Mike RT4

I have hankered after an S2000 for quite some time and did months of research on here before settling on a 2005 facelifted UK model (F20C engine, with AP2 chassis, body and wheel upgrades) back in March 2016. This is the cable throttle version of the F20C, before the DBW.

Being a serial modifier, I knew it wouldn't remain standard for too long and I have big (but subtle plans) of which will gradually get posted here.

These are the photos from the original advert. When I picked it up it had a smidge under 42k on the clock, so a nice low mileage for the age:
















Knowing it would be used on track required some immediate upgrades which consisted of brake fluid (Castrol SRF), stainless-steel braided brake hoses (Goodridge), new discs (Pagid blanks with a custom groove design copied from APs discs) and Pagid RS29 front pads:









I had also read about the oil surge issues that these cars suffer with, so bought a sump off eBay and had it modified to prevent such a catastrophic event from occurring:





At the same time all the oils were changed (engine, gearbox and diff), just for piece of mind (although it looked like it had been well looked after as the full Honda history seemed to show).

Within a few months I felt that the noise was a little lacking, but not wanting the drone reported with the majority of exhausts (plus having read that there seemed to be very little gains in this area), I opted for the "UK mod" with 25mm sections:











Although not particularly high grade material, I was pleasantly surprised to note that the factory exhaust is actually stainless-steel.

Next up was to see what the base power figure was. I had heard from a tuner friend of mine that these cars are much like the E46 M3s and never quite make the claimed manufacturer's power, with as low as 210bhp @ the flywheel being seen. I hoped that with relatively low miles, mine would be a good one and was relieved that this was so. Absolutely bone stock engine:



218.8 bhp @ the flywheel (182.8 bhp @ wheels)

In my internet research I read that the best "bang for buck" was to fit a test pipe, which allegedly would also give a rise in decibels as well (again without the dreaded drone), something which the UK mod had failed to adequately do (coming from a CSL with a full Supersprint, which is a ridiculous 106dB static ). I sourced a cheap eBay item, fitted it and then went back to the dyno:





224.9 bhp @ the flywheel (189.2 bhp @ wheels)

Not only was the increase in power a surprise, but the added noise was spot on. As quiet as standard off throttle, but with a lovely deep angry sound in VTEC. This is without any tune, as it is still on the standard ECU. I understand that with a full tune (sadly requiring a standalone ECU - much later), that I can expect a big increase in the mid-range from this set-up. Obviously at this stage, it is still 12bhp down on the claimed figure, so not sure where the missing ponies are, as it seems a very healthy example (as an idea, Matt's car (he of huge turbo and Quaife sequential gearbox fame) only made 225bhp on these exact same rollers after full exhaust, Password JDM intake and a full remap on an AEM ECU (admittedly with 30k more miles under the wheels)).

Next was to update the seats, as although quite nice for an OEM set up, they're not grippy enough for track use. Luckily I had some nice Recaro Pole Positions that were removed from my last car before I sold it, so were effectively a free upgrade for the car (man maths ) apart from the seat rails that were required:



The driver's seat was easy, as it was the ABE version with the large seat belt hole, but the passenger one is proving a bitch - spot the difference:









As I had originally ordered these seats a couple of years apart, and was using harnesses in the other car, I hadn't even noticed the difference (I never sat in the passenger seat LOL) until I tried to fit them in the S2000. So at the moment, it is just the driver's seat until I find a suitable solution to this problem:



One of the previous owners had the car set up by Centre Gravity including a full check of the standard corner weights. It has then been set up for a mild "fast road" set up, which seems to be okay at the moment for the standard suspension:
Front:
Left: Toe: zero, Camber: -0°57', Caster: +6°20', Corner weight: 309kg
Right: Toe: zero, Camber: -0°57', Caster +6°19', Corner weight: 300kg

Rear:
Left: Toe +0°25', Camber: -1°31', Corner weight: 331kg
Right: Toe +0°25', Camber: -1°30', Corner weight: 311kg

Total weight (which includes 9kg of additional fuel ballast): 1251kg

With the de-cat pipe being considerably lighter, it will be interesting to see what it ends up at once the Ohlins have been fitted. Will also be interesting to see what a few years have done to the settings as well.

