New 9n3 GTI owner

[triode12]

Hi,

I just purchased a 2007 Polo GTI as a track car and run about. I was wondering which performance upgrades are recommended if I want to track the car?

I know an engine tune and coilovers are par for the course (I have already put on stiffer sway bars from WhiteLine and a BMC performance filter).

Is upgrading the cat back exhaust necessary? or can I get away with just upgrading the down pipe and putting in an FMIC if I want to go to Stg 2?

Is the upgrading to a PD160 worth it? They seem to be selling at ridiculous prices on Ebay - $376 from Darksidedevelopment's Ebay store.

I don't want to spend money on upgrades that are not necessary or don't provide a "good bang for my buck" while still making it street legal.

Thanks in advance for any advice.

[simon k]

I bought my polo for the same reason, daily driver and track, same with Sam, though I haven't gone as far as he has.. have a look through both of our threads and you'll see what we've done (I'm not much good at keeping mine up to date though). I'm on a tight budget so almost everything has been done as cheaply as I could, doing all the work myself. The only things I spent proper money on were the SEAT intercooler (though it was new 2nd hand), wavetrac diff (new 2nd hand again) and bilstein dampers (which I converted to coilover at the front).

I'm running stage 2 with FMIC and dump only and it's good, though the tune is generic and I'm sure there are areas where it doesn't perform as well as it could. I'm looking to rectify that soon.

Exhaust wise, I made a 3" dump out of scrap stainless that goes into a 100 cell cat and then to the stock exhaust, but I replaced the stock muffler with a little straight through muffler. Its not much louder than stock... So I say no, catback isn't needed. I think Sam's exhaust set up is much the same as mine.

Intake wise I didn't think pd160 was worth it, I got some PVC plumbing pipe from bunnings and shaped it with a heat gun to fit between the slam panel and radiator. I removed the stock intake parts completely and cut a big hole in the air filter box. I've recently replaced the PVC pipe with more scrap stainless, using stubby holders to keep it in place and stop it from rubbing on things it shouldn't. The only thing with the intake though is that the air cleaner (I have a BMC filter too) was full of bugs when I had it out to do the gearbox, so they need to be checked regularly.

[h100vw]

LCA bushes are rubbish in stock form. Recommend Superpro or other caster correction versions. Find my build thread. Gavin's cheapy GTI.

[simon k]

Yeah, I put those in, bought them when they were on special at sparesbox.

I also put in Audi TT ball joints for more camber and made eccentric inserts for the subframes. Every little bit of adjustment you put into the front end adds up..

[triode12]

I bought my polo for the same reason, daily driver and track, same with Sam, though I haven't gone as far as he has.. have a look through both of our threads and you'll see what we've done (I'm not much good at keeping mine up to date though). I'm on a tight budget so almost everything has been done as cheaply as I could, doing all the work myself. The only things I spent proper money on were the SEAT intercooler (though it was new 2nd hand), wavetrac diff (new 2nd hand again) and bilstein dampers (which I converted to coilover at the front).

I'm running stage 2 with FMIC and dump only and it's good, though the tune is generic and I'm sure there are areas where it doesn't perform as well as it could. I'm looking to rectify that soon.

Exhaust wise, I made a 3" dump out of scrap stainless that goes into a 100 cell cat and then to the stock exhaust, but I replaced the stock muffler with a little straight through muffler. Its not much louder than stock... So I say no, catback isn't needed. I think Sam's exhaust set up is much the same as mine.

Intake wise I didn't think pd160 was worth it, I got some PVC plumbing pipe from bunnings and shaped it with a heat gun to fit between the slam panel and radiator. I removed the stock intake parts completely and cut a big hole in the air filter box. I've recently replaced the PVC pipe with more scrap stainless, using stubby holders to keep it in place and stop it from rubbing on things it shouldn't. The only thing with the intake though is that the air cleaner (I have a BMC filter too) was full of bugs when I had it out to do the gearbox, so they need to be checked regularly.

Thanks for replying and for the information Simon. Would you happen to know the diameter of the piping to the original muffler?

[triode12]

LCA bushes are rubbish in stock form. Recommend Superpro or other caster correction versions. Find my build thread. Gavin's cheapy GTI.

Thanks Gav. I will.

[triode12]

Yeah, I put those in, bought them when they were on special at sparesbox.

