Admin

sinbad
impressive time, great to see MR2's on the track where they should be!!
 
i got a 1:11.7 (natsoft) with street tyres and 160rwkw @ 5psi

How did you manage to only run 5psi? I thought that the MR2 wastegate actuator was 10psi minimum or thereabouts

3.0L V6 camry powerplant, stock is 145kw at the flywheel, with 5psi 160kw at the wheels. peak power @ 5,000rpm
 
nothin too fancy with the handling, eibach springs and koni shocks, but emphasis on chassis rigidity and aggressive alignment. with semi slicks i think there could be room for a 1-2 second improvement, definitely lacking grip with my street tyres.

Admin
Ah that explains it. That's a great time for street tyres.
Will we see you at the MTC next year?

thanks! here is the vid if you are interested. http://youtu.be/1IsjAJWEy28
you can see how twitchy the car is with street tyres. also notice how i take the horseshoe in 4th gear, the advantage of 400nm at 3000rpm.
im dedicated to street setup, drive to the track, drive home, no changes :)
(other than removing spare tyre and jack etc)
not sure yet, thats a while away. although i am looking at attending the NSCC day 31/05/14. how about you?

Hi guys,
I have a strange problem with my engine and need some opinions.
I drove it at Eastern Creek a couple of weeks ago and it ran fine though when I drove into the pit lane after a cool down lap after the third session, it stalled. I then clutched it as I was still rolling and it was spluttering a bit. It had run OK when I was racing. When I went to drive in the 4th session, it wouldn't start. I gave up and winched it onto the trailer.
I checked it yesterday and the plugs were fouled, as I expected. I then put some new hotter plugs in and it still wouldn't start. I was perplexed.
I went through the normal fault finding process and came to the conclusion that the compression in all 4 cylinders was very low - around 75psi
I checked a few things to figure out the cause and found that there was no inlet valve clearance - on any of them. The exhaust valve clearances were however all within tolerance.
I loosened the inlet cam caps until I had the right clearance (for testing purposes only - I didn't run the engine like this) and retested the compression and it was 190psi. This proved that the cam was holding the inlet valves slightly open when they should have been closed.
So my question is this - What caused my inlet valve clearances to change?
The engine had been running fine previously.
I have oversized valves. The only thing that I can think of is that the valve seats have relaxed after a few hundred KMs of hard driving. Any other ideas?
Should I just re-shim and keep driving? Everything else looks fine.

I would take the CAMS out to check all retainers and colletts are ok, then reset all the shims. Are you running shim under bucket?

I also agree with track mr2. Could well be a cam gear that moved. Certainly makes perfect sense. Hey track mr2, feel like helping me assemble a 2GR!
 

track_mr2
Did you check your cam timing at all? I don't think its likely that all four cylinders valves relaxed at exactly the same time and exactly the same amount to cause this issue. Even on race engines I've had from new I have never come across valve seats relaxing to cause loss of compression like that. Even high revving factory engines like motor bike engines don't have this issue. I'd check your cam timing, if your running adjustable sprockets maybe they have slipped if they are not the doweled types.

The timing is fine. I'm running standard sprockets. There is no clearance at all between the base of the cam lobe and the shim. Even if the timing was wrong, there should be some clearance. All 8 of the inlet lobes have 0 clearance.

I'll be taking all the shims out tomorrow, measuring them and ordering some thinner ones. I won't know the exact thickness I will need though I'll probably buy one set one size thinner and also another set two sizes thinner just in case.
Because race car! It never ends.....