't really know for sure if it would be an improvement, just thought I'd suggest it for something to look into
What does a high pressure fuel reg do for bhp/torque if anything at all?

[paultownsend]

i was looking at a new fpr, from a porsche 944 i think. but yeah surely if its 4 bar, its 4 bar all the time. and it only needs it at over 4.5k revs. so would be overfueling below surely?

markS- im not sure if 276 will be a bit too much for a road car, and loose that low down power. id love someone who has one to comment

[Diamond Hell]

I'm TC (as well as DH).

The 4 bar reg DOES seem to have made a difference especially over 4,500RPM, but then I'm running a 2E bottom end, with a flowed and mildly breathed on crossflow 8V head, G60 injectors on digi2 with a lambda and a crap map.  On the first session on the rollers the car was leaning out over 4,500RPM.  This was probably due to the map not being able to keep up with the cam and the flow across the head (the map's for a counterflow).

Since then we've slapped the 4.0bar reg into it, just to see what the effect would be (it was five-finger discounted out of an over-priced scrapyard).  The car is now keener at higher revs, so probably producing more top end power, which we like.

As my car is a trailer queen/track slag/garage whore, when it's being driven it tends to spend *quite* a lot of it's time over 4,500RPM which is why I don't mind the car running like a bag of nails when it's cold and idling.

Quote DannyP on the first time passengering with me on track 'you like revs WAY too much for an 8V, you so shoulda gone for an ABF in here'.

Bed made, lie in etc.

[MarkS]

What maps are everyone running?
Are people using aftermarket ecus?

markS- im not sure if 276 will be a bit too much for a road car, and loose that low down power. id love someone who has one to comment

A fair point, hopefully someone will be able to comment
I imagine it is still driveable as it is not a race cam
Also, with an adjustable vernier, could you not tweak it so that the power band shifts down the rev range a bit?

Hopefully someone can clear it up for us

[dubslug]

i have 276 in my daily/weekend car and its ok, bit lumpyin the cold when its on auto choke but nothing u cant handle, once its warmed up it goes like stink, mines a 2e bottom end, big valve head, 276 cam, full stainless exhaust system manifold back
mine leans out way to much in higher revs though, so im looking at improving fueling myself

[danny_p]

was looking at takeing the tweeked chip out of DH's car  and giveing it a hole load more fuel at the top end,  the chip was desinged for tweeked counter flow engines not the crossflow thats in there so it was a bit lame up top till the fuel pressure went up,  looked into it for a while found out how to give it more fuel  but the ignition map is much harder to alter so DH bought megasquirt

[plasticfantastic]

hi all,

Well i have finally been able to take my car for its first blast today,

im running a piper 276, ported polished head, 2.0ltr agg block, stainless 4 branch.

so far she seems great, tickover is almost perfect even from cold. and even good power from low down, but from 3 - 5.5 its awsome! havent really taken her past that yet,

as yet i havent had a chance to put a timing light on her, but as she is ticking over so well would i have much to gain?! having mot tomorrow so will check the co level, and will be fitting a new blue temp sensor ready for a r/r session at some point.

i must admit i was expecting a little more from it, but its ealy days with alot of tweaking ahead!

cheers

[paultownsend]

plasticfantastic, what manifold did you use? and clearence issues?

[plasticfantastic]

i used one from these off fleabay

http://shop.ebay.co.uk/merchant/tuning-center-kassel_W0QQ_dmdZ1QQ_ipgZ50QQ_sopZ12

they dont have one listed at the mo, but cost me 150pound delivered! well happy at that money.

no clearance issues at all, even on the 2ltr block, but i did raise my front mount by about 5mm.

did need to grind the inlet manifold a little, and definatley wouldnt fit it with the head in the car, take it off and do it on the bench!

sounds awsome, actually quite quiet, i made a custom centre section from 65mm tube and reduced it down to 45 to match the standard 8v rear boxes, but im now wondering if these may be restricting my engine especially top end?!

cheers

[paultownsend]

thats the trade off with the exhaust. the oe vag system i had on mine was absolutely silent.loved it. but REALLY reigned in the top end. trying to find a compromise