I also put in Audi TT ball joints for more camber and made eccentric inserts for the subframes. Every little bit of adjustment you put into the front end adds up..

Were these the LCA bushes you bought Simon? SuperPro Front Control Arm Lower-Inner Rear Bush Kit Fits Vw SPF3271-95K | Sparesbox

[simon k]

Were these the LCA bushes you bought Simon? SuperPro Front Control Arm Lower-Inner Rear Bush Kit Fits Vw SPF3271-95K | Sparesbox

no... that one would be too expensive for me, this is what I bought. You're in luck too, they're on special today

SuperPro Front Control Arm Lower-Inner Rear Anti Lift Bush Kit Fits VW SPF3273-80K	9995-SPF3273-80K	1	$114.70
SuperPro Front Control Arm Lower-Inner Front Bush Kit Fits Seat Skoda VW SPF3311K	9995-SPF3311K	1	$73.90

and the dogbone

Superpro Engine Steady Mount Bush Kit SPF2907-70K

9995-SPF2907-70K

1

$80.95

the exhaust is 53mm ID / 57mm OD which I guess makes it 2.25"

[triode12]

no... that one would be too expensive for me, this is what I bought. You're in luck too, they're on special today

SuperPro Front Control Arm Lower-Inner Rear Anti Lift Bush Kit Fits VW SPF3273-80K	9995-SPF3273-80K	1	$114.70
SuperPro Front Control Arm Lower-Inner Front Bush Kit Fits Seat Skoda VW SPF3311K	9995-SPF3311K	1	$73.90

and the dogbone

Superpro Engine Steady Mount Bush Kit SPF2907-70K

9995-SPF2907-70K

1

$80.95

the exhaust is 53mm ID / 57mm OD which I guess makes it 2.25"

Thanks for that! Getting them now.
Would the 80K Dog Bone Engine mount be better or too harsh? Or is the 70K enough wrt to stiffness?

[simon k]

Thanks for that! Getting them now.
Would the 80K Dog Bone Engine mount be better or too harsh? Or is the 70K enough wrt to stiffness?

dunno sorry, I've only had the one type, I went with what I found searching on here

[sambb]

If you want to dotrack stuff then I'd go for the chassis mods first. You'll have more fun with agood handling car and a good handling car on good tyres is way quicker than astock chassis Polo with 300hp. The OEM brakes are actually fine at firstprovided you have decent pads and fluid so you'll be good there initially.
The cars intrinsicshortcomings are that it has woeful bushes, terrible geometry and terribledamping. Bushings – just change them all. Geometry - you have insufficientfront caster and nearly no front neg camber and the front ride height needs tobe kept high if you don’t like positive camber through corners. At the rear ithas a workable amount of rear camber but the toe is out to lunch.

If I was to have mytime again, and assuming that you’ll do suspension in a staged sort of way sothat each step doesn’t redo a previous one (the most budget conscious way) thenI’d do it like this:

1. Rebush thewhole car including dogbone and rear beam. Get the rear LCA bushes that areoffset and set them in the max caster position. You already have anti roll barsso set them on soft at the front and hard at the back. Then get a set ofSpeciality Products/Eibach shims to shim the rear beams stub axles and correctfor its near 8mm toe in. No FWD car will hook into a corner with that much toein so shim it for 2mm toe out and maybe a touch of additional extra neg camberand right there the car will feel transformed. At the same time set the fronttotal toe at 2mm toe out. That’s about all you can do at this stage.
2. Nextcommitment level is damping. Problem is damping requires a spring decision simultaneouslyusually and sometimes also a strut top decision, so here’s the bit where lotsof consideration comes into it. Depending on budget you can go for coilovers with adjustable tops (solvingspring/ damping and front geometry in one go) eg KW clubsport for off the shelf options thatinclude tops or you can use K-mac, ground control or suspension concepts topsand adapt them to the strut/coilover of your choice. Out of those I think onlyK-mac make adjustable tops that can go straight onto say Bilstein B8 damperswithout modification. You can gocoilover retaining your OEM tops and there gain the advantage of being able topick and choose the springs of your choice but keep in mind that oem stut topsare likely in need of a change anyway and you wont be solving the cars severelack of caster and camber at the front. Or you can retain stock springs andjust throw in a set of Bilstein B8 dampers. It’s a budgetary and intended usedecision. Let us know where you fit withwhat you’re prepared to spend on this step and we can advise you regarding bangfor buck, or optimal spring rates, or which strut tops to choose etc.
3. This stepis kind of contingent on the one above. If you have adjustable tops then youmight already be happy with front geometry. If you want more though or you wantedto stay with OEM tops then you can find some geometry gain underneath the carif you inclined for a bit of engineer DIY. Fitting Audi RS TT balljoints to theOEM wishbones gives you roll centre correction and an additional degree of negcamber. You can also fit an eccentric bolt to the back of the subframe to allowyou to get a bit more caster. At this point if you’d stuck with factory springsyou could also find some springs for the rear that are lower and stiffer tooand really get its arse on the ground which will make it a lot more planted onfaster corners on the track.