On track it is an absolute joy, completely balanced and throttle adjustable and despite the comedy body roll, it loves to rotate :











At this track day, I did have an issue with the cheap eBay test pipe, but that was down to me fitting a heavy "CEL light defeat" spacer that was too much for the thin wall tin-can metal of the "test pipe" was made of:





I have since modified it to try and ensure that it doesn't do it again:





At the same time we had it on the ramp refitting this, I installed the Spoon Rigid Collars for the subframe and some rear diff collars as well. This transformed the handling without transmitting too much NVH. There is some extra buzzing through the transmission that wasn't there previously (especially at high rpm on the over-run), but this is a trade off worth accepting for the improvement in the handling. Gone has the propensity for the rear to lurch or feel luck the tyre is tucking in or folding on the rim.

I then bought the J's Racing strut brace, not because I felt that it needed any more rigidity, but because of the mounting for the ETD. The gear change is now much more precise and shift quality is much improved. I can't feel any difference regarding the chassis though:









This brings us effectively up to the end of 2016, where I had the following on order, but not fitted.
Ohlins suspension (arriving mid Dec) with 10kg rears
Axialflo quick-shift (arriving imminently)

I also purchased a set of rear AP2V1 wheels to go on the front. These needed to be machined to the 70.1 centre bore and then refurbed, where they were fitted with 245/40 x 17 AD08s all round (I want it to look standard at a quick glance, hence why going to the trouble of doing it this way). I also bought a set of 15mm hub centric spacers to ensure the fronts will fit without catching on full lock and this is the winter upgrades complete ready for the trackdays to begin in February.



I also have the Spoon steering rack bushes and they will be fitted at the same time as the suspension.

I'd like to go Haltech ECU and a J's Racing intake, but might just fit a scoop and gut the standard airbox which according to Gernby is supposed to yield very good results.

Mike RT4

This brings up to Christmas 2016:


Rear dampers built up to correct 10mm pre-load with Eibach 10kg rear springs.

Being lazy and not wanting to strip out the boot interior every time I needed to adjust the damping, I opted for the adjustment extenders.

Obviously the fronts look like everyone else's Ohlins, so no picture .

As you can see from the above pics, I opted for SBG's recommended 10k rear springs and 10mm preload. Due to time constraints and vacation over the Christmas period, I fitted the rears first. OH. MY. GOD, What a revelation, the ride quality AND comfort with the mixture of Ohlins rears and OEM front dampers was brilliant. No more hitting the bump stops, it was just joyful in the way it ironed out road imperfections and was everything I imagined and had read about (and was indeed MORE comfortable than standard). On this basis, I couldn't wait to fit the fronts and finally did so a week or so later. Naturally I was expecting the same improvements and although the handling seemed to have been firmed up even more, it lost some of ride comfort quality it had with the OEM fronts.

It now "feels" aftermarket, where with just the rear Ohlins fitted it felt OEM+ (as in what I felt the S2 should have been from the factory). Unfortunately the roads here in the UK at that moment were cold, wet and greasy, so I was unable to push the car. With all four Ohlins dampers fitted it was firmer than standard and with a reduction in ride comfort over the OEM springs and dampers and with the mixture of the two (although the rears don't hit the bump stops).

However, my reason for this post is that I "think" Ohlins have got the spring rates spot on, just the wrong way round . The 8s should be on the front and the 10s on the rear. Given my experience of running the mixture of the two set-ups, I believe that this "might" be the fix for the ideal ride handling / comfort compromise.

I have since seen that the original Amuse car actually runs this kind of set up (harder rear springs than on the front, albeit stiffer F12k R14k).

