New owner of a 3.5R from Sweden.

[Bybarth]

Made some footrest whit inspiration from the Atom 4

I will also build a small one beside the clutch pedal.

20200215_122735.jpg (3.63 MiB) Viewed 636 times

[Bybarth]

Was also Lucky enough to get hold of a set of Tillet seats

20200212_101600.jpg (4.91 MiB) Viewed 635 times

[atomiser]

Yep. They really hold you in well and are not uncomfortable compared to the standard setup.

Not sure if those have the adjustment handle but that would be another bonus.

Sent from my SM-N960F using Tapatalk

[Peter255]

Those seats look EPIC.

Have you had it on the dyno / rollers yet? Any gains from your mods?

[Bybarth]

Yep. They really hold you in well and are not uncomfortable compared to the standard setup.

Not sure if those have the adjustment handle but that would be another bonus.

Sent from my SM-N960F using Tapatalk

Yes they do

[Bybarth]

Those seats look EPIC.

Have you had it on the dyno / rollers yet? Any gains from your mods?

No not yet, it's winter now so I will put it on the rollers in the spring.

[Bybarth]

JDM Racing.jpg (1.39 MiB) Viewed 549 times

So, now I have driven the car on a dyno.
As expected, it was not so impressive ...
I was skeptical if it really had the 350hp that Ariel claims.
It performed only 300hp and 320NM.
We couldn't do anything since we were missing the Hondata box unfortunately.
My car has a K24 engine from the factory as mentioned before, but it has a K20 crank pulley and a 3 "charger pulley and gives about 6 PSI.
I have now ordered a K24 crank pulley which is larger and also ordered a Hondata box so we can see what is happening and optimize everything.
Hoping for about 2-3 PSI more and with a little optimization then maybe we can reach the promised 350hp ...

[Anon]

Silly question, but are you sure it's the 3.5R and not a 3.5 with R features i.e. coolers, pods etc.? I don't know the specific's of what makes a 3.5R from an engine perspective other than the oil and charge coolers but I know there are other things Ariel do to the engine/supercharger for more power - maybe larger pullys? It's just 300bhp would make it more inline with the standard 3.5 with the supercharger.

EDIT: also 6psi doesn't sound right. If memory serves correct, the 3.5 supercharged engine was around 7.5psi and the 3.5R option increased it to around 11psi or so. By comparison the Atom 4 has 1.3bar of boost in standard form - I know they are different engines, so 6 psi seems very low. I don't have a 3.5 so I could be wrong here and I am sure others will chip in who own this Atom.

[Bybarth]

The car was sold new in Sweden as a 3.5R.
Acording to Ariel the few K24 3.5R that was build they reduce the boost from the K20s 11 PSI to 9PSI due to intake temperature.
But they still stated 350hp...

[autobackup]

I think Sir Nick has some experience in this area as his 3.5R has the K24 engine fitted and, if I remember correctly, was somewhat disappointed with the results when it was tested at a Atom Club dyno day?

I have the K20Z4 engine in my 3.5R and it also has a ceramicised exhaust system (inside and out) and when I put it on a dyno here in Cyprus it returned 362.3bhp.

I can also confirm that the s/c pressure is set at 11psi in my Atom 3.5R.

I think that one of the problems with getting more power from the K24 engine is something to do with the exhaust port design which is why a K20 head is sometimes married to a K24 block?

[Peter255]

Bybarth,

Have you dropped Ariel an email? I know the factory is closed but they might respond to an email. Your car putting out the same power (300) as a stock supercharged car 2ltr or 2.4ltr is clearly not correct.

The supercharged 2.4 without the charge cooler should be 300BHP. The "350 upgrade" as fitted to your car is not cheap and it should add something! It is true that we have not seen test data for the 2.4 engine with the 350 pack make the advertised figures, but we have (before your car) only seen one other on the rollers.

If you have access to the clubroom section on the forum check out the rolling road results there for comparison (you will need to be a club member). Other cars with different engines have returned the suggested figures so something is definitely wrong here. For comparison my old Atom 2 returned just over 300BHP and it was higher miles and well over 15 years old.

Good luck. I hope you can get this resolved. I wouldn't be happy with 50BHP down on the advertised power. We are planning another club rolling road day later this year when our COVID 19 lockdown is lifted to get some more figures for your info. You are not UK based otherwise I would suggest you come along.

Peter

[Bybarth]

I think that I got som belt slip, because last autumn I sawn 8PSI roughly.
The tuner also thought it was running a bit lean.
So whit a Hondata unit we could fin tune everything and also try a K24 crank pulley.

Another question.
I'm going from 5.75" to 6.125" crank pulley.
Today I got a 52.95" belt (1345mm), any easy way to calculate to get the right belt?

[Sir Nick]

From what I've looked at, you would need a 7PK 1400 belt for the larger crank pulley. This would mate with the 80mm sc pulley.

[Peter255]

[mention]Sir Nick[/mention] and [mention]Bybarth[/mention], you guys need to work together!

Between the two of you I am sure you can work out the best sensible tuning options for your engine.

Bybarth, If you've not seen it check out IanG's thread > viewtopic.php?f=1&t=17546. He has built and tuned a hybrid 2.4 block with the K20 head to 340ish without the charge cooler pods.

[Bybarth]

Thanks for replays guys
I was thinking of go for E85.
I need like 1000cc injectors I guess, but the stock 650cc injectors has a connector that's not available it seems?
Anybody know about connectors that fits the oem loom?

20190916_154027.jpg (3.03 MiB) Viewed 411 times