Quote:
Originally Posted by Capt Spaulding
@ grumpysnapper: I like your development model. If you have a few minutes, I'd be interested in your experience running the Harrop on the stock mechanicals. Specifically, I'm interested in the possibility of running something like that on a BRZ that serves as a light GT car. Engine longevity and drivability over multiple 4000 mile road trips and that sort of thing. No off pavement except for the occasional gravel parking lot. My first order of business is the suspension. I'd like to keep the stock ride height, or even add a couple of fractions to the wheel travel, and keep the basic character of the car. I'm waiting for 949 to birth the Xida coilover baby so I can give them a close look.
Not willing/able (at this point) to go with a built motor. That might torpedo the project, but it's worth a look/chat. And, hell, I'm not laying awake at night now pining for more ponies. |
Hi mate, happy to give you my perspective.
One of the big benefits of the Harrop is that it works really well for a variety of different potential uses.
It looks OE, is supplied very complete, has been very well sorted.
Tuning is not difficult, and the car will run very reliably.
You are not chasing dyno numbers, so that puts you in a really good position.
Because the power delivery is fairly linear in comparison to many turbos, lots of the drive line stresses seem to be lessened slightly.
Bolting one onto a standard engine on its standard large 95mm pulley (and even perhaps down to 85mm) should not be problematic.
The extra power will make you very very happy.
A new header is important, and the recommended ACE header is very good...but not cheap. The rest of the exhaust is sort of optional, but most of the aftermarket options seem to sound....horrible...and loud.
Turbos obviously have a slight damping effect on exhaust noise...a supercharger seems to do the reverse.
When/if the time comes get a custom build in (lightweight) stainless, it will last better and sound better than titanium (ask me how I know...)...and will still be lighter than the OE system.
A freer flowing cat would be good.
The standard cooling system can cope very well, but the addition of an oil cooler is not a bad idea.
There should be no real issues with the rest of the drive train either, but if your clutch has done a fair few miles, then installing a slightly heavier duty version could be something to think about.
I spent 3 very happy years on the 85mm pulley with zero issues on an internally standard engine. When it was pulled out and inspected then rebuilt for the new bottom end, the builder said it effectively looked new.
Having said that, I am anal about oil...so it gets changed along with the filter every 5000km. And I only use a high quality oil (Mobil 1).
Standard brakes are fine for your usage, just a set of good pads and good fluid...until you work out if you need/want 'more'.
Which brings me to wheels/tyres. Put simply one of the very best decisions I made early was to ensure a decent tyre with a decent sidewall...for hard road use (or even soft) a working sidewall is magic. It solves so many problems...by not creating them...
I went for 16" forged alloy, and was so happy I ended up getting 2 sets.
The only issue with 16's is brake clearances later if you do decide to change set ups.
Luckily you are happy with standard road height (or slightly more), the car does have limited travel, so road height is crucial.
One thing I do highly recommend is lowering the final drive, I went for a 4.66, but anything around there would be good.
I felt the 86/BRZ is too highly geared...even with a (low psi) supercharger.
Weight is also an important factor for me, the supercharger adds around 28kg (I think), the oil cooler another 4kg if you add one... etc
I made a pact with myself to remove the same amount of weight that I added to the car...and hopefully more.
It's worth the effort, and relatively easy. Sort of. A rear seat delete, a light weight battery and a slightly modified exhaust would get you most of the way.
My road trips are usually about 5000km each of backroads tarmac and dirt...in all types of weather. Reliability has been %100 over 30000km.
Hope this helps, but let me know if there is something else.
Lyndon
PS. The single greatest compromise that I made with my car is using an alloy prop shaft.... you save weight, but the noise transmission is ridiculous...and probably not really worth it!