Sunday, June 30, 2024

Lower car <=> improved aero dynamics. Time to step up the game.

So, the car has been lowered and it's on it's way to get a full racing engine. 
This means it's time to consider the aerodynamics.
By lowering the car, you'll accelerate the air passing under the car and that means suction to the road. Good stuff.
It also means an increase in turbulence and in this case, the lowering seems to have accentuated the rear a bit more than the front. 
I will be correcting this in the future with coilover adjustable, but until then, I need to increase front grip at speed, meaning that the air must be rushed-in and then allowed to exit before mid-car. 
First step: Lip-spoiler with a wing profile to accelerate air.
   
Splitter lip must allow air to run under and over it, but smoother under the car.  
 
So this is step 1, and it's completed :)

Step 2 will be a front end from the PowerHouse Amuse GT1 concept.
These front fenders and guild-type fins on the side skirts, are guaranteed to allow air to flow and make the front grip. 
Obviously it implied changing the wheels and although I log these ADVAN/ VOLKs and the 18" idea, I also love my genuine 5zigens... Still, one needs winter and summer tires, so I may just have an excuse there!
Stay tuned! More to come.

Saturday, June 29, 2024

9000rpm? why stop there?

The S2000 is the production car with highers MPS (mean piston speed). With 125BHP/liter, it was for years the highest specific power output car in the market (dethroned by the ferrari italia with 128bhp/liter). 
 
And although the F20C  was a development platform for Honda's glorious K-series engines, the fact that it went into the S2000 (a celebration car), allowed him a better designed valve train, FRM cylinder sleeves and a closer to F1 piston ans skirt design than any other production engine; making it what many consider to be the best 4cylinder engine ever built.
 
All of this is fantastic and i know several engines running strong after turboed to twice the power, and over 200.000km on the clock, truth be told that there beauties Rev very high, get abused quite a lot, and even with all the Honda iron-clad manufacturing quality, truth is that you should check your bearings and journals every 100.000km.
I mean, it's not a self destructing mechanism like the BMW high power gas engines, but it does deserve some caring, particularly if you race the car. 
 
As such, approaching 140.000km, even with Castrol's "titanium fluid" oils (claims to increase viscosity under pressure), my car is about to see it's bottom-end opened for maintenance purposes, and since we're touching it, why not replace the bearings and journals with some KING 3 metal ones!?
 
And since it's going to be all tight and new, and it's already lightened at the flywheel (and consequently in desperate need for a remap to adjust the idle), why not also UP the revs!?

It's one of those things most people don't really understand until they hit the track: you can have 600 NM on your diesel, but since you only have 4000 rpms to use before it disintegrates, you keep shifting! If you increase gear ratio you'll have a grip-to-drift uncontrollable thing on your hands. 
However, if you have a linear engine with low torque but very high power due to a very high rev, you can accelerate taking full potential of the engine and not need to shift gears between corners, and this is an advantage that most miss, until they see a comparison between the Honda Civic ep3 type-r and the S2000 on a twisting track... the simple 1000 rpm difference, allows for the s2000 to be faster than it's better balanced, i-vtec, evolution. 

So... Can I get more our of the s2000? 
Well ... so-so! 
The MeanPistonSpeed is a bit over 25Mts/second right on the sustained limits, but it's known that peaks of 27mts/s are possible with forged internals... Well the s2000 has forged internals form factory. As long as you don't make a living out of running the engine at 27mts/s MPS, it can handle it. 
The problem is the head. I mean it flows beautifully from factory, but valve floating will surely mean a catastrophic failure. 
There's something else, the engine cams design drops power after 8500 rpm. 

However, aftermarket has a solution and a bit of research has made me a buying list of goodies, and they've started to arrive. 

So Without further delay, where comes the list:
 
1st - FERREA 6000 racing hollow valves. Much lighter! Less inertia = less mass to control valve float and less energy loss. It includes valve guides.

 
2nd - Brian Crower Dual valves with higher grade and steel retainers and seats.
 
3rd - Now that we can push the valves further and for longer timings, time for Skunk2 Stage 2 cams. These immediately up the powerband by 700RPM.
 
 
4rth - The car does not have I-vtec, but you can unlock 10 to 15 bhp out of this engine if you tune it to supper high revs with advance... fully adjustable cam gears:
 

 5th - Adding to shit the head is going to be ported and golf-ball style bumps to provide perfect racing-level flow. We'll also be shimming the head to increase compression (like the JDM)

6th - Toda timing chain and Toda chain tensioner (already installed).
7th - Yet to be brought - LINK G4X ecu:
8th - Yet to be brought - ID4Motion s2000 digital cluster... more RPMS need a new cluster:
 
 
 9th- I'm very happy with the AEMV2 CAI and the mid-range it provides, but nothing makes engine response and mid-range like ITB's! Guess what just landed? OBX ITB's:






10th - yet to be brought- Cometic gasket and ARP head bolts 

11th - yet to be brought - King tri-metal bearing s and journal set + ARP rod bolts

12th - yet to be brought - J's racing exhaust header and a 70mm exhaust (yet to be chosen). 

13th - yet to be brought - Injectors... Factory will not fit the OBX fuel rail almost certainly

 14th - J's carbon air box and a custom made trumpet to airbox adapter.


As you can guess, the car will easily handle 9600rpm (short of 27mts/s MPS) and limit on 10.000rpm (at 28mts/s).

I'll be adding to this post as stuff arrives, and as the mechanic starts to work and send some pictures, I'll add to this article. 

Stay Tuned!

 


The s2000 handles beautifull as it comes from factory, no need to upgrade springs.... or do you?

 I've never really understood why people lowered their S2k.

As standard, the car is just a joy to drive and has a predictable behavior, corners fast, and is very controllable. 

