The good and bad of the VW GTI - Stock and not so stock :)
Well, here we go. I've been meaning to write this up for some time, but now the car has been chipped so I figure now is a good a time as any. This is basically going to be my impressions on the various things I've done to my car. I spent many hours searching the internet for opinions on things, so I figured I would give back and post what my thoughts were on my mods. First you should know a few things. I purchased this '03 SilverStone 1.8t GTI for a few reasons. Mostly I wanted a car with form and function, while putting function a tad ahead of form. For instance I wanted the joys of a sporty car, but I needed four seats and a place to put a bunch of crap. The hatchback fit the bill. (It also helps that I really like the looks of hatchbacks) I also wanted a car that came with a turbo already. I figured it would be easier to get the kind of power of it that I wanted with out spending too much money on it. It seemed that there was a long list of bolt-ons for this motor that can make actual power. I also have a thing for Euro cars, I like the way they look and I really like the interior build quality. The next bit is a bit tough to explain, but the overall design of the car seemed to fit my mentality. The whole "Car of the people" thing really works for me. Also I wanted a really fun daily driver. I spend a good amount of time in the car, so it needs to be comfortable as well as quick on the B-roads. This really is the perfect car for me, so keep that in mind while reading my opinions.
First day of ownership (500 miles):
The car came from Texas to Michigan, so I got it with 500 miles already on the car.
(stock car)
The car was bone stock for 3000 miles. At first it was truly amazing for me. Second gear especially. There was this fun "kick" just as you crossed 2500 rpms. It was quite fun. Everything was really tight in the car and the ride was nice and smooth. The weakest point stock was most certainly the tires, but I will get to that in a bit. Next was the suspension setup. Once I felt more comfortable with the car I started to push it and the suspension really started to show its weak points. Basically it can be summed up with one word, "understeer". No matter what I tried it was just not possible to push it on corner exit. There was also a good bit of body roll when changing directions quickly. One of two things would happen. The delayed weight transfer would either lift too much on the inside front tire and then allow it to spin, or pull the front of the car off of its line. The big issue was simply the time it took for the body to get set. Other than that, the car in stock for was really a blast. One the second day, I went 400 miles, basically around the block. If that's not a testament to how fun this car is, then I don't know what is.
First Mod K&N air filter. From the beginning I knew I was going to modify the car a good bit during its lifetime, but being my first new car I was a bit hesitant. So I figured I would start small. For that I purchased a K&N drop in filter. Did the power change? I doubt it, but it did make cool "whooshing" noises off throttle 
In addition, it got me into the engine bay a bit.
Second Mod: Front End (1,200 miles sigh..)
This wasn't so much of a mod as a necessity. It snowed, water froze, and I slid rather slowly into a tree in the parking lot. I wasn't even going fast enough for the doors to lock, but the car just wouldn't stop sliding. and I slowly hit the tree. It was rather shocking.. The front bumper was damaged as well as the support beam behind it. So I purchased a new front end from the dealer and had it painted. Then I swapped it out. (Now I know what you are thinking, Why on earth did you go with the stock bumper again?! To be honest, I really didn't like any of the body kits. I really do like the way the car looks stock, can't help it.) This helped get over the fear of doing things to the car rather quickly.
(Look ma, no bumper!)
Third Mod: Plumbing (3,000 miles)
Once I changed that out, the fear was gone, and the craving was growing. So I started a plan. First up, plumbing. At 3,000 miles I installed a P-Flow filter, Neuspeed turbo inlet pipe, NS 60mm downpipe, and 60mm NS catback. I knew it wasn't going to get me much at the time, but I figured it would make for a good start for when I get the car chipped. These parts actually turned out to be pretty interesting. I didn't really gain any power (I was using a G-tech timer to get 0-60 and g-forces before and after the mods, the numbers were almost identical) but the power curve had changed significantly. The power came on much smoother which was good during autocross, but second gear lost a bit of its fun factor. The exhaust note turned out to also be quite pleasing. I think it really sounds good now actually. So while it didn't seem to get me any more power, all of the available power showed up evenly and even a touch earlier. Here is the dyno run with just those mods. (this was actually done 3 days before the car was chipped so this graph and the one later on can be compared pretty well). Just as a quick note, the install was really very easy of the new bumper. The hardest part was getting the lower lip from the old bumper on to the new one.
