modification question.. bit thick

[Robert Lees]

As prev post picked tvr chimeara 4.5 up at weekend, the prev owner, done loads to it, but no idea what stuff does. Sub woofer and act induction kit ( with heatsheilding) I'm ok with but what does a plenum spacer do and act engine trumpets ( no jokes! :-)). I'm assuming better air flow? Will this increase BHP :-)
Car flew through mot and had look under it, looks pretty good,chassis still white, no rust but not waxoyled, should I get it done? new front wish ones, braided fuel and brake lines, look like brand new shocks. Having all filters changed and oil swap,, then wait for sun to come out!!

[seeby]

Robert Lees said:

then wait for sun to come out!!

Long wait then !

[debaron]

Robert Lees said:

As prev post picked tvr chimeara 4.5 up at weekend, the prev owner, done loads to it, but no idea what stuff does. Sub woofer and act induction kit ( with heatsheilding) I'm ok with but what does a plenum spacer do and act engine trumpets ( no jokes! :-)). I'm assuming better air flow? Will this increase BHP :-)
Car flew through mot and had look under it, looks pretty good,chassis still white, no rust but not waxoyled, should I get it done? new front wish ones, braided fuel and brake lines, look like brand new shocks. Having all filters changed and oil swap,, then wait for sun to come out!!

Robert Lees said:

what does a plenum spacer do and act engine trumpets

The Plenum (Big sliver box on top of engine in the middle with 450 on) is an air reservoir that supplies air into the engine via the big (ACT Smoothbore in your case) pipe. The reason for this is that the ECU needs to know how much air is going into engine so it can calculate the fuelling, hence a controlled air intake environment. Inside the plenum are the trumpets which (and I'm stretching my knowledge here) help with the induction into each cylinder.

How long they are (and also the height from the top of the plenum to the top of the trumpet) affects the velocity of air into the engine and thus the torque curve (cam overlap I think?) so many people tuning the engine cut down the trumpets or change them altogether (for the ACT ones) to give different torque characteristics. The ACT induction kit is good for a few extra (2-5) BHP on a healthy engine but the trumpets/plenum spacer is more down to torque.

• Please note I may have got the *exact* details maybe round the wrong way but the bones of it are there.

Also, check out the difference between torque and power. Understanding that makes understanding the engine and it's characteristics much easier!

HTH

Ryan

Edited by debaron on Wednesday 18th July 13:23

[Robert Lees]

Thanks Ryan, be interesting to see what figures it is producing after 14 years with the mods included... Am I brave enough to rolling road it??

[Alexdaredevilz]

Robert Lees said:

Thanks Ryan, be interesting to see what figures it is producing after 14 years with the mods included... Am I brave enough to rolling road it??

Best thing to do is rolling road the car, then compression test wet and dry followed by a leak down test and give it a full health check

For example you cam or valve seats might be worn and money would be better spent fixing that or upgrading it

You need to find the best bhp per £