V8S on the rollers
Discussion
V8S Mark Adams Chipping at Austec.
Just thought I’d post a quick note on my V8S Mark Adams chipping and a little tip to improve performance on any V8S.
A few weeks ago now I had my V8S chipped by Mark Adams down at Austec. Still haven’t got a scan of the results yet, I’ll post when I do but here is a quick summary of the results. Power is up about 10BHP across all the rev range, with a peak up from 211 to 217 BHP. Not a lot, but smoother all the way up to peak power. However the torque increases are stunning, 240ft/lb at 1800rpm up to 257 at 4000rpm, and pretty much flat over the range. The car is now definitely quicker and it feels probably quicker than it really is, with the increase in torque it now pulls in any gear from any rpm. Driveability has increased and it feels a lot smoother. Overall well worth it and a very interesting afternoon at Austec.
Now for the interesting bit (for V8S owners anyway). Whilst on the rollers Mark pointed out that the aluminium intake that runs across the top of the manifolds to the filter gets very hot, and before the final run we had to let the car cool as the power was dropping off. Feeling the aluminium pipe it was indeed very hot. Not a good thing to heat the air before induction, we want it as cool and dense as possible for maximum power. Mark suggested that wrapping the intake pipe in insulating cloth was a god idea and would liberate a few more BHP when under normal running conditions.
So after a week spent blatting around the Lake District in the newly chipped motor and checking the temperature of the intake in ‘real world’ motoring situations it was clear that it got very hot after only short runs and must have been heating the inlet air.
Upon return a quick look around confirmed that Demon Tweeks had just the sort of heat resistant cloth. I opted for the 1.6mm thick figuring the more insulation the better. ( www.demon-tweeks.co.uk/catalogue/product_detail.asp?PCODE=MOCAGC1&GRP=MCP025&PGRP=MC009&CLS=MCYCLE&code=MOCAGC&from=search ).
I simply cut two pieces, as wide as the circumference of the pipe and trimmed the ends to fit around the 90 degree bend then glued them on using a contact adhesive and added a couple of cable ties just to hold them in place.
So far it appears to keep the inlet a lot cooler, and so I guess the inlet air must be cooler as well, hence a few more BHP even when its hot.
Before beginning, the naked inlet:-
[pic] www.btinternet.com/~typevii/no-wrap2.jpg [/pic]
First part wrapped:-
[pic] www.btinternet.com/~typevii/first-part-done2.jpg [/pic]
The finished Job:-
[pic] www.btinternet.com/~typevii/finished2.jpg [/pic]
Adrian.
Just thought I’d post a quick note on my V8S Mark Adams chipping and a little tip to improve performance on any V8S.
A few weeks ago now I had my V8S chipped by Mark Adams down at Austec. Still haven’t got a scan of the results yet, I’ll post when I do but here is a quick summary of the results. Power is up about 10BHP across all the rev range, with a peak up from 211 to 217 BHP. Not a lot, but smoother all the way up to peak power. However the torque increases are stunning, 240ft/lb at 1800rpm up to 257 at 4000rpm, and pretty much flat over the range. The car is now definitely quicker and it feels probably quicker than it really is, with the increase in torque it now pulls in any gear from any rpm. Driveability has increased and it feels a lot smoother. Overall well worth it and a very interesting afternoon at Austec.
Now for the interesting bit (for V8S owners anyway). Whilst on the rollers Mark pointed out that the aluminium intake that runs across the top of the manifolds to the filter gets very hot, and before the final run we had to let the car cool as the power was dropping off. Feeling the aluminium pipe it was indeed very hot. Not a good thing to heat the air before induction, we want it as cool and dense as possible for maximum power. Mark suggested that wrapping the intake pipe in insulating cloth was a god idea and would liberate a few more BHP when under normal running conditions.
So after a week spent blatting around the Lake District in the newly chipped motor and checking the temperature of the intake in ‘real world’ motoring situations it was clear that it got very hot after only short runs and must have been heating the inlet air.
Upon return a quick look around confirmed that Demon Tweeks had just the sort of heat resistant cloth. I opted for the 1.6mm thick figuring the more insulation the better. ( www.demon-tweeks.co.uk/catalogue/product_detail.asp?PCODE=MOCAGC1&GRP=MCP025&PGRP=MC009&CLS=MCYCLE&code=MOCAGC&from=search ).
I simply cut two pieces, as wide as the circumference of the pipe and trimmed the ends to fit around the 90 degree bend then glued them on using a contact adhesive and added a couple of cable ties just to hold them in place.
So far it appears to keep the inlet a lot cooler, and so I guess the inlet air must be cooler as well, hence a few more BHP even when its hot.
Before beginning, the naked inlet:-
[pic] www.btinternet.com/~typevii/no-wrap2.jpg [/pic]
First part wrapped:-
[pic] www.btinternet.com/~typevii/first-part-done2.jpg [/pic]
The finished Job:-
[pic] www.btinternet.com/~typevii/finished2.jpg [/pic]
Adrian.
Those corners look quite horrible from the point of view of air flow, although not as bad as the catted version with the pipe wrapped right round the exhaust. The best solution I've seen is to put the air flow meter and air filter directly in line with the throttle breating from an air box on top of the passenger's footwell. This gives a cold air feed and no corners. I can't give you a direct before/after comparision because I've had so many other changes done, but you could jury rig this very easily for a rolling road test if you want to see how much difference it makes on your car.
