Mazda RX8 Fast Road & Track Project
Discussion
Thought it was about time I made a thread about my Rex as I've been enjoying it for around 8 months now. The plan was to buy something I could use for fun on weekends and also on track as I was keen to start doing trackdays. I'll start from the beginning with a few posts to bring us up to today then update as things progress.
It was two days after my birthday, in mid January, when I went to view my first RX8. I'd read the owners club forums to learn about what to look for in terms of problem areas, then promptly ignored some potential warning signs of a weak example, and bought it. Essentially, it took a while to start when hot, one of the key things to walk away from when buying a Rex. However, after filling the tank and giving it a good run on the way home, it did seem to improve. Did it just need some decent fuel pumping through?
The day of purchase - I even got some snow thrown in for free!
So with my first trackday just over a month away it was time to see what needed doing in terms of preparation. With limited free time and no urgent problems apparent, I decided to run the first day without any work to get a baseline and see what the car is like. That way I can see what difference my changes make. The only thing I did was to start premixing.
Premixing is rather common amongst "rotorheads" as a way of reducing the carbon build up in the combustion chambers. By design, the wankel engine burns oil during combustion. However, normal 4 stroke engine oil is designed as a lubricant and therefore doesn't burn under combustion, which can leave deposits in the combustion chambers, leading to seal damage. This is also the reason you shouldn't run fully synthetic oil, as it's resistance to break up at high temperatures makes it the worst culprit for leaving material where you don't want it. The solution to all of this is to introduce a small amount of 2 stroke oil into the fuel mixture, which is designed to burn cleanly. This is done either by literally squirting it into the tank when filling up, or by plumbing in a Sohn adapter. For now, I'm using the former method, which certainly raises some eyebrows at petrol stations, especially when my oil is kept in Lucozade Sport bottles
The first batch of oil (both 4 stroke and premix) came from the lads at Essex Rotary, who advised of rough quantities to use for road and track use.
So I was now ready and looking forward to the first track outing for both me and the Rex.
It was two days after my birthday, in mid January, when I went to view my first RX8. I'd read the owners club forums to learn about what to look for in terms of problem areas, then promptly ignored some potential warning signs of a weak example, and bought it. Essentially, it took a while to start when hot, one of the key things to walk away from when buying a Rex. However, after filling the tank and giving it a good run on the way home, it did seem to improve. Did it just need some decent fuel pumping through?
The day of purchase - I even got some snow thrown in for free!
So with my first trackday just over a month away it was time to see what needed doing in terms of preparation. With limited free time and no urgent problems apparent, I decided to run the first day without any work to get a baseline and see what the car is like. That way I can see what difference my changes make. The only thing I did was to start premixing.
Premixing is rather common amongst "rotorheads" as a way of reducing the carbon build up in the combustion chambers. By design, the wankel engine burns oil during combustion. However, normal 4 stroke engine oil is designed as a lubricant and therefore doesn't burn under combustion, which can leave deposits in the combustion chambers, leading to seal damage. This is also the reason you shouldn't run fully synthetic oil, as it's resistance to break up at high temperatures makes it the worst culprit for leaving material where you don't want it. The solution to all of this is to introduce a small amount of 2 stroke oil into the fuel mixture, which is designed to burn cleanly. This is done either by literally squirting it into the tank when filling up, or by plumbing in a Sohn adapter. For now, I'm using the former method, which certainly raises some eyebrows at petrol stations, especially when my oil is kept in Lucozade Sport bottles
The first batch of oil (both 4 stroke and premix) came from the lads at Essex Rotary, who advised of rough quantities to use for road and track use.
So I was now ready and looking forward to the first track outing for both me and the Rex.
Late February. Oulton Park. A crisp morning that soon burned off and turned into an awesome day for driving.
Sadly I have no pictures of the car on track. The MSV shots weren't all that good and I didn't spot too many from 3rd party sites either.
I attended the trackday with a group of guys from work, we have a motor club within which I'm now responsible for trackday organisation. Think there were around a dozen of us in total on this day.
PHer McSam brought along his E36 for some fun as well. We each drove both cars, and I got a good idea of what I can do to improve my car given the work he has put into the 328i.