So naturally I've never really understand the need to change the ride firmness and weight unless you do track and change the wheel profiles. 

That, of course, changed back in 2008, when I brought the 5Ziggens, and fitted some R888's to it. It' changed the offset of the car, widening it and dry grip increase was upped by a lot!

All the sudden, the car's limits got really high and there was an inherent pre-limit under-steer then I've never experienced before. It was easy to counteract with a steering blow, but it was a strange behavior I wasn't expecting. 

So... if those guy's altering the suspension on their S2k's had changed the offsets, that might just be the justification. 

So, evidently, I've recently fit a set of eibach Pro-kit lowering springs.These are stiffer and lower by 25mm. 

The result? Well the underlying on-limit under-steer is still there, but the limit's got all squeezed higher. 

The car corners faster, more stable, but it also brakes-off more violently. However the regaining of grip is also much faster. 

In the end, the fast responses where just tuned higher. 

It is a more frenetic car now and although I understand why Honda left this different as standard (and even so got a bunch of newbie drivers injured in phenomenal crashes), It makes more sense to have the car like this.

And I'll probably be pursuing coil-overs in the future to totally eliminate the under-steer approaching the limit. 

After all, people lowering their S2k where... absolutely right.

Wednesday, November 8, 2023

Old Horse, new brakes

If you follow this story, then you know my car has been running bigger, gripier tyres on bigger offset wheels.
It's also been running EBC Red stuff front and EBC green stuff rear.
As expected factory rotors started to show signs of the abuse under brakeing as you can depict by the colorful shades on the picture bellow.
yeah it's not been easy for the standard 300mm
SO...
...i'm now working on the new stopping upgrade.
Floating disks 330mm front and Floating disks 315mm rear
Rear retains the standard caliper but for the front ones i've just got hold of these:
some 9200's 4 piston (asymetrical area)  ready to bite.
They where yellow.. or red originaly, something I didn't want on my car, so Diogo Silva made this impecable paint job. If you are looking for a proper paintjob (with decalcs) Diogo is your man. You can reach him here: diogo2306silva@gmail.com
+351933590153

I'm now waiting on the reyland full floating grooved disks 315mm BBK for the rear end:
... and on my new reyland full floating grooved disks 330mm BBK for the front end:
The kit displayed here will not include the R calipers as, for 330 mm disks, the CP9200 are at capacity, but are lighter then the PRO R that can handle bigger diammeters.

... and some serious all round friction from EBC ( yellow stuff pads):
Kits includes mesh metal brake lines, so if the car used to stop on a dimme, it's gonna tear the road now :)

and it's Xmas .. the parts arrived. installing them soon.
Still to be continued... next year ;)

And continued :)
car got to the shop today and everything was installed:
and then front:
Brilliant job by Carmonauto lda, but the Reyland kit was a master-piece of a thing.
Everything fitted at first attempt, everything within dimentions and limits. 
Evidently, the rear shield had to be partially cut and the front one removed for good.

Driving Impressions:
Everything is still breaking in, so I didn't ready punish the thing. Having stated that, the car is much more balanced under braking. The tendency to dive the nose under braking, is reduced tremendously.
Everything seems more balanced and poised.
There is a lot less movement happening and that delays que rear comming out under braking.
As you progress que car seems to grip more and more, and finally start five the nose... the front calipers would obviously end up beating the rear ones and in dives the nose really late into braking line. But that gets linearly perceptible and only heavy braking.


Special thanks to:
Christian Lisboa - connections
Diogo Silva - Calipper painting and supply.

Wednesday, April 19, 2023

Engine vibrations... are... good!

Having a full racing clutch installed on your car, will get you into some charicat circumstances where you will need to either spin wheel, stall the car, or make a fool out of yourself by entering the harmonic stall-go-stall-go hickup mode.
Whenever you find yourself in hickup node, if your engine mounts are shot, you'll notice the engine ratling arround and that's bad.
So it's time to change'em.
Now why do engine-mounta go bad and then why call the article 'engine vibration is good'?
Engine mounts, on a road car, are made from rubber. There is steel screws surrounded by rubber, that screw the engine to the car chassis, but then, as any good rubber, introduce a jellow like effect, that aborbs engine vibration and restrains it from reaching the chassis, and consequently, your chair... and your ass as a direct consequence.
It's mostly about comfort... and you know how i think: Sophas are comfortable, cars are playstation like toys for men, so zero comfort, all fun and efficiency.

Consequently, after finding out that one of the engine mounts was bad, I brought this:
Now all i have to do is install'em and run the car. 
A LOT more vibration will be felt (good) but also sharper throtle response 
ww:re happy now :)

Thursday, March 23, 2023

Half-shaft Cv-joint vibrations, bump steer after offset changes or car lowering and MeganRacing solutions for you.

Anyone having an s2k for over 100.000km has been familiar with a strange vibration under acceleration that starts to become apparent as the car gains milleage.
This is due to the rear half-shaft cv joints hurting the cv joint bucket. 
This will become apparent if you run the car lower or with larger offler rimms, changing the geometry slightly... making it what!? 70% of s2k owners?! maybe more.

The solution is to change those parts... or you can just shift the buckets from left to right (you don't really worry about a small vibration while reversing... and add a cv shaft spacer like the one from megan racing.
The same goes for the bump-steer kit. Drive your s2000 lowered or with bigger offset wheels, and you'll find it very twitshy when it comes to road irregularities. Again, negan racingnhas a bump-steer fix kit that corrects the steering rack angles by adding 2 metal pieces underneath the setting rack mounts.

My car is not lowered but the 5Zigen Proracer GN+ weels are a huge offset difference that gets even more noticeable with the Toyo r888 tires.
So:
Evidently, more parts are in the mail... and soon the s2k will have even more inprovements to report.
Stay tuned.