So I'm obviously a bit odd, because unlike many, I believe a JTS to be worth actually bothering with, and so that brings us to another episode of me meddling with it.
A long time ago I put it on a dyno
and got pretty much what I expected.
A bit later I then had the head rebuilt
- carbon horror galore - and as well as being valuable maintenance, it ran a bit smoother and behaved a bit more linearly.
Now I've completed that line of work by going to see Gus at Alfatune, and doing this:
- Supersprint 4-2-1 manifold
- 300 cell sports cat
- Full stainless system
Gus by the way is a great chap and it's been a pleasure to do business with him.
So, what do I think?
Well, cop out - it's too early to have formed a proper opinion yet. I've only done about fifty miles, and most of that was motorway. Another dyno run is due in mid-Jan and in the meantime I'll be gathering the usual numbers about economy as well, for what it's worth.
First thoughts, however.
Let's try and get the sound out of the way with, since this is the most obvious change. It sounds like a completely different car - quite surprised in this regard. At idle it's much more heavyweight, in a good way. In fact that sums up the sound in general - quite deep and refined, if that makes sense. A reassuringly expensive sound!
Volume wise, compared to OEM, it's loud. I don't have much else to compare it to - broadly speaking, it seems in line with some respectable stuff I've seen on a few GTAs.
The stock JTS can be a really quiet motorway cruiser where you can almost forget about the engine over the road & wind noise, but liittle chance of that at the moment. On the other hand, with the stereo on at reasonable volume, I think it would cease being at the front of your mind. At low revs like say 30mph in fourth, it's also a lot more tolerable. Shame the JTS doesn't have six gears.
I'm still deciding exactly what I think of this, and I might find it changes as it beds in (builds up with carbon) too. Initially, if I'm honest, it's a bit much for my tastes, but I'm staying open minded about it. As it is now, it's right at home giving it beans on a B-road, less so on a motorway or parking in a street, but that's inevitable I guess.
Other audible characteristics then? Hard to describe, but the overrun is nice, and a bit of crackle etc when inching through town. It's a lot
more of an experience, and you get much better feedback about everything you're doing. I like this side to it very much - good fun! I'll try and get some audio captured soon.
So, what's it like to drive? Well the sound changes have been a fair distraction thus far, also impacting slightly on how I drive, and I really want to try it out on the familiar twisty stomping grounds back home (I'm on holiday right now), but so far: it's a thumbs up.
The best way I can describe the most apparent change is 'more linear'. The JTS and I think the Twinny too take a while to get going unless you go out of your way, drop a cog and get the revs up in advance. If you've got one you'll know what I mean - notice the throttle's been pressed, think about what day it is, remember that we're a car, and finally off we go. Most JTS cars are also extra hesitant too - see the flat spot in my torque curve - even though on mine we probably got rid of that already. Anyway, this just goes a lot better with pretty much none of that. It really feels like the mid-range is a lot better propped up.
As a result, it feels significantly quicker, but it's going to take more time with it to try and put a number on that.
I'm also told it can potentially handle V-Power now too, so there's another experiment to try.
Plenty more updates coming on this, then, and I'll add more thoughts as they develop. Also whatever happens to me when the O/H hears it