After all that the carwill be hooking and anywhere within that sequence if you were doing some trackstuff it’s a good idea to find some nice light track rims and get some R specsemi slicks. A good tyre size in legit R spec semis is 225/45/16. That’s areally common race tyre and allows you to buy second hand semis from race tyrecompanies eg Levens for cheap. Finding 16 inch x 7.5 in 5 x 100 PCD ET35-40 isthe hard and expensive bit. Allternatively you can find 15 inch x7 inchrims easy enough for 205/50/15 tyres. With the above suspension stuff onsomething like yokohma A050, Dunlop DZ03G, Toyo R888R or even Nankang AR-1’syou will be running rings around most guys at the track in your class.

So next thing is enginepower. RE your exhaust question, put itthis way. Yes a continuous 2.75-3 inch system is the best – theoretically andin practice most of the time. YET, Ihad a custom code stage 1 tune, 3inch dump and 200 cell cat feeding into thestock back section where I’d just done a muffler delete and had fitted a parallelMBC to clip the overboost with that tune to 21psi and I have never had an enginethat has gone that hard. Since then I’ve had stage 2 generic tunes, customstage 2 tunes with bigger injectors and pumps, and now even have a K04-001turbo with the old APR tune and a full 3inch into 2.75inch system, and none ofthem can draw over 180g/s through the stock maf. The stage 1 tune on the stockback section exhaust and a bodge to prevent over boost made over 190g/s withnot a spec of timing pull. Go figure –that still has me baffled. The key isthe dump and cat. That’s the engine power equivalent of fitting a rear antiroll bar for handling. If you whack on a 3inch dump and 100 cell cat you are90% of the way there and that would work best with a stage 2 generic tune. Butat the end of the day after laying down the bucks on full exhaust systems andcustom tunes etc I reckon the car would be max 0.5sec quicker around southcircuit on engine power alone. The time (and fun) is all in the handling/tyresso I’d say put the dollars there initially and don’t obsess on power first.

[simon k]

..... and an oil cooler, our cars have a water to oil heat exchanger - my car's temperature gauge would creep up after 2 laps at Winton and it'd cut power until I fitted an oil cooler, now no problems

[sambb]

I concur.

[triode12]

dunno sorry, I've only had the one type, I went with what I found searching on here

Thanks Simon, I got the 70K one - did a search on the forum and people are saying that the 70K one is enough and not too stiff for normal driving.

[triode12]

If you want to dotrack stuff then I'd go for the chassis mods first. You'll have more fun with agood handling car and a good handling car on good tyres is way quicker than astock chassis Polo with 300hp. The OEM brakes are actually fine at firstprovided you have decent pads and fluid so you'll be good there initially.....

Hi Sam,
Thanks for taking the trouble to write such a comprehensive reply! It is much appreciated.
I have just purchased all of the necessary Superpro bushes thanks to Simon's recommendation.

I was considering doing the coilovers before the tune actually. I was thinking of getting Bilstein B16s with adjustable damping. I read that that KW coilovers and it's cheaper variants (ST coilovers) were hard to get parts for and re-built easily in Australia and that Bilsteins are much easier. My mechanic has suggested BC coilovers as budget alternatives.

I have a bit of a crunch in the gearbox going between 3rd to 4th since my mechanic changed the transmission fluid for me so I will be going back on Tuesday to see if it needs a bit more fluid put in. Also getting a bit of hesitation on acceleration and have bought replacement PRV and hose as they are leaking otherwise, it might be caused by a dirty MAF.