Ongoing project thread of Sirion Rally 2 M101

[Granger]

With itchy feet I set to again tonight with a plan to get this all back together again.

I gathered my tools and things and carefully jacked the fuel tank up into position, attaching the fuel gauge plug, fuel return line and fuel feed lines before raising it high enough to put the 4 bolts in that hold it to the underside of the car. This is a better system than the bench press system employed on removal!

With the tank refitted I could then fit the new filler neck, I put a tiny smear of silicone grease on the inner edges of the fill and breather pipes and wiggled them onto the metal ends of the brand new filler neck, then wiggled the filler flap end into position with the gasket already fitted and did up the 2 brand new fine thread bolts that hold the top of the filler neck to the inner wing

from underneath I could then do up the 12mm bolt that holds the neck to the car, about mid-way along. This is the underside view

Then finally tightened up the hose clamp where the filler neck meets the rubber joiner for the tank, and the same for the breather hose and we’re done I think?

I gave the underside a few more squirts of dynax wax on a few spots I’d either missed, or hadn’t coated as well as I could have, then used a petrolly rag to wipe down the overspray on the exhaust and wheelarch lips. I also reattached the rear wheels so I think its all done now?

All I need to do now is lob a couple of gallons of petrol in from some jerry cans and then see if the car will start! I’ll drop it down off the lift tomorrow or over the weekend, get some fuel in it and then run it up and down the drive a few times to clean off the surface rust on the front discs from 2 months of inactivity. Then I need to book it in for an MOT!

[Granger]

MOT day today, results to follow - fingers and toes crossed though!

[evilhighway]

good luck

[Granger]

Well thats a good result!

The subframe bushes are the rear beam bushes which I am having the garage replace with the polyurethane ones I bought nearly a year ago, I didn’t fancy the job! They should be doing it this morning and will call me once done and the car is ready for pickup. Its taxed and insured so I look forward to driving it home later on and seeing the difference the PU bushes on the back end make.

I’m pretty pleased all in all - the exhaust blow advisory has gone, but it still wants dealing with. I’ll look to get a stainless custom 2" system made from downpipe back a bit later in the summer, it looks to be the thick end of £500 though so will need to save up my pocket money first.

[Rallynrace]

Congratulations on the MOT!

[Granger]

Got it back and taxed and insured it. The rear beam bushes were a pig of a job apparently, the rubbers came out, but the metal outers were VERY firmly attached to the rear beam voids and it needed a couple of hours of air chisel action to get them to part company.

So I’m very glad I farmed that particular job out!

Taken the car on some local runs over the weekend and its even better handling than before now its fully polybushed. The handling is not overly firm, but just right - and with the rear ARB its really grippy when you’re throwing it about.

A few more jobs have appeared, I need to get the AC regassed, the exhaust replaced a dashcam fitted and I’d like to look at the air intake.

On the final point, @Rallynrace - I think you mentioned you worked on a mushroom filter intake for the Rally2/4 models when new, do you have any more info? I was thinking of removing the factory airbox and intake gubbinz that sits on top of the rocker cover, replacing it from the enbow above the throttle body with a short length of aluminium pipe to the space behind the battery on the RHS of the engine bay. I think i will need to drill the pipe to fit the air intake temperature sensor that currently lives in the airbox, rearwards of the stock air filter. Then mount a cone/mushroom filter on the end of the pipe.

Would that work? Is that approx what you did?

[Rallynrace]

Hi, Sorry it’s taken so long to answer you. I was working in the Netherlands last week and came back with Covid!

For the production Rally 2/4 we used a straight replacement free flow foam filter in the original air box. We did test a cone filter at Milbrook Proving Grounds and it failed the drive by noise requirement for homologation.

The problem with positioning a cone filter by the battery, is that it is directly behind the radiator.

Give me a couple of days and I will get some photos of how I have set up the intake on the World Cup Rally car.

[Granger]

Thanks, and sorry to hear you’ve been ill!

I did some poking about and there isn’t much room anywhere else in the engine bay, but would be good to see the layout of your WRC one. My current plan was to locate the filter essentially behind the battery and run some straight pipe from the 90 degree elbow on the top of the throttle body across to it. Everything else seems to go over, or very close to hot engine!

I’d also prefer not to have the intake mounted low down if I can avoid it, yes the air is cooler (fractionally) but you risk the engine inhaling grit and water.

