2008cc 8.75:1 CR 3A G60 build.

ctwg60 wrote:The reroute.

Sure mate, will get one sorted later - it's a bit scruffy at the moment, but does the job....

yep.

Here you go....
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The ISV is rerouted into the inlet pipe. Where it was originally connected to the return pipe to the SC, I cut off the connector, glued a flat plastic plate over the hole, and then used filler over that. Belt and braces approach, but as there was up to 1 bar pressure above atmospehere going through there I wanted to make sure it wouldn't come off/leak. I have a silicone pipe to replace the one I cut, but rather than cut that I am going to use one the of the Revotech screw in attachments for getting pipes into silicone.

OK I see, good solution. I'm going to try a non return valve (£10) and see if there is any difference in boost. As I said I tried lots of ISV's last night 2xPB and another PG ISV. Each gave slightly different max boost and boost build characteristics. So certainly something to consider!

I've tried 2 ISV's on mine, and yes, they give different boost characteristics. The ISV can also be adjusted using the small hex screw in the end. But of course it is difficult to know waht to adjust it to as you have to do it while disconnected from the loom.

jmc wrote:I've tried 2 ISV's on mine, and yes, they give different boost characteristics. The ISV can also be adjusted using the small hex screw in the end. But of course it is difficult to know waht to adjust it to as you have to do it while disconnected from the loom.

I never knew that.
Cool.

Shouldn't be too hard to work out which direction is closing and which direction is opening the valve.

I wondered what that was! Ha good info!

Ha! J808 had a present for me today. Messing around with some one way vaccum valves today I decided to use the return hose off of J808. It felt like it had something stuck in it! I blew through it and couldn't. I sucked and I could! Ha someone had already shoved a oneway valve into the hose.

I fitted the hose and went out for a blast. I can hit 1700 at 3k and at the red line 1770. Best I've seen yet, then ran out of petrol and had to limp to the petrol station. So it feels pretty sorted now! So 10psi by 3k and 11psi at the red line. I think that will do for a stock charger running a 65mm on this engine! Still need to static pressure test the engine though. Think I'm going to cut the air box and remove the carbon can and duct some air from below.

Nice surprise!

I messed around with the adjuster screws on an old pb isv and although I got it give me a bit more peak boost I quickly came to the conclusion that these valves aren't capable of closing fully. So a one way valve seemed like the right solution. Handy to have a free hidden one!

So 1700 hg is 11 psi?

Funny you should ask that, I've just been wondering the same thing. I've been using the matey-matey chart to workout the conversion but it's totally wrong!! It's states that 1000#hg is ATM pressure! It bloody isn't! 760 millimeters of mercury is ATM so 1760 is 14.5psi above ATM! WTF! I've been working of this crap!

EURO Hg(#'s of boost/vacuum)

200 - 23.7
400 - 17.8
600 - 11.9
800 - 5.9
1000 0 (Atmospheric pressure, charger is bypassed?)
1200 2.9 psi (You have a major boost leak)
1400 5.8 psi (Your charger is in very poor condition)
1600 8.7 psi (Your charger would benefit from new apex strips)
1800 11.6 psi (Good for stock pulley, needs new apex strips if 68mm pulley)
2000 14.5 psi (Good for 68mm pulley on stock charger)
2200 17.4 psi (Good for 68mm pulley on heavily ported charger)

They call it euro hg!! I'm assuming this is mm of mercury! What!!

EDIT: [You must be registered and logged in to see this link.]

Intake Manifold or Charger Boost Pressure conversion Table:

MFA Readout Motometer/mbar in. Hg

15 200 23.7

55 400 17.8

90 600 11.9

127 800 5.9

148 1000 0

172 1200 2.9 psi

192 1400 5.8 psi

211 1600 8.7 psi

228 1800 11.6 psi

242 2000 14.5 psi

255 2200 17.4 psi

Confusing again! Column 1 KPa Column, 2 millibar, Column 3 psi. But why does it mention hg?? in hg! WTF!

EDIT 2: Bentley says mbar! OK back on track now!

I asking santa to get you a boost guage for christmas.
I'm gonna tell him to fit it in your car while you sleep.

Thanks Rob but I have one on order already.

J808 has turned up a few interesting things.
One way valve fitted and a 68mm pulley.
I was lead to believe from the previous owner that he wasn't an enthusiast.
Odd.

Still toying with the idea of a one way valve from the engine block breather on mine to the boost return.

For my own ref:

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Ahh good idea! I'm going to use the the one way valve on order from my block breather to the open air side of the airbox but wonder if the oily vapour would bother the paper air filter.

ctwg60 wrote:Ahh good idea! I'm going to use the the one way valve on order from my block breather to the open air side of the airbox but wonder if the oily vapour would bother the paper air filter.

go via a catch tank?
Maybe keep an eye on it,see how heavy the engine is breathing.
Where did you get the one way valves from?

guy on ebay is selling them and he providing rubber hose adapters for it.

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ta.

OK tonight with it being cold and foggy I gave it some and saw 1660mbar at 2500rpm hahaha and then 1730mbar from about 3-3500rpm and then a peak of 1810mbar at 6000 before the rev limiter at 6200rpm! HAHAHAHAHAHA!!!

So I've managed to go from 1640 when it was attempted to be mapped (days later this dropped to 1440) to 1810. So effectively gained 2.5psi taking me from 9.3psi to 11.75psi, never mind 6.38psi when it was knackered. Trying to get in touch with Wayne now, if i can't by Friday i'll have to take a trip up there.

I like mbar and psi.
Ok sounds good.Sounds like you have been pi$$ing in the wind for a while.

Yep, didn't pay attention to boost piping and have been running to stand still for a while. I'd love to know what the stock head would of done with all the possible boost leaks fixed! See if i can find another this Friday! It's my new hobby!

Replaced the cam pulley this morning. Wobble gone! Left the original middle on there and then just swapped the outer. Still can't run the cam cover though! Never mind, I'll remove the bottom cover when I get chance or modify the top cover to clear the adjuster bolts.

Just need to...

1. Removed carbon can
2. Mod air box
3. fit new charger belt
4. check for more boost leaks
5. Get in touch with Wayne
6. Cross fingers

ctwg60 wrote:Replaced the cam pulley this morning. Wobble gone! Left the original middle on there and then just swapped the outer. Still can't run the cam cover though! Never mind, I'll remove the bottom cover when I get chance or modify the top cover to clear the adjuster bolts.

Just need to...

1. Removed carbon can
2. Mod air box
3. fit new charger belt
4. check for more boost leaks
5. Get in touch with Wayne
6. Cross fingers

What are you doing to the air box and are you running a fully standard one at the moment? The reason I ask is that I did a back to back test on SRR dyno with a normal air box vs one which had been cut on the bottom half and had the trumpet removed. The cut one gave significantly more power and torque (may have pics of the graphs in my build thread if I have been good enought to upload them). Hence for a modeified G60 I can thoroughly recommend modding the lower half of the air box and putting in a cold air ducting feed from the back of the lower bumper. Air supply becomes a real issue at the types of powers you'll be reaching.