building a dedicated track car
 

Hi guys.
Im turning my scoob into a dedicated fun track car.
I have bought a 5 speed gear box which was refurbished by Api 6 k miles ago. Just wondering what the situation with how often oil changes with a newly refurbished box should be and what oils people recommended for box and diff for track use. Which weight and brands please? Im running 330bhp and 300 torque in a bugeye. I know this is not an ideal amount of power to run through a 5 speed on a track but im thinking that the box is fresh so should hopefully handle it if treated with respect.

Im hearing differing opinions on which engine oil to use also so any info regarding all appropriate performance fluids to use on track would be awesome please.

Im also fitting the following parts to begin with then hopefully getting out and having some fun. Would anyone advise brands of these parts to use or suggest any extra bits to fit?

Thanks in advance to the Scooby gurus!

Roll cage with harness bar
Harnesses
Magnetic sump plug
Bigger radiator
STI topmount and undertray.
Braided brake lines
decent pads. maybe blue stuff
Strip interior.
Slick tyres and spare wheels
Cold air intake from front bumper
Ducting aimed at brake calipers
Set of gauges
Boost controller possibly?
Exhaust noise reduction possibly? How can I test if this will pass track regs?
Adjustable rear arb– whiteline
Adjustable front arb – possibly?
Anti lift kit?
Fuel cut off
Battery cut off
Geometry set up with camber bolts
Powerflex black bushes possibly?
Baffled sump plate RCM
Front upper strut brace
front lower H Strut brace
Rear strut brace
External pump 50
Tow eye
Hks oil filter
Performance fuel filter possibly?



Any advise would be much appreciated

Many thanks.

gearbox is gonna go, 5 speed wont cope with 300ftlb on track. Dont even bother with a boost controller, will need proper map and decent ecu that will pull it back if something not right

add the following

Thermostatic controled oil cooler
Syvecs ecu
front mount


Exhaust wise cobra do a track friendly one ;)

I've ran 390 bhp on my blob wrx on several track days and 20k road miles, with no signs of the box giving up. Some boxes last longer than others, of course, but driven with mechanical sympathy you might be suprised by the longevity.

My point is this, a 5 speed box is cheap as chips, and it will not magically self destruct immediately. You're going to have to wreck a bunch of 5 speed boxes before you're at the cost of one six speed box, which also isn't bomb proof (e.g. synchros etc etc on older boxes).


Oil-wise, I've used comma racing oil for track days, and comma fully synth 5-40w for the road (changed about every 4k (more due to time than mileage mostly)).


Having said that, if you haven't started the track conversion yet, I'd think seriously of what you want out of the car. The subaru is a HEAVY lump to drag around corners, and it makes everything expensive (tyres, brakes, fuel, wheel bearings etc etc).

If you want something quick and nimble, look into lighter cars (I say that as someone who's got a track project impreza mid way completed, but I've unfortunately been in my friends Caterham R400, and there's no way the scooby will be as quick, and he spends 100 quid on average on fuel and tyres / brakes / servicing, where-as my average is about 300 per day, if nothing big needs replacing).

oh, also, slicks need completely different geometry and suspension to normal road tyres, so I'd stick with track day tyres (or indeed normal road tyres for the first couple of days), until you have uprated the suspension (and made it so horrid that it's completely unusable on the road ;) )

I haven't seen what mods you've done already, so apologies if I'm telling you how to suck eggs.
I'd also look at a couple of mods that may help the longevity.
An inlet manifold thermal spacer is a pain to fit, but will help reduce intake temps and may help preserve the life of the drivers side pistons. An header tank spacer kit does a similar, if less effective job, but at a fraction of the difficulty and cost. I fitted a rallytech one that cost £17.50.
An oil catch can or oil/air separator will help prevent the inside of your intercooler getting a coating of oil after a day of heavy boost (return to sump would probably be advisable). It'll also mean your engine won't have to burn the oil off.
Brake stoppers are also a decent way of sharpening the brakes for not very much cash (£50 ish) . On mine it had a similar effect to braided hoses. As well as the pads I'd look at the discs and fluid as I've found the standard set up does fade surprisingly quickly under spirited conditions.
If you're looking at anti lift kits, springs and bushings then a roll center kit may also be an idea, depending on if (or how much) you're looking to lower the car.

More important than any of that is a trailer. You will break it.