Was considering some 'breathing' improvements to my V8S also. Insulating the aluminium pipe is an option that had crossed my mind.
Incidentally, my aluminum intake pipe is a little different to yours Adrian. It is shorter and has a slow, smooth bend.
Also thought about greenv8s's suggestion of an 'air box' at the back of the engine bay in a cooler area. It seems to me that the current intake route is inefficient in that it is not only subject to the heat of the exhaust, but is also very long and not helped by the non-smooth bore of the plastic section of pipe.
If I were to create such an 'air-box', thereby providing a much shorter intake route, would I need to carry out any adjustments elsewhere to compensate?
Also, as the existing air inlet is right behind the grill, would this new position be acceptable as it is not subject to fresh air flow?
Incidentally, my aluminum intake pipe is a little different to yours Adrian. It is shorter and has a slow, smooth bend.
Also thought about greenv8s's suggestion of an 'air box' at the back of the engine bay in a cooler area. It seems to me that the current intake route is inefficient in that it is not only subject to the heat of the exhaust, but is also very long and not helped by the non-smooth bore of the plastic section of pipe.
If I were to create such an 'air-box', thereby providing a much shorter intake route, would I need to carry out any adjustments elsewhere to compensate?
Also, as the existing air inlet is right behind the grill, would this new position be acceptable as it is not subject to fresh air flow?
Interesting article, if this was last week you may have seen mine siting around waiting, for the next round 
.
I had some intersting results on a previous session there. The ali pipe was nearly touching the manifold after being lent on
. When it came to the power run, the air was cooked enough to knock it down to 230/40 
, which when sorted came back up to the expected levels 
.
I can confirm first hand that worse case the ali pipe getting too hot to touch will knock up to 40bhp off onma V8S
.
Peter, very interested in the straight run to the AFM, do you have any pictures/measurents
.
Do use use a bell mouth filter there.
Harry
. I had some intersting results on a previous session there. The ali pipe was nearly touching the manifold after being lent on
. When it came to the power run, the air was cooked enough to knock it down to 230/40 , which when sorted came back up to the expected levels . I can confirm first hand that worse case the ali pipe getting too hot to touch will knock up to 40bhp off onma V8S
. Peter, very interested in the straight run to the AFM, do you have any pictures/measurents
. Do use use a bell mouth filter there
. Harry
If it's not too rude a question, how much did it cost. I was thinking of having some work done when I get my car back on the road, so it would be nice to plan.
Also, my intake is different again, with one bit of straight pipe and the rest all bendy tubing. Mine is ducted around the rad.
Z
Also, my intake is different again, with one bit of straight pipe and the rest all bendy tubing. Mine is ducted around the rad.
Z
z_chromozone said:
If it's not too rude a question, how much did it cost. I was thinking of having some work done when I get my car back on the road, so it would be nice to plan.
Also, my intake is different again, with one bit of straight pipe and the rest all bendy tubing. Mine is ducted around the rad.
Z
Z, you have mail.
Lets just say bank on more than 500 but less than 900, depending on what exactly you have done.
However, it appears that once you start down this road it is very difficult to stop.
Inlet pipes then appear to be made from whatever was at hand at the time, or maybe they were improved throughtout the life of the V8S? (Think maybe I'll plump for the former).
ade
HarryW said:
Peter, very interested in the straight run to the AFM, do you have any pictures/measurents
Do use use a bell mouth filter there
Harry
Been meaning to post some pictures when I find time and bandwidth. In the meantime imagine a box on top of the passenger's footwell drawing air from the high pressure area at the bottom of the windscreen and you will get the general idea.
greenv8s said:
Peter, very interested in the straight run to the AFM, do you have any pictures/measurents
Do use use a bell mouth filter there
Harry
Been meaning to post some pictures when I find time and bandwidth. In the meantime imagine a box on top of the passenger's footwell drawing air from the high pressure area at the bottom of the windscreen and you will get the general idea.
Peter if you have pics i'll host them no probs
deeen said:
on most cars the bottom of the windscreen is a low pressure area...
On most cars the bottom of the windscreen is a high pressure area. The typical pressure trace shows a large high pressure bubble extending about half way up the windscreen and a similar distance forward onto the bonnet. I've also confirmed that for the V8S in particular, air flows into the engine bay through the gap between the bonnet and the windscreen while the car is moving - the flow reverses due to convection when the car is stationary.
I can verify this. My I spy book of high pressure zones has it in there and I have been using it on the 520 for the last 3 years or so. Big big difference. Needed a custom bonnet on the Wedge design to create a nice big 4 inch gap at the back and an enclosed air box for the triple throttle body. Pete actually put me onto this trick.
Worth buying a simply temp guage with a remote sensor in the air flow to see what temps are actually being reached and thus work out how big a problem it is. Can also use it to see if the various changes make any difference. Maplins sell them for a few pounds. The 520 has one permanently fitted now.
Worth buying a simply temp guage with a remote sensor in the air flow to see what temps are actually being reached and thus work out how big a problem it is. Can also use it to see if the various changes make any difference. Maplins sell them for a few pounds. The 520 has one permanently fitted now.
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