(exhaust dyno)
Fourth mod: Sway bar (8,000 Miles)
Next began my quest to kill the understeer. I had done my research and I had determined that a stiff rear anti-sway bar would help keep the front wheels planted and help with a quicker weight transfer. This is still one of the best things I've done to the car. I added the 28mm NS sway bar (now I almost wish I got the autotech light weight one, but I didn't have to drill for the NS one) and it helped tremendously with the body roll. The install for this wasn't too bad either, its just a pain to get that much of the car in the air in an apartment parking lot. Once on though, I could really start to feel the backend wanting to slide out a bit on throttle lift off around corners. This was a good sign!
(sway bar shot)
Fifth Mod: PSS9 goodness (10,000 miles)
Still on the quest for less understeer I purchased the bilstein PSS9 coilover set. Got a good deal from "Banks Performance". The install took a while for these. One thing that saved a bunch of time though was the autotech "Spreader Tool". Basically it's a $10 chunk of metal that fits in a socket that you can use to spread the collar that holds the bottom of the front damper. I can't really imagine getting the old dampers off without it. Please save yourself the hassle and just pick one of those up. The only other issue was getting the old strut out of the front passenger side wheel well. We had to flip the spring compressors upside down and compress the spring while it was still on the car. Then we had enough room to lower it out of the wheel well. Once they were on, it took a great deal of time to get the height adjusted correctly on all four corners. Since I didn't have a corner balance scale set, I had to do it with tape measures. I also counted threads on the shock bodies to get the height the same from side to side. After all was said and done the car was dropped about 1.25". A week later it had settled to about 1.5". Nothing was rubbing (including the front sway bar) and all seemed well. Next was getting the dampening settings correct. This took quite a bit of experimenting. Here is what I came up with. For comfort set the rear on full soft and the front to 3 clicks up from soft. This seemed to keep the pitching over bumps under control. However the downside is that this increased understeer. For auto-x it seems that full stiff in the rear and the same setting up front (3 clicks from full soft) seemed to be a pretty good combination. The downside to having the front a bit softer is turn in sharpness decreases, but overall traction increases. Over the year that I have been running this setup, they have softened up a bit, but not much. Oh, and one other note on the install, I didn't use the spacers up front from the stock ones, just figured I would mention that.
(Post Coil Install)
Sixth Mod: Tires: (11,000 miles)
The search for less understeer continued still. The new suspension bits really helped out, but it became painfully obvious that the car was out running the tires. After a bunch of research I ended up getting the Toyo Proxies T1-S tires. The choice ended up being between the Falcon Azenis and the T1-S. Here in Michigan it rains a good bit, so while the Falcons hold the dry pavement better, I was afraid to run them hard in the rain, so I ended up with the Toyos. I must say that these are simply amazing. This is by far the most effective mod you can do to your car for handling. I was blown away by how much grip these tires had. Here is where the real suspension experiments happened. With the new tires I could feel the effects of the different suspension settings a lot more. I could now actually dial in the understeer and oversteer of the car. The stock Continentals were robbing me of so much fun. This suspension setup with these tires was a match made in heaven! The next thing I started playing with was tire pressure. The T1-S tires are a bit known for not having the stiffest sidewalls. So to compensate on race day, I added more air. This helped turn in a good bit, but with too much air, they stopped gripping as well and we were back into understeer land. Depending on the track surface, I tend to run 44psi in the rear tires and 35psi or so in the front. Sometimes a little less if it's a bit greasy out. I can then fine tune that with the suspension settings. It really is great fun to be able to play with all of these settings and actually feel the difference. To sum up, stiffer in the back creates more oversteer, good for rotation, softer front makes for less understeer but also dulls the turn in. Everything is a give and take thing with suspension it seems.