Tidgy, the guy doesn't need a syvecs for an essentially standard car. An alcatek will do more than he ever needs for a fraction of the cost.

alcatek isnt as capable as a syvecs and will be worth more than a brand new alcatek even second hand ;)

Also not to mention LC and AL are cost options on a alcatek ;)

If the engine trips are available on an alcatek then I would go for it but if not then the syvecs makes sense for a dedicated track car

Thanks for all the input guys. Much appreciated as modding for track is totally new to me. I have looked for a oil cooler but i can't find one for an impreza online? Does anyone have a brand/ supplier to recommend? And how much work is it to fit one?

I have a prodrive ecu. Will this not be sufficient or can it be mapped to include the engine trips* that the others mentioned have?


The comma racing oil sounds good. I have seen people recommend 10 - 50w for track before but cant find that consistency in their range. Which did you use?

I didn't realise you had to change the Geometry for slicks. Maybe ill stick to track tyres for now. Anyone recommend a brand? Ive used eagle f1s for fast road use which were fantastic. Not sure how they would cope on a track though.

The header tank spacer sounds like a great little mod. Struggling to find a uk or europe supplier for those. I can only find usa or thailand with a 10+ day turn around.

I've seen d1 oil catch cans cheap. Would they be any good?

I will buy the tigwa brake stopper i think. Sounds good and probably Motul RBF600 fluid.

Again, any info is massively appreciated.

Yes it has closed loop knock correction etc.

Tidgy the guy isn't talking about a 20k build. A second hand alcatek would suit his needs fine. And track days won't need Al or LC anyway. So kind of a pointless exercise

The Tegiwa stopper is a good one and easy to fit. For a catch can you need a three port version, preferably baffled. Obp do some good ones, but they are about £80, I've just ordered one from ellis fabrication that was a bit cheaper (£50). I'm hoping to fit it this weekend so I'll let you know how I get on. This is a very good install guide.

https://www.scoobynet.com/general-te...mp-return.html

Also to consider would be subframe locking bolts and a rear diff brace. I'm not sure I'd recommend those for a daily drive due to the increase in NVH, but they're well suited for track.
Ps. My header tank spacer kit also came from Thailand, but took less than a week to get here.

Also, rumour had it that gearbox reinforcing plates can help protect your gearbox against a premature end.

https://www.scoobynet.com/subaru-par...ng-plates.html

I haven't read around the subject enough to be sure but it might be worth investigating.

What you do to the car will depend on budget and what you intend doing with it. If you intend using it as a daily driver and fun track day car then what you do will be simpler if you intend using it to do competative sprints that's another ball game altogether.

If you intend using the car for track days only I wouldn't bother with a cage it will limit the cars use as a road car. If you intend using it for competative sprints then again it all depends what class you run in. If you intend to run in road car class you do not need a cage. If you decide to go down the cage route then again it depends on how serious u want to get.
These would be my recommendations. You can get a cage made to your specs but but be careful to ensure you can get MSA certification for it, if you can't you could have issues if you look to compete seriously. I have the Q023 which is an excellent cage and all these are MSA certified.

Suspension is where you need to look at seriously but again depends on car use. My advice is buy the best you can afford first time or you will end up changing it. If you are going to be using the car seriously forget the likes of BC's or other budget brand coilovers, they are decent enough for road use etc but on track they just are not up too it.
The easy mods would include Whiteline front and rear roll bars, drop links, adjustable rear arms, anti-lift kit, roll centre kit and steering rack bushes and a good geometry set up.
In terms of bushes I would strongly suggest fitting the Whiteline bushes they are far superior to the likes of powerflex etc. I had powerflex bushes and replaced them all with Whiteline bushes.

If you retain the standard ECU I would strongly suggest fitting an Apexi AVCR to control the boost.
If you keep the standard ignition switch and run in road car classes you do not need a fuel/battery cut out switch all you need is a sticker next to the ignition switch.

While slicks are good there are some terrible ones and some good ones, tyres are critical and will depend on whether your competing or just doing track days. Slicks will be no use if it rains so you would need to consider if you have the budget and space to take a set of slicks, wets and a set to drive home with or go with something in between.

Brakes and pads are important and the likes of blue stuff pads are just useless. If it's a track only car there are far better pads out there but they are not cheap but cutting corners here would be madness. Alyn at AS Performance would be the man to get advice from and too supply. One of the best pads for road use and occaisional track use Is the PF Z rated compound.

