My Sirion M101


hi guys!

First, I have been ungrateful… :disappointed_relieved: the truth is that the end of the year was overloaded with work so it was rather little that i was present.

first, I’m going to thanks to @Mr_Gormsby for sending the wing. The truth i was some fear that some poisonous snake egg would come hidden in the package but all good :stuck_out_tongue: Very happy and very grateful for the good disposition!

Thanks for the message!!! :hugs::hugs::hugs::hugs:

Well, the truth is this report is focuses on the last race of the year, there is not much more except we take the little Sirion to the dynamometer.

Our last race was very funny, again we won the category so we ended the year with 3 of 10 wins (not bad for the first time I participate in a competition).

There is a issue to improve, the car brakes durability is very little, both in the race in November and in December I was left without brakes in the middle of the race (thank goodness that i take replacement pads). It may be that as the car goes on faster, the brakes are not lasting very long.

Here I leave some photos of the race (with my new wings :grin:)

Finally we took the car to the dynamometer. We do not install the Ecumaster but an Apexi SAFC2. We put the ecumanter in a nissan B15 to release the limiter rev (now rev up to 7500 rpm), now we clear that it would serve perfectly to release the rev limit of sirion.

Well with everything the car has today we mark, after setting, 113 hp to the engine (100 hp to the wheel), I really expected more but still a good number for a 1.3 engine. In the trial and error we achieved 102 hp to the wheel but decided to leave the engine a little more protected due to the pistons of high compression, the AFR stayed at 12.8 full gas. (in 13.0 it has 2 more hp).

Well, that’s all for now. The next race (and first of 2019) is this January 12 and 13 at 700 km from Santiago. I’ll tell you how it was in another post

Thanks for reading me!


interesting - so malaysian pistons + header + safc gave you approx 5hp increase
was it knocking at that afr?
Curious as to why you had it running so rich and why that was told to be keeping it safe?
guessing that was with low octane unleaded?

if you don’t mind sharing - what was the weight of spring you ended up being happy with?


Excellent. Love the pics. I do believe a disc rear will help a bit. Do you have the Daihatsu Applause with rear disc over there? That would be an easy conversion for you. Then bigger front disc.


Looks quite balanced. Some more neg camber though.


Congrats on another win! To go along with MrGs suggestion on adding rear discs I would change the Front brakes for some ones off a Copen. If you remove the brake dust cover thing the calipers bolt right up and discs slide straight on. This serves a duel advantage of increase disc size and better options regarding high performance pads that are available for the copens.


@Mr_Gormsby, @b_hoves… yes, I could try to get an applause rear axle but very few units were sold in Chile, I would have trouble getting spare brake discs (not unlike trying to get from Sirion). More than ever I look, until today without luck.

Regarding the front brakes, neither the copen nor the YRV Turbo were sold so it would have to be an adaptation of another brand like toyota. :disappointed_relieved: I will continue to investigate and soon I will bring novelties…

@Patrick_Hart Finally the spring are the original ahead and 50% harder back together with wedges. The shock absorbers are KYB Excel. Camber set in -2 for this race due to a problem with the adjustment bolts, the next one I hope to have -3 again (Visually it seems that it had less but in the tire the wear is noticeable).

Regarding the tests on the dynamometer, the first run got 98 hp to the engine (in stock theory it should have 102). only with 97 octane fuel (RON) the best number we got was 110 hp. When using 97 with an octane booster we jump to 115 hp. (This is the booster we use VP Octanium)

The issue is that the knock sensor marked up to 190 knocks with the afr in 13.0. With tha AFR in 12.8 we lost 2 hp but the knocks dropped to 110 maximum (40-60 average)

A curious fact is that with the original electronic the AFR goes between 11.9-12.0 full gas… very rich and that’s why it lost power.


I’d agree there on sticking with adapting brakes from something local. You may not need a rear disc that goes onto the stub axle. You have a lathe so you can machine the drum part off you Sirion rear brakes leaving the hub and the OD can be machined down to match a disc that just slips over. I machined Charade drums down to put the Applause hats over top. Check out Mazda MX5 (early versions at least) rear discs which are 100pcd and saves redrilling. Also some MX5 rear calipers are virtually identical to Applause. I think they have a 1mm or so bigger wheel cylinder bore which is not a bad thing. Of course adapt anything but these work, are about the right size for the master cylinder and have a mechanical handbrake.


Yaris brakes might fit (I have no idea if they are bigger), as the first gen Yaris and the Sirion were basically the same car.


i get so confused with the concept of improving rear braking
do you guys not bias towards the front unless in wet?

and i’ve been playing around with copen onversion on my mira and i can’t say i’ve been impressed [perhaps i should have a build thread but i’m too lazy/unmotivated/without time] and found a lot more interest around better compounds of pad than disc/etc swaps for rare items [and frankly the copen stuff is pricey!?]

although I’m looking to be braking from high speeds . … in gymkhana type stuff maybe just a quick grab of brakes is better? therefore large everyhing is better?

or all options just different rather than better?

but also - did i miss the mention that you were running out of brakes?

also have you noticed any fuel/oil surge? a few rally guys i’ve spoken to have found this a lot. i haven’t yet in either the sirion or the mira :thinking:


Generally I have found the dais I have worked on to be under braked to the rear. Meaning std the front is biased anyway and any front improvement worsens the situation. If the Copen items have not resulted in an improvement something is wrong. Bigger caliper piston with small master cylinder will give less effort and better modulation. Bigger rotor better leverage and more cooling. Here is the thing I hate on Miras, the stupid diagonal split of the master cylinder for safety and two brake lines to the rear. I have a single to the rear with cockpit adjustable bias valve instead of the under bonnet one and then a hydro handbrake. Better compounds if you are going to get them hot and same for better brake fluids. Pads gone? Hard pedal and no brakes due to gas coming off the pads and hovercrafting over the disc. Boiled fluid? Gas in the brake line compresses and pistons don’t move enough to get the pad on the disc with force, so spongy pedal to the floor. Two laps max of a track like Lakeside and a std pad and set up will cook them. Bigger should let you brake latter but will still fade. My good pads are $400au a pair wholesale. Next thing to install in mine is a pedal box with balance bar, Brembos from a Renault and a tire with 205 width and 80tw. Sorry for the ramble.


i’ve always gone for all front bias anyway
never seen logic to have rear braking except sometimes in the wet
especially if you have good weight jacking - all you’re going to do is lock the rears almost straight away with very little weight over the rear

not sure what you mean about a rearward line being better as a single

the rest of what you were saying made no sense :stuck_out_tongue: so i won’t reply to anything else :stuck_out_tongue:


I haven’t had that much experience, but:

At Mallala I had stock front rotors (D-sport ones didn’t come in time), Project U N+ Racing pads, stock rear drums and unknown drum pads in rear. Tyres were 195 wide 15" kumho V720’s.

At no point could I brake as late as my mates Proton Satria gti with arguably less track orientated pads, similar tyres though.

I’ve since got the D-sport brake discs in the stock Sirion sizing.

All of that may have been a ‘waste’, however my thoughts were similar:

  • keep weight down
  • it’s a light car
  • rears don’t do much work

Despite the GTVi’s performance gain, if the braking is still relatively pedestrian, the size/type may be just mismatched for track work. The increase in size to copen, whilst not huge on paper, is likely significant in a low weight car. Additionally the cooling from rear discs and not drums will improve the whole systems performance.

Advice from Gormsby and others is routinely: Copen Front / Rear Disc. Given the main braking points of that Proton are; larger discs and rear discs - it is likely a better option than any weight saving of smaller units. IE the time on the track gained from shortening the braking distance is much greater than any time gained through keeping weight down.

Since i’ve got these discs - i’ll probably head out once more with this setup to see if the fronts are better. Or leave the fronts the ‘small’ sirion units and convert rears to disc, before going copen fronts.

my 2c from limited running on the track


I have only done one track event in a Sirion and for the first half of the event was just learning the track and the car (at it’s limits). At the time I had slotted rotors, Ferodo race pads and dot 4 fluid. I had no issues with brake fade and was stomping on the brakes pretty hard in the last 2 sessions. I was keen to get some more braking power and the plan was for braided lines, copen rotors and calipers, d-sport race pads and dot 4 fluid.
I think there was someone on this forum that was making adapters to fit Honda prelude brakes to Sirions. Might be worth investing.
EDIT: Search for Compact Motorsport ltd on facebook. Tim, the owner, was planning on CNCing the adapters.


If wanting full front bias then you can’t be maximising braking effectiveness.

I gather you are not a left foot braker. Left foot braking can help balance the car through the corners and kill understeer.

Single line to the rear makes it easy to add the bias valve and hydro handbrake. Price a group N bias valve which is twin in or a hydro brake with twin in. Installed the two items would run $2000 as posed to $200 for a single line. And you still have to change the double lines since the braking crosses over diagnally from the master cyclinder chamers (front chamber brakes, say, LH front and RH rear and rear chamber opposite).

Even if the rear only has the capacity to do 10% braking then why have it doing 5%.

I can adjust on the fly and would have more rear bias than most. My rear discs are fairly big and need to be fade worthy due to left foot braking. In competition mid corner I am braking left foot and bringing power on hard. Not for everyone, however, for me it has bought podium results in comp at state level.


so much lol
yes i can left foot brake
but not applicable
obviously if i want national titles we all need massive rear brake conversions then!
you’ve all been told here first! :laughing:


Not “can you”, “do you”? I left foot brake all the time. All cars I own have a brake pedal wide enough for both feet to do a little dance when coming to a full stop. I don’t think it would be a good thing to only left foot brake on the day of the “nationals”. Certainly not for everyone and I don’t think it necessary for you or 99.9%. Just what I started doing back in 1978 when dad let me drive the vw or esp the mini on the 10acres up the back when I was 10. It was the only way to make the mini fast.


Hi guys,

I love this kind of discussions, I learn a lot from them. :hugs::hugs::hugs:

I just wanted to tell you that I’m sad, after two days of track, I finally broke the little Sirion’s gearbox… The third gear broke in thousands of bits…:sob::sob::sob:

Anyway it was in the final race and despite the broke we got second place in the category.

later I will post more details …


Sad to hear about your gearbox. They seem to be a weak link for most Dais.


Hi guys,

As we already told you, we finished second in the category on the weekend, however, the gearbox happened to a better life.

However I’m happy with the performance of the car.

An issue that I forgot, i had change the brand of brake pads and these if they lasted the two days of competition, is an improvement :grinning:

Here I leave a video and some photos taken at the event.


not really on circuit. balancing corners a little in the wet sometimes
but i fail to see the gain and i need my left foot for clutch
but in your gymkhana stuff totally see the gain