Man, I don't get it. The ~150 lb weight difference doesn't account for that forward thrust differential. I know the GTI has a gearing advantage...
2nd gear @ 6500 RPMs
GTI (6MT): 59 MPH
FoST: 62 MPH
3rd gear @ 6500 RPMs
GTI (6MT): 84 MPH
FoST: 91 MPH
4th gear @ 6500 RPMs
GTI (6MT): 111 MPH
FoST: 118 MPH
....but that difference in weight and gearing doesn't seem like it should overcome a ~45 hp deficit.
Stratified Tuning's site shows that the numbers he claimed for the ST check out. How sure are you about your numbers? I have to believe that the dyno that produced those numbers for that setup read on the low side.
I know this is a huge simplification, but these two cars have 2.0 liter DOHC engines running K03 turbos, so similarly upgraded cars should yield similar horsepower and acceleration numbers.
After browsing through the ST forums and checking time-slips it does look like these cars are capable running with GTI mod for mod. If I were to bet, it sounds like the ST you ran was making a fair amount less than claimed. Full stage 3 on an E30 tune should have given him an edge. You didn't mention the ambient temps or if the guy had run his car right before he ran you; maybe there was heat soak and the ST's ECU is quick to pull timing/boost when the IATs creep up?
Ambient temps were low, like mid 50's, they were in a group cruising together going to a camp out before an airport dragstrip track day which was the next day. He had some extra fuel in the back in a gas can, and had 1 passenger, whereas I had none. I told him that didn't help him, but he refused to believe it as a viable excuse. I know it made some difference, but it still wasn't more than 200lbs, and that's not enough to make up for the hp difference either, let alone one that let me dive ahead by so much. He did hold on to me in 3rd gear pretty well (iirc), and it was when I shifted to 4th that I started really pulling away.
I don't know what it is, but there is something funky with those cars and they just aren't getting all that power to the ground.
Nah man, ST'a just need more power than GTi's to be just as fast; plain and simple. Last summer I ran an ST that was stage 1 when I was stage 1. I dusted him. Later that same summer he went full bolt (I'm pretty sure) complete with intercooler and no-lift shift with a freak tune (I believe) and I still edged him out with my same mods. Last I checked he was going big turbo but I haven't heard back from him. ST's are just slower all around
Even big turbo is really not that fast, not to mention I've seen tons of local guys go BT, only to blow their motor within relatively short fashion...I wanna say the fastest I've seen a BT ST go, last I checked (which I'll admit was a while ago) was something in the 12's around 119mph. I think the WR K04 car is in the low 120's, and K04 is definitely not on the same level power-wise as their BT, not even close.
Yeah it just seems odd. There's just so much that's similar between these two cars that people shouldn't be walking them so easily. It'd be great if there were an explanation out there.
They are very similar, and should be highly competitive, but just...aren't...wish I knew what it was.
I don't believe it's only the ST though, the RS I feel fits into the same category. The RS has a 60hp advantage over the STI and the Golf R, yet the RS is 13.4 @ 105, the STI is 13.4 @ 104, the Golf R is 13.6 @ 105...that's essentially identical. Yes, the Golf R weighs 200lbs less, but the STI is only 3lbs less, but even 200lbs does not negate a 60hp advantage. Their hot hatches just have some weird fucking voodoo shit happening that keeps them from living to their potential.