Need help - Tuning

[Hallowenman]

So I am making a engine to fit the V8 Supercar regulations. I have made a engine at 5 litres which can produce way more than 650 hp (maximum amount of hp according to rules and regulations.) The only problem is that the engine peak power is at about 8400 or more, depending on my settings. In the real life V8 Supercar series all engines are limited to 7500 rpm. I can still get over 650 hp if I limit it to 7500 rpm, but I feel like the peak power should be at 7000 rpm, so you got some 'overdrive' or what you would call it.

How can I get the peak of the power curve down? I have plenty of RON to go on, but I can't lower the Cam profile a lot due to the fact that it will reduce the amount of hp too much. I can't increase the compression either, because the regulations doesn't alow higher compression than 10:1

Any tips?

[Der Bayer]

Negative top end quality could do it.

[Hallowenman]

That did help! I'll keep working on it now and post updates here if I encounter anymore problems

Thanks!

[pHanta]

How about your ignition timing setting? Is it already at 100 ?

[nialloftara]

Dropping the exhaust diameter a tick or two might lower it a bit though the trade off is a drop in torque at the top end.

[KD14]

What i find annoying at the beta testers here is that sometimes their advises of tuning is to make the engine less good, im sorry for the offence but its kind of annoying to see when there are other much better solutions.

To bring the power band backward in the rpm range, lower the cam profile and\or put a smaller turbo, then play with the ignition timing through the range (i'd say dont go below 50) until you get a nice flat power band. Yes it takes some time to find it but with the time you will notice a couple of spots in the range that always flattens the power band depending on the cam profile. And yes bringing the power band backwards means less power but sometimes more torque.

[nialloftara]

He was looking for other means of lowering peak power without dropping the cam profile, v8 super cars do not use turbos so that was never a option. Try reading the op before telling us how to tune.

[KD14]

I read it all already, the turbo was just an example regardless of the regulations.

Now just to make sure i tested it again and i still say, lowering the cam profile and fiddling with the ignition timing will always bring better results then lowering the head quality, no matter what you are looking for (unless you are looking to make it intentionally rubbish).
By lowering the head quality, you drop the hp in the whole rpm range, not just at the peak. When you lower the cam profile, you lose the same hp for the peak backward movement, but you gain some of it back in the lower rpms and you end up with a wider peak.

[Der Bayer]

He wrote that he didn't want to change the cam profile, I gave him an alternative solution. Nothing more, nothing less.

[NormanVauxhall]

I don't know if you have chance to do it (or if you want to do it), but increasing the bore usually reduce the peak power RPM. It means a bigger size engine and an heavier one.