Managed to get a good number of sessions in, getting used to the car, how it behaves, and things like the pedal position for heel-toeing. I was very impressed with how the Rex performed given the sum I paid for the car and the fact I'd done nothing to it. The only thing to go wrong was the exhaust, which ended the day a lot louder than it started. Don't think I'd have got through a noise test by the end of the day!
With some time before the next planned trackday, the next job was to sort the exhaust. I also began to make a list of things I'd like to attend to in the not-too-distant future, mainly known weak points from my forum research. More to follow...
Sadly I have no pictures of the car on track. The MSV shots weren't all that good and I didn't spot too many from 3rd party sites either.
I attended the trackday with a group of guys from work, we have a motor club within which I'm now responsible for trackday organisation. Think there were around a dozen of us in total on this day.
PHer McSam brought along his E36 for some fun as well. We each drove both cars, and I got a good idea of what I can do to improve my car given the work he has put into the 328i.
Managed to get a good number of sessions in, getting used to the car, how it behaves, and things like the pedal position for heel-toeing. I was very impressed with how the Rex performed given the sum I paid for the car and the fact I'd done nothing to it. The only thing to go wrong was the exhaust, which ended the day a lot louder than it started. Don't think I'd have got through a noise test by the end of the day!
With some time before the next planned trackday, the next job was to sort the exhaust. I also began to make a list of things I'd like to attend to in the not-too-distant future, mainly known weak points from my forum research. More to follow...
So after the first day at Oulton Park, I had to tackle the blowing exhaust. Decided I was going to try to change this myself, as I'd like to do as much of the work on the car myself, both for the satisfaction of a home project, and to keep labour costs down.
The first mistake I made was thinking I wouldn't be so unlucky that I'd need a new midpipe, which includes the cat. So I ordered a Toyosports catback. This arrived a couple off days later along with a fresh pair of Michelin PS3s.
Once I was under the car, my mistake was realised. Not sure if you can make out the break, but it's around the silencer, which is in the midpipe, bugger.
So then it was back to square one. On the basis that I really only want to change the exhaust once (limited by space and lying under the car to do it is not ideal!), I went for a KKS midpipe with sports cat.
I therefore ended up with the following to be fitted. Note the lack of silencers, this excited me
When I eventually got the old midpipe out I could see the extent of the damage. It appears the cat had made a break for it and ejected itself all over Oulton Park, with only a few gravel sized bits left inside. On its way, it did this to the silencer
With that mess out of the way it was time to fit the shiny new stainless items. All went together perfectly with one exception. As the Toyosport catback is a larger diameter than standard, it can often foul on the exhaust shrouds, its just luck when you hang it whether it touches or not depending on where exactly it sits. Given the burning smell that signified melting plastic once I started the car for a leak check, it was obvious I need to make some adjustments. I ran around like this for a week or so while I hacked away at the rear edge of the shrouds in my spare time.
All back together a few days later
The first mistake I made was thinking I wouldn't be so unlucky that I'd need a new midpipe, which includes the cat. So I ordered a Toyosports catback. This arrived a couple off days later along with a fresh pair of Michelin PS3s.
Once I was under the car, my mistake was realised. Not sure if you can make out the break, but it's around the silencer, which is in the midpipe, bugger.
So then it was back to square one. On the basis that I really only want to change the exhaust once (limited by space and lying under the car to do it is not ideal!), I went for a KKS midpipe with sports cat.
I therefore ended up with the following to be fitted. Note the lack of silencers, this excited me
When I eventually got the old midpipe out I could see the extent of the damage. It appears the cat had made a break for it and ejected itself all over Oulton Park, with only a few gravel sized bits left inside. On its way, it did this to the silencer
With that mess out of the way it was time to fit the shiny new stainless items. All went together perfectly with one exception. As the Toyosport catback is a larger diameter than standard, it can often foul on the exhaust shrouds, its just luck when you hang it whether it touches or not depending on where exactly it sits. Given the burning smell that signified melting plastic once I started the car for a leak check, it was obvious I need to make some adjustments. I ran around like this for a week or so while I hacked away at the rear edge of the shrouds in my spare time.
All back together a few days later
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff