Originally Posted by Roelof

The EFRA had for 1 year the rule to use an 8mm restrictor, due many blown Picco engines the rule was scrapped after a year. The 16% rule is for 2 reasons, the anti terrorist laws making high nitro content fluids difficult to get and noise and the noise from which we have never seen any test results.

The funny thing with the EFRA is that there are no testreports at all. Not of the homologated exhausts, not of the batteries, not of the bodies etc.
With all noise restrictions the EFRA did not show us the testresults of what the change will give. Even with the 30xx exhausts the only story from the EFRA was that it does not affect engines and there could be a slight power loss. In that year the engines did become hot and some exhausts weren't even giving a good power. But over 40 30xx exhausts were homologated with in a total of about 15.000 euro is earned with the homologation.

The last compleete drawing of an EFRA exhaust was from the 2052, all later models are not listed in drawings and dimensions. How can a technical inspection see or test if it is the right exhaust?

Originally Posted by Maximo

I would be more then happy to dyno test any of your engine combo's and let the results epak for themselves...7mm, 8mm, 9mm, INS box no INS box....5 port GT, 9 port doesn't matter.....thats why I built the dyno to begin with

Originally Posted by MantisWorx

how are you loading your dyno? eddie current, wheel or brake?and does your software compensate for downforce, drivetrain loss etc etc Owning my own Dynojet 1:1 chassis dyno i find it hard to see what freespinning a nitro engine up to max RPM without a real life load on it can do really much good other than comparing just those numbers.

Originally Posted by Maximo

its a inertial dyno, there is nothing free spinning....... the results are very accurate for measuring engine output..........as I say a 7MM insert murders power.....INS box hurts power....these goofy 3 chamber pipes hurt power.........Do you enjoy the idea of choking back your engine ? why are you defending this 7mm rule so much ?

And if your not forced to why run a INS ? enjoy slowing your engine down ?

Originally Posted by MantisWorx

I am not defending it at all i think its Stupid as hell. I just dont think going from a 8mm to 7mm venturi is equal to 20% power loss.

i dont run a 5 port, pipe is "illegal" and my INS box is modified so its not choking anything ( i have a 3d printer!!)

Originally Posted by Maximo

I will dig up a few of the dyno reports....I think your going to be surprised how much a 7mm can hurt the performance...

Originally Posted by Roelof

OK...

I have been at several EFRA AGM's and the EFRA wants to lower down the noise for years. Something they are failing for many years by approving loud noise exhausts. But with one AGM they come up with 2 thoughts to lower down the noise in the future:

1) forbid AAC engines because the aluminium sleeve is making more noise.
2) max 5 port engines because less ports is making less noise.

Both to my knowledge picked out of nothing. I asked if they can show me a test based on 2 same engines with one AAC and the other ABC, they could not. Also as I was running modified 5 port engines I shared my knowledge that my 5 port engines were not making less noise than 7 and 9 port engines.

These thoughts of the EFRA never came back on the agenda, but it shows how stupid organisations can be.....

Originally Posted by beebone

Alright, I test different engine on my GT, Buggy engine makes car easy to drive because of low end torque. GT engine needs proper clutch adjustment to reduce low end stumble and stall. On road engine needs extremely late clutch engagement to get the right low end torque, I think the 8 or 9 mm insert help to bring the torque earlier right? But the run time.

Originally Posted by MantisWorx

Great, i look forward to seeing that!
PM me , i have something you may be interested in especially if you are serious about getting into the engine game.