Soon the dreaded Michigan winter came. I didn't want a repeat of last winter (and the tree) so I finally sprung for a set of steelies and snow tires. I ended up with GoodYear Ultra-Grip ICE tires. (15"x195mm). I kept the pressure in them at about 32psi, and I must say I had no troubles at all. I was even able to pull my buddies 240 out of the snow a few times (that's the other car in some of the pics). These ended up being very good tires for the snow. The only problem is that the sidewalls are very tall and very very very flimsy. There is very little real grip on dry asphalt let alone salted asphalt, but in the snow or on the ice they grip very well. Needless to say I couldn't wait for the snow to stop so I could get the Toyos back on.
Seventh Mod: APR goodness (24,000 miles)
Finally spring arrived and I had been saving up all winter, and the Tax refund finally came back. So now I decided it was finally time. Time to complete the puzzle and get the car chipped. I had gotten used to the power the car made and had been left feeling a bit wanting, so I broke down and did it. I purchased the DPP version of the flip chip and got Stock, 93 Oct., and the lockout feature. All I can say is "HOLY CRAP!" This was an amazing experience. The second gear joy that had been missing since the exhaust install was suddenly back with a vengeance. There was so much more power everywhere! The grin that had slowly started to fade was plastered right back on my face after the ECU upgrade. This was truly amazing. Here is the dyno run for it:
(as a quick note, this run was done 3 days after the run from above, under nearly identical conditions)
(after chip)
Here are the best runs from the two dyno sessions:
(before and after chip)
These numbers were actually a bit shy of what I thought I was going to get. I was hoping for 195, but 187 was pretty close. I think that the stock Cat. is really hurting me here. The only other plans that I have for power in the near future are pulley set and maybe a better gasket for the intake mani. However I am considering a new hi-flow cat. The only problem is that I need it to be 50 state smog legal, so for now I'm not sure. So to tell you the truth, I'm not sure what kind of advantage the plumbing parts really got me. Its tough to say without having bone stock dyno numbers to look at, and even then its not really a good comparison. However, I must say, this was one incredible mod, the car feels very different now in a very good way.
This leaves us with how the car is now. Things on the list to still do:
1) Very low end power in 2nd gear (sub 2,500 rpms) seems a bit lacking still. I'm going to look into the G60 14lb flywheel and a set of pulleys.
2) I still think the stock Cat is robbing me, so that makes the list as well.
3) I haven' done much for the looks of the car, so a small spoiler and "Joey Modded" headlights are on the list.
4) New Wheels, I will never get them though.. just too expensive.
Over all I'm very happy with the way the car behaves now. Its really just like I wanted it. Good times indeed.
Just for completeness I'm should mention the other "little" mods that I¡¦ve done.
1) Tinted side markers. They look good to me on a SilverStone GTI
2) Short antenna, cheap, but looks nice. It did hurt radio quality a bit, but I never listen to the radio.
3) Boost Gauge. (AWE tuning with column mount) I wanted to make sure that I had this before getting the car chipped. Just to keep an eye on everything. With the plumbing mods boost hung out at around 9psi and spiked at like 11psi. With the chip I've seen it as high as 18psi, but hangs out at 15 until 5500 rpm or so and drops to 10. (You can see the boost on the dyno runs above)
So far so good, I'll keep this updated if you guys want. Just let me know. Not that I'm doing anything really interesting with the car, but you never know.
I would also like to thank Steves European Automotive (www.steveseuropeanauto.com) for installing the chip and the helpful advice and Lidio over at Alternative Auto Performance (www.alternativeauto.com). Even though Alternative is a Ford tuner, they ran the Dyno sessions and were all very nice. Also thanks to AssSideways (240 owner) for the help and for convincing me to keep spending money on the car .
Thanks for reading! I hope someone finds it useful.
-Jake
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