Mike RT4

This brings us on to February 2017, where the square set-up wheels and tyres were finally fitted. What a mission that was, I had to change all four bearings and getting the hub nuts off nearly broke the bar as we had to use a 7ft length of 2" box section to crack them. All to fit some longer wheel studs to accommodate the 15mm spacers . What a poor design - Cossie ones can just be pushed out on the car .

I was warned on S2ki that the AD08s would not be as good in the wet as the RE50s, but my experience is the opposite. They offer far more grip in these conditions than the Bridgestones (although my RE50S were almost down to the wear indicators). Obviously I am talking about the damp greasy conditions, not full on water moving scenarios, as then that is what you would expect, as the tread on the Yokos are new compared to my worn RE50s. However, the Yokos are also better in standing water as well, but as stated, that was to be expected.

Previously it would slide really nicely in second gear in damp slimy conditions from relatively low rpm, but now with the AD08s fitted it requires much higher rpm to get the rear moving or some serious provocation.

The extra grip the tyres are giving means that you can actually feel the diff working as the tyres load up and are on the cusp of spinning (you can feel it shuffling the grip from side to side as it locks and unlocks balanced on the throttle). This actually means you can drive far harder in these kind of conditions than I would have ever dreamed of doing with the RE50s. But the flip side of the extra grip is that the car isn't as much fun in this weather, as the breakaway point is that much higher and so I am much more reluctant to push it to slide as the speeds are higher (and I don't want to crash it LOL).

I now can't wait for the next track day (Bedford on the 25th Feb) to see how they fair with some proper heat in them. Regarding the square set up, it looks good, but you can feel the extra weight of the wheels and tyres up front, as the 8.5" wheels with 245/40 tyres are 3kg each heavier than the 215/45s on the 7" rims, so the extra width and weight means you loose the delicacy of the original set up. I have also gone more aggresive on the geo (thanks to Andrew Hake for the recommendations), which means the car follows imperfections far more and makes the steering a bit more "busy".

Hopefully the extra front end grip on track will outweigh the down sides, but until I refit the 7"s (with AD08s as well), I don't know how much of this heavier steering feel is down to the extra weight and grip of the wheels and tyres or the aggressive geometry (up from almost 1° neg to just over 2° on the front). The rear was also set to 2° with 1.5mm overall toe-in and the front parallel. We corner weighted it as well, and it is a lot heavier than previously, as this time all the fluids were at the max (I had just brimmed both the fuel and the washer bottle (this part due to the weather at the time)), where before it was measured on a half tank of fuel.



A good balance, but makes me realise just how heavy this car is (my CSL is only just over 100kg heavier and that has four seats...).

I think I will need to adjust the ride height a fraction, as the fronts "just" catch the outer archliners on big compressions. It is currently 635mm from ground to arch on the front and 655 on the rear - I think 5mm more on the front will "hopefully" cure that (sad, because it does look nice like this).
There was finally a weather window that enabled me to clean the car :

The wheels have been painted a brighter Audi silver (Brilliant Silver L8Z8):


































At the end of February 2017, I then did my first track day with the new suspension and wheel / tyre combo:

Unfortunately it was wet, but the car excelled beyond my expectations. Despite being vastly underpowered, the adjustability and linear nature of the power delivery (no torque to be able to break traction LOL), made it far easier to drive fast in these conditions than lots of much more powerful cars on the day.

The square set up meant that there was no understeer other than on some really slow speed and extremely greasy corners, but boy does she like to rotate. The OEM torsen diff is very snappy in the way it operates. The initial lock-up is perfect, but because my car is standard, if it drops out of VTEC and suddenly finds grip, it reverts back to an open diff, which means you have to be ready to catch the snap-back. I can see why many of these cars are crashed in the wet with inexperienced drivers, as I pushed it a little hard on an out-lap and had a massive tank-slapper that I couldn't save (resulting in a full 360° spin). If the car hasn't over-rotated and you can keep the throttle completely buried, the slides are brilliantly balanced, it is just where you have to give a small amount of modulation, where it then comes off the boil and finds grip that is the issue with the standard diff. Either more power below 6000rpm or a plated diff might decrease the snappy nature of the car. Fortunately Bedford is an old airfield circuit so there is loads of room to play like this and try and learn how the car reacts.