Bigger radiator can be a good idea but a good condition standard radiator is efficient and works well the only issue is the end tanks are prone to leaking as they age.

If you fit a proper baffled sump then the RCM sump plate isn't really necessary. You will get far more protection from a proper baffled sump than the sump plate.

Thanks for the info. That gives me a bit of confidence knowing 5 speeds can cope with 390bhp on track. The gearbox was reconditioned by api 6k miles ago so in good shape and i plan on treating it with respect. Ive decided on the scoob as my track car for sure. I know the car, how it performs and how it has been treated. I looked into an mx5 for a while but if i got one i would still want to spend around 4k on getting a decent one and setting it up right.

This is the first i have heard about a completely different set up being required for slicks. I have some bc br coilovers. How would the Geometry differ to that of normal track tyres?

Thanks for the info. Ive decided to get the header tank spacer kit, oil catch can from ellis, havent decided on setting it up as return to sump or not yet. Not sure what the advantages would be to return it.
Got the brake stopper too so that will be getting fitted with front brembos and braided lines and decent fluid.

Righto. So the cheapest option would be the second hand alcatek then. Im tempted by the AL and LC but i think the 5 speed may explode!

Thanks for all the info.
I have a daily driver so the scoob will be a dedicated track car. Im not looking to do serious competition racing at this point just fun track days.

Im looking at getting a cage for a safety point of view but not something i essentially need to begin with.

Ive got bc br coilovers as these got good reviews for a set up less than 1k which was my budget.

On the front Ive got whiteline front arb, drop links, alk, s.r bushes, strut brace, h brace. On the rear ive got cdf rear arb, drop links, camber bolts, rear strut brace. Not sure about the adjustable rear arms or roll centre kit yet.

Ive got an apex avcr boost controller so now i just need to set it up how i want. How would you recommend to set this up? I was thinking of slowly increasing the boost from 1st gear 70 percent, 2nd gear 80 percent and 3rd onwards 100 percent but within safe zones.

I have seen a set of used yokohama slicks i was considering buying. Does anyone have experience with these? I would probably get something like these and some r888s then maybe a set of wets as the car will be going to track and back on a trailer.

I will be fitting brembo fronts so im hoping to find a used set with decent discs. The pads can be track use rather than road.

I also got a big radiator and rcm baffle plate.
Ive got a mocal oil cooler but decided not to fit it yet and see what oil temps i get first as ive heard the standard modiene is good.
Cheers again guys. Much appreciated

I run a track car.

A few thoughts off the top of my head....

Cage - I prefer one that runs through the dash as opposed to a dash dodger.
I have a dash dodger in at the moment.

If you get a cage make sure you have harnesses as well. Try not to mount the harnesses on the floor but off the cage or a harness bar at just below shoulder height.

Engine oil - Best I have used is Silverline Synionic
Gearbox oil - Redline shockproof

Tyres - Best value, road legal and good grip once worn and hot are Federal RSR
I would go for two sets of wheels. One being the wet set and one being the dry set. Slicks are way better than anything else...but they are not so progressive as RSRs at the limit. 888s are a bit better than the RSRs but are pricey and are not as hard wearing.

Brakes are very important, whatever set you run spend a fair bit of money on the pads, do not cut corners.
I would go for a high end Pagid or Performance Friction pad.

I would strip the whole interior out, put the cage, harnesses in and two race seats.
Then that is the basics of the inside done. And you can add extinguishers, firewall and anything else at a later date.

Stick in an oil pressure and oil temp gauge in at a minimum, which it looks like you are doing, So you can see what is going on, try and get ones with some kind of audible warning. As when you are on track often you do not have time to look at the guages.

Agree. Given the choice money no object starting from scratch.... I would go for Syvecs.
But I have been running a Simtek/Alcatek with the closed loop idle and knock correction enabled and it is more than up to the job

My thoughts would be to sell what you have and buy a car which has already had all the hard work done to it you will save a fortune in the long run and time

There some valid arguments for this route as long as you know the work has been done to a high standard and you know the parts are all in good condition.

Agree with you on that one Archie

Thanks for all the input guys. Im enjoying buying the exact parts i like and building it just how i want
Just looking at the boost controller set up and wondering if anyone else has advise on how to set this up. Arch mentioned using one instead of upgrading the ecu. Any thoughts?

Cheers

Unless you have an ECU that can run multiple maps like a Syvecs you will find the ability to change your boost setting depending on the track conditions invaluable.