Another Rolling Road Session, Turbo time

[Peter255]

Didn’t realise you had the boost controller Peter, did you get it retrofitted or did you have it from the off?

There isn’t as much of a difference in the curves as I thought there might be. What do you tend to use most of the time?

Fitted when it was recently serviced (1 year old). Not sure which map i prefer yet. Only driven it a few times since fitting. It is noticeably more aggressive though when on lvl 3.

[AMH 142]

Great post Peter and thanks for organising. Some interesting and myth busting stuff.
Would you be brave enough to get out your coloured pens and over trace on your sheets what you think the standard 350 Looks like?
Aidan

[Peter255]

Great post Peter and thanks for organising. Some interesting and myth busting stuff.
Would you be brave enough to get out your coloured pens and over trace on your sheets what you think the standard 350 Looks like?
Aidan

Np. I like to try to get some measured independent data on these type of things rather than just opinions.

The stock 350 map should be exactly the blue power and torque trace +/- 5% (for the RR errors). Ariel have already stated the stock 350 map is lvl 2 on the boost controller. As you can see the difference is the boost comes in harder faster and higher from 3000 - 5000 rpm on lvl 3 with the boost controller. The difference in the maps at the top end (say from around 5000rpm onwards) is likely errors or some other variable and i think can be ignored. The top end should be the same power (which aligns with Ariels comments). In other words Ariel have earlier confirmed if you want the maximum mode you do need the boost controller (which is both un-usual, and a change from the early review cars).

So the boost controller is going to make the mid-range more punchy. I can feel that myself, and its not a placebo. Its a definite measurable enhancement. Its not a huge difference but you can feel it. The counter to that is the boost on lvl 3 comes in hard and this could lead to instability. You either need to be with warm tyres in a straight line or a handy wheelsman as it could catch out the un-wary in a corner or over some poor quality UK tarmac.

The boost controller on my car was fitted specifically so i could get to the bottom of this, and I am glad it was fitted. It is NICE to have the option of "nanny" mode, "smooth", and "aggressive" modes. For scaring your friends it seems like lvl 3 will definitely find some use. Is it worth the asking price? So far IMO probably.

But if money is an issue its NOT an essential purchase, and it may be a hinderance on track when smooth power out of corners is a GOOD thing. The aggressive more "old-school turbo" spool up where torque / power comes in with a bang could end up being a hinderance unsettling the car. Time will tell.

[Preseh]

Very interesting, thanks for this! Does that mean there's potentially quite a big difference between each car? I know Simon's car was a good 30bhp more than yours [mention]Peter255[/mention]. Or is this down to the differences in rolling roads?

[Peter255]

Very interesting, thanks for this! Does that mean there's potentially quite a big difference between each car? I know Simon's car was a good 30bhp more than yours @Peter255. Or is this down to the differences in rolling roads?

The engines are crated from Honda, the upgrade parts are the same, and using the same map. They should all be identical power output give or take a few BHP. However in general rolling roads are notorious for having significant discrepancies between different operators. Indeed you can and do see differences on different days even on the same site with the same operator. I would only use them to compare on the day on the same equipment wherever possible.

I would guess +/- 5% error is common enough and it is well known some places are "generous" with their results. Its much easier to have nice conversations with happy customers after all.

Simon may have got more cooling to the rad / intercooler for his run which would certainly help too. Sadly we can no longer ask him if he has specific extra fans for the intercooler (or similar). There is one MASSIVE fan at SRR and the others didn't fit my i/c.

If the Atom 4 does make 350BHP and Simon had a lucky or generous result (+5%) that could read as 368BHP. If you think about it no-one has suggested its a 365BHP map. Ariel don't advertise it as such. If the cars routinely were 360 why not call it that? It sounds much better than 350. The extra 15BHP is highly likely to be an error. By the same logic I could have been unlucky and read 350 -5% = 333BHP.

We are both within 5% of 350, so probably fine. I would have been concerned if they tested a bunch of identical Atom 4's back to back @ SRR and all the others got ~360 BHP, except mine showing ~330. That would point to something not correct.

I am happy to do further testing if anyone wants to do some more checking with a bunch of 4's. It would be great to do a 320, a 350, and cars with the boost controller back to back.

[CAG3D]

I would have thought it’s a tricky drive on a Track Pete, compared to the older more progressive cars? So much torque at a relatively small powerband, brutal torque. Do you have it on 3 when you tracked it? Easy to get out of shape?


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[nfcf]

So yes the decat does make a worthwhile difference. I will edit out the reg's and post the traces ASAP, vids to follow...

Given Ian's car was noted as running rich I'd not rely on that cat/decat comparison. I would also have thought the K24/K20 would've made more power as the N/A versions can be near 300bhp with right the build.

And a bit of fun.

Handheld noise meter @ 4500rpm @ 45deg 50cm from exhaust tip

Karl's Nomad - 101.3dB
Phil's Nomad - 104.3dB
Peter's Atom - 104.4dB (at the limiter)
Ian's Atom - 116.9dB lol

I seriously hope thats over-reading but as a comparison it should be OK.

Those readings for the Nomad's look about right. The 4 might be high though if you measured it on the limiter instead of just below it.

[Karl V]

[mention]nfcf[/mention] - did you know the Nomads have a green / amber / red flashy light when the revs get high?

Not seen that before wading through mud and grass. Interesting...

[Sir Nick]

@nfcf - did you know the Nomads have a green / amber / red flashy light when the revs get high?

Not seen that before wading through mud and grass. Interesting...

flashy light thing

[Peter255]

I would have thought it’s a tricky drive on a Track Pete, compared to the older more progressive cars? So much torque at a relatively small powerband, brutal torque. Do you have it on 3 when you tracked it? Easy to get out of shape?

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I agree that map 3 could be tricky on track. But thats a guess as the last time on track was BEFORE i had it fitted. It'll be fun finding out.

[CAG3D]

What power were you running on your track day?


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[nfcf]

@nfcf - did you know the Nomads have a green / amber / red flashy light when the revs get high?

Not seen that before wading through mud and grass. Interesting...

I thought the red flashy lights meant you were on a left hand bend instead of a right hand one.

[Peter255]

What power were you running on your track day?

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Stock "350" so hopefully ~350 or maybe 335.

[Toilet Duck]

Excellent info Pete, very interesting read. Good to get some actual figures/data rather than the usual guesstimates etc

Gutted I couldn't make this one, will there be another dyno day in the new year?

Cheers

[Peter255]

Excellent info Pete, very interesting read. Good to get some actual figures/data rather than the usual guesstimates etc

Gutted I couldn't make this one, will there be another dyno day in the new year?

Cheers

Np

If there is enough interest then why not. I will be happy to book it and bring along the 4 to see if we can get some of my 15 ponies back with a bit more air to the intercooler.

Remind me later and i can start another thread.