[Rallynrace]

Almost there, just the exhaust to finish!

Relocated the washer bottle to allow for filter.

Wrapped 4 into 1 Exhaust Manifold.

It now picks up the air from the same area as the OE filter, but hopefully cooler with no Cat in the engine bay, wrapped manifold and heat shield over rocker cover.

[Granger]

Thank you - yes I see the space that relocating the washer bottle frees up on that side. I’ll have a think/look and see whats what

[b_hoves]

What about something like THIS ?
You could put it in the same spot as the current airbox, and run the pipe to somewhere it’s getting cold air.

[Rallynrace]

Looks interesting.

[Granger]

Minor update here, got the AC regassed by a friend who is getting into mobile AC regassing as a side business. I’m pleased to say that 2 weeks later its still holding pressure and works as expected. The system only holds 380g of freon, but with a little cabin to cool its entirely effective.

In the recent heatwave its been quite nice, as the only car on the ‘fleet’ with working AC its been the go-to car!

The odometer has just ticked over 118k miles and its running well, though it does need topping up with oil if you use the top 30% of the rev range too much! Its still quite addictive, especially at traffic-light grands prix where its more than held its own against some bigger engined competition

It handles really well around twisty stuff too, the anti-roll bar on the back and the polybushes make it stiff, without being unpleasant to drive quickly. Bumps mid-corner can upset it a bit but never too seriously.

I need to sort out the exhaust still, as its not self-healed and is blowing quite a bit now. I’m hoping it’ll hold on for a bit longer if I try and keep it away from too much road salt and puddles and aim to get a new system put on over the winter.

Mostly I’m just enjoying driving it

[Granger]

Some more tinkering today in between work meetings, the last bits I ordered from AliExpress arrived and I replaced the stock air intake with a SPROTS arrangement

I retained the factory 90 degree elbow with the sensors and took the air box and resonator that sits on top of the cylinderhead off and unplugged the intake temp sensor, this all got put on the shelf in the garage so I can refit it for the next MOT or if I come to sell it, but replaced this with a cone filter and some 63mm aluminium pipe so the filter sits at the back of the engine bay between the fusebox and the wiper motor. While this isn’t a proper cold air intake, and a bit sub-optimal as its behind the radiator, there is a good updraft of air from behind the gearbox. With this engine/car there really isn’t a lot of options for placement of a cone filter, and I’m not entirely convinced that any areas of the engine bay are really significantly cooler than others. This is compounded by the fact that if you do locate the filter to a cooler area, you would almost certainly have to run the intake pipework over, or near to something hot which would then heat the cool air up anyway…

So for now, it will do.

I took the time to drill a 14mm hole in the aluminium pipe, fitted a 3/8" rubber grommet and a brand new intake temp sensor - leaving the original one in the air box of the intake gubbinz I removed - its just about visible on the firewall side of the pipework in the above pic.

Anyway, I started it up and at idle the noise is about the same, and crucially I’d done something right as no warning lights came on!

I took the car for a 8 miles drive to see how it was on the open road and was pleasantly surprised. No noticable increase in power over the stock system, but a really nice growl between 2500 - 4000rpm then howls as it comes on cam through to 7000rpm.

I’m really pleased with this, this setup is a fair bit lighter than the stock system and makes a nice noise with certainly no penalty to the power (and possibly a little bit more than standard).

With the price of fuel currently I’ve been using the Daihatsu quite a bit more, my other car is a 2001 Mercedes c-class with a 2 litre engine which is a fairly weedy engine on a heavy car and struggles to crack 32mpg most of the time on my commute to and from work. The daihatsu can be driven with gusto and still gives ~40mpg

Next up is the exhaust, which is combo with the air intake should make it quite a rorty little car, and round off the mild modifications to suspension and intake nicely.

[Granger]

Another thread on here led me to some other thoughts for mild modifications to the Sirion. Has anyone run semi-slick tyres and could anyone share any insight?

When I got the car a couple of years ago I opted to fit 4 brand new Toyo Proxes CF2 tyres - tyres I’d consider to be decent midrange. I’ve done about 2000 miles in the last 18 months and have been a bit underwhelmed by the tyres tbh.