Hope you enjoy the vids as much as I enjoyed the day .

Spins (going to fast on the first lap with cold tyres):

With passenger:

Cuts off abruptly at the end, because I ran out of space on the camera. Should have been more proactive in remembering to turn it off LOL:

Same Bedford track day from 25/02/17 (part of video 2 above), but this time from a different perspective - a friend following in his Seat Leon Super Copa (short-shifting like he is on a Sunday drive, as this is a full-on 300bhp race car from the one make series that used to support the BTCC, on race wets). You can see how much I am struggling for traction (with no torque what-so-ever), and the Seat is just gripping.

Mike RT4

At the end of March 2017 I installed an Axialflow quick-shifter linkage with the OEM shift knob and I can report as follows:

Positives:
The shift action is absolutely superb. Throw is much reduced (as you would expect) and it really makes the gear change even more positive and joyful than the standard set-up.

Negatives:
Because the shifter arrangement deletes the OEM harmonic damper built into the standard lever, there is some constant (low) back ground vibration resonance that is transferred through the lever as a low thrum that increases to a loud rattle from 8500rpm upwards. You can "feel" it in the standard lever (but not hear it, because the rubber damper isolates the noise transfer). As my UK facelift cars is fitted with the F20C engine, this somewhat spoils the forays up into the upper reaches of the rev range, so I am seeking a solution similar to the ones mentioned in the thread detailed below. However, to show just HOW good the shift is, if I can't eliminate it, I will just live with the noise.

For more info, see here:
https://www.s2ki.com/forums/s2000-mo...others-751849/

The Recaro ABE Pole Position in the car






This then brings us almost up to date, other than to say it also went on a 10 day / 3000mile jaunt to the South of Spain in August 2016, where it was absolutely faultless.

I have also finally managed to fit the passenger Recaro last weekend now thanks to Flanders, but will talk more about that when I remember to photos .

JamesD89

I really like how the car looks with the square AP2V1 setup.

And FYI, your car isn't missing any horsepower. Dynos measure power at the wheel while the manufacture figure is at the crankshaft. The wheel number will always be lower due to drive train losses. You would expect around 210whp from a car that makes around 240 at the crank

EDIT: I should read more closely

Mike RT4

Hi James,
If you read the thread as well as looked at the pictures, you would have seen that the figures on the graph ARE the calculated flywheel figures , I quoted the power at the wheels within the thread .

Pre-test pipe it was 182bhp @ the wheels, post test pipe it was 189bhp @ the wheels......

JamesD89

I should have looked at the dyno pictures more closely . That's really interesting, and a really low number.

Mike RT4

Like I said, this dyno is known for being soul-destroyingly accurate . Other S2000s (albeit with higher mileages) have fared much worse .

A dyno is just like a ruler, so as long as you use the same dyno each time for measuring, the improvements to the baseline figure are still relevant. I'm not interested in taking my car to different types of dynos to achieve larger numbers just to blow smoke up my arse .

noodels

What pads did you go for on the rear then, did you match front pagid RS29
dont know what to put on my rears ,have just put 2500 Ferodo on fronts with Oem honda front Discs.
Maybe Ferodo on rear also.
Are they needed for equal brake bias or can one get less expensive rear pads.
Am coming from ebc yellow on all 4 corners.
Ps I recognize that fat bloke in the passenger side
Edit: 2500 on the rear it is , 83 quid !

Mike RT4

At present the rear pads aren't anything special, just the hardest / cheapest compromise compound I could find, as I go through the rear pads at a ratio of 4:1.

The idea is to purchase a vented disc conversion at some point (something like the Urge kit), at which point I will get something better (I haven't even investigated if Pagid do RS29s for the rear yet).

With regard to Ferodo DS2500/EBC yellow, they're not up to track use in my experience, so for my application, I wouldn't use them.