True and that did put a huge smile on my dial hahahaha
thanks for all the advice guys. Iāll let you know how I got on after I persuade the finance director (aka āthe wifeā) that this is a necessary mod and not another toy for the boys. Iāll go do a test drive of some the BBR stock cars with various mods, but at this stage I think Iāll just opt for the change of ECU and 421 catted manifold. My main interest is to get more power at lower revs, especially when accelerating to overtake and to not get left behind at the lights.
The power curves show the max power achieved at a certain rev. Push (or suck) in less fuel and air then you will have less power. Think about driving up a hill at 70mph at 3200 rpm in 6th gear, going over the crest and down the other side. To maintain a constant 70mph you may be using 100hp on the way up the hill and only 10hp on the way down.
The driver controls the power output by restricting air and fuel through throttle control.
It is possible to get a power improvement at the rear wheel without using additional fuel, by optimising burn, reducing friction, improving air and exhaust gas flows and other power robbing losses. But often tuning simply allows the engine to breath more fuel and air in, this means you will burn more fuel and have lower MPG IF you use that extra power. If you donāt use the extra power, then you may use less fuel to run at the same level of performance IF the engine is operating more efficiently following the tuning.
Lots of people like pops and crackles from the exhaust that comes after tuning. 99% of the time this has nothing to do with performance. It is just getting the computer to push fuel in that doesnāt get burned during the power stroke and burns in the exhaust. So this decreases MPG very very slightly, but does nothing for performance.
thanks for the explanation. I now understand. What you are saying is the power required to move at a constant speed on the straight or up the hill or down, is the power required. How much fuel is used to deliver that power depends on the efficiency of the engine. The power torque curve shows the maximum power that can be delivered at that rev. So when overtaking, either putting your foot down and/or changing down will enable more (maximum) power to be delivered, and so should enable one to accelerate more quickly to overtake. Have I got this right ? and thanks again. The key thing is the power torque curve is not the power that is being consumed at driving at that speed, but the maximum power available at that rev.
Yes you have pretty much got it, but be clear that there is a power curve AND a torque curve. The two are different.
If you want to accelerate you need torque. By dropping a gear you change the leverage between the engine and the driven wheel, meaning you change the torque available at the wheel, so for maximum acceleration you generally want to be in as low a gear as possible. Obviously as you accelerate you run out of revs and have change up a gear. (Also, torque and power will decrease as you ārev outā and there will be a point in some vehicles where changing earlier will be faster than reving to the red line.)
Power allows you to maintain a speed, torque is what allows you to get there.
If you have a revy small 2stroke engine, you will likely have a narrow power band, so you need to dance on the gears to keep things on song.
If you have an enormous v8 with stump pulling torque, you can just pop it in a high gear and leave it there.
Both engines could offer the same peak power, but the way they deliver that power dictates how they need to be driven.
I had the catted manifold Super 200 done 3 weeks ago. MPG on the 180 mile journey back home was no different to before. Regarding the exhaust, the middle section is standard, and hooked up to the Larini backbox is very loud under loadā¦too loud unfortunately! Iām waiting on delivery of BBRās exhaust tips that come as part of the package as they didnāt have them in stock to go on the stock backbox Iāve kept. I find performance is increased throughout the rev range, more so over 3000, but donāt expect ākick in the pantsā acceleration, itās subtle but definitely there. My only problem now is actually using it without the Mrs whinging and telling me to ācalm downā. My insurance, fully comp, was Ā£149 and is now Ā£250.
Wow,
So are you saying that you have basically spent the best part of Ā£3000 
on something that you are not āreallyā happy with, (Fitting, vat, insurance and whatever else)?
Is that question aimed at me?
If I get sufficient more acceleration not to be left behind at the lights with Trabants, and to be able to overtake those idiots who put their foot down when you try to overtake them, Iāll be satisfied. Iām hoping the ECU remap and 421 catted manifold change only will not result in more cabin noise. Thanks for the info on insurance hike. Iāll check with my company in due course.
Hi yes it was, (but thought I hit the reply from your post but didnāt).
Just curious as your over all thoughts.
Post31
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Iāve no problem with the fitting, Iām not sure what you mean about vat, and at Ā£250 I donāt think the insurance is too bad. I was paying Ā£230 three years ago, itās just that the Ā£149 I was paying before the upgrade was super cheap. The noise was always going to be a concern as it was perfect for me beforehand, so it was a trade off between that and performance. Itās ok when bimbling about town, but when you put your foot down over 3000 revs it courts unwanted attention. Maybe itās me getting old as the wife doesnāt think itās that bad and we should keep it, which we probably will as it would really bug me to think someone else has my Larini.
Post 33
100% agree. With my son at the wheel, our upgraded NC BBR Super 200, passed (safely) 25 other cars in one 20 min track day session. I counted. 
The downsideā¦ I always needed to take a spare set of pads to the track. 
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My insurance is Ā£350 without any mods or points haha.