In the wet its quite easy to have an inside tyre scrabbling for grip around a corner, and even in the dry its not that hard to have it jittering around. The roads around here are generally quite bad, with potholes and road repairs sitting proud of the road surface which probably doesn’t help matters.

I’d read good things about Nankang NS2R semi slick tyres and they are only about £80 a corner in the size I’d need. Has anyone run a Daihatsu on these tyres on the road who could comment?

I’m looking for better dry traction essentially. A had looked at LSDs but they are expensive, quite involved a job to fit and from what others have advised they can make the car a pain to drive day-to-day as it aggressively follows imperfections in the road surface and tramlines under acceleration

[Mr_Gormsby]

LSD may be expensive, but a good LSD will transform your car into something totally different to drive. Experience it and you’ll wonder why you didn’t do so earlier, that is when it comes to good handling. A really good LSD fwd setup can be a dog at low speed with a sense that the wheels are fighting each other. The clutch pack only needs a fraction of the breakaway torque of a rwd set up. For the road a viscous is the best. A torsion is better than nothing.

The N2SR is a good road tire. Go with the 180tw for the road. I’d use the N2SR in 120TW and Octopus Grip type softener as a “wet” instead of the AR1 which I’ve found not a great wet tire.

What are you spring rates? Front rate should be near std for road car 140lb prob for one of these, but 180-200lb for a rally car. The rear about three or four times the front. The soft end gets the grip. But I may be preaching what you already know.

[Granger]

on to the more mudane, I hav an ongoing issue with a wobbling steering wheel above 60mph, like a wheel is out of balance. The front wheels have been balanced twice to no avail, and checked for buckled-ness as well.

It was suggested that it could be a couple of other things, firstly a sticky caliper. Seemed possible, and as I had the required tools and bits to do so I decided to remove and grease the caliper sliders tonight. The passenger side was fine, both sliders came undone fine and were indeed quite dry so i greased them with silicone grease as per. I moved on to the drivers side, the top slider came out reluctantly, needing the caliper prying away from the hub ever so slightly to get it to release, and was also dry so got lubed. The driver side bottom slider was having none of it and rounded off completely, the little tinker (to spare the innocent, I shall not repeat the actual words used when this happened)…

So thats thats on the lift for another week then. My brother is posting me some “so you want to be like that do you?” Irwin bolt extractors, and I ordered a slider kit including new slider pins, boots, silicone grease and the nubby thing for the barbed slider, all of which will take a good few days to arrive, frustratingly.

If this doesn’t solve the wheel wobble, it may be escalated to DEFCON 3 which is a potentially bent or unbalanced driveshaft. I have replaced one with a secondhand unit which might be a duffer, I have managed to reassemble the original one now so if it comes to it I’ll need to swap that back over and refill the gearbox oil again…

[Blyatsu]

Ah yes, sounds like one of those days. Quite annoying indeed. I’m never sure whether or not it’s a cause for a wobbling steering wheel, but maybe check the tie rod, LCA bearing, steering rack etc. for any play.
To be completely honest, I’ve never had a Dai without a vibrating steering wheel at 60/70 mph, I always assumed that was part of the car, but never looked into it more. The Blyatsu got new LCA’s, tie rods and any bush imaginable replaced plus it runs on BC coilovers and still has some vibration. I’m curious to know what it could be, and if it could really be an axle

[Granger]

Yes, definitely one of those ‘maybe I should have stayed inside and drunk beer’ sort of evenings! Oh well!

interesting re the wobbly steering wheel being a ‘feature’ of Daihatsu’s generally though, maybe I’m chasing this in vain? I suspect the light weight of the cars doesn’t help, where bigger cars with a slight imbalance would dampen the vibration because of the mass to absorb it.

I’ll put it all back together next week when all the bits arrive and take it for a run to see what its like, its really only an issue on motorways where you have sustained 60-80mph and straight road, I don’t notice it on the A and B roads (single carriageways, mix of 30, 40, 50 and 60mph limits, generally more twisty) round here, but my drive to work is about 60% motorway and its a bit annoying.

I’ll keep on at it, it must be something thats fixable, surely they didn’t come out the factory like this?!

[Blyatsu]

I wouldn’t know, but sometimes when I look at the suspension I wonder how it doesn’t fall apart at all. To think I drove 185 km/h the other day . Wouldn’t be surprised if the rubber bushings are too soft and allow a bit of flex in all the components, or that it has some influence