XR - Problem solving - Updated 15/4/07

pablo · Post by **pablo** » Sat Mar 24, 2007 4:24 pm

This is what we have done todate in an attempt to sort out this problem.

1. Replaced all cooling hoses
2. Changed radiator for a Scorpio cosworth one
3. Replaced viscous fan with twin electric ones
3. Fitted new expansion tank and cap

No joy :x

Today finally got round to having a sniff test and it came back with trace readings of CO2 in the expansion tank.
After talking a mate who had a simular problem it turns out that the head could actually be lifting under full boost. Which is why it only happened whilst driving around a track.

duncan · Post by **duncan** » Sat Mar 24, 2007 4:44 pm

what does that mean - tighter head bolt settings? - or isnt it that easy?

pablo · Post by **pablo** » Sat Mar 24, 2007 5:59 pm

We were going to remove the heads change the gasket, fit new head bolts with tighter torque settings but now you've mentioned that we may, time allowing try torqueing up the head bolts again to see if this helps before stripping everything down.

Thanks for the idea :thumb:

Post by **Stuart** » Sat Mar 24, 2007 8:53 pm

RichF

What is the shotgun method?

pablo · Post by **pablo** » Sun Mar 25, 2007 6:34 pm

Another interesting day spent with the car. The aim for today was to re-torque the heads with a higher setting.

As we were putting it back together Al noticed that one of the rockers was seriously cracked

We did have a couple of spares so this was changed.

Whilst we were at it we thought we would change a few graphics ready for the season.

pablo · Post by **pablo** » Mon Apr 09, 2007 10:03 pm

After cur last venture out on track at Donny and the head gasket blowing, it's back to square one. We should have the heads off and skimmed by this weekend, as long as the new gaskets and head bolts arrive by the end of the week, it should be back together by the end of the weekend.

Some people may say why do we keep bothering, why not get cossie instead.....It's simple we want a car that we can work on, something we know yet something different. Out of all the turbo conversions that have been done on sierra's our's is amongst the rarest along with 2.0 dohc turbo technics conversion. But more importantly for us is that ours uses the same size turbo as the RS200 rally car.

We know our car can be quick, we can feel the improvements which we have made to various aspects of the car. We have changed every part of the suspension except the front spax adjustable shocks. (Which hace been on the car for over 8 years, 6 1/2 stansing in a barn).

We have managed to take the handling of the car from being too soft with excess under-steer leading into over-steer with the inside rear wheel lifting......Cadwell

Mild under-steer with lift off over-steer but generally very stable.....Donnington
(Uprated lowering springs 25mm all round, KYB rear shocks fited).

Less under-steer and generally flater through bends, improved braking....Snetterton
(sierra cosworth front anti-roll bar, escort cosworth rear anti-roll bar, custom made, by myself, front and rear strut braces, Scorpio cosworth front and rear brake conversion)

Very direct and responsive turn in with no under-steer, but massive amount of over-steer....Donnington 8/4/07
As we are currently running with different tyres front to rear, budget tyres, we consciously swapped them around in an attempt to dial out the under-steer.

Next week a set of 4 Avon's are going on to test the general handling of the car running the same tyres all round, before changing the front shocks.

Ultimately we intend to run Kuhmo KU15 MX road / track tyres

Before buying these we are going to use the Avon's as test tyres. It may turn out that the car handles better, for our driving style, running different front to rear. We have got the back to stick and the front to turn in, if we can get the right set up where both work, then the car will be awesome on a track.

The graphics were roughly designed and sketched out before we had the car. The reason was simple i wanted get get sponsership and i had at the time 3 companies in mind. I felt that it would be easier for a company to visual their name on our car if it already had grahics on than if it was without. Our current sponsership deal came about after two events, without the car going on track. We unveiled it at Ford Fair last August where i spent alot of time talking to Fitz from Top Boss about the car and what we planned to do. 2 weeks later were at Donnington for the Rs show and Fitz was again there. That day Al took his sierra Gt out on track with some success. 2 weeks later again we were at Silverstone for trax. This is where the sponsership deal was struck....What a happy day that was.

So there you have it, even though we have a problem with the car whilst attempting to rectify it we are still developing and improving other areas.

Post by **Stuart** » Tue Apr 10, 2007 12:09 am

Interesting to see your thoughts on the tyres. I started with budget stuff to try and learn about the car at lower speeds, but have only ever used matched sets. Currently using Dunlop Formula R's which are superb but pricey compared to others. For cheap grip, have you guys ever tried Colways? Bloody superb in my book. Really liked them for regular track abuse

GT4Dave · Post by **GT4Dave** » Tue Apr 10, 2007 12:29 am

I had a similar problem with my first celica,,it would drive around normally not missing a beat,, but as shortly after hitting boost i would get water shooting out the header tank but as soon as i slowed down and drove normally it was fine.... it turned out to be a small 1 inch crack in the block in no2 bore,, small enough not to affect anything driving normally,, but as soon as i was on boost forced air pressure out of the bore and into water system of the block forcing the water through the system and out the tank.

duncan · Post by **duncan** » Tue Apr 10, 2007 7:20 am

stuartstaples wrote:Interesting to see your thoughts on the tyres. I started with budget stuff to try and learn about the car at lower speeds, but have only ever used matched sets. Currently using Dunlop Formula R's which are superb but pricey compared to others. For cheap grip, have you guys ever tried Colways? Bloody superb in my book. Really liked them for regular track abuse

Colways are good but you wont be allowed on the ring with those.... so something to bear in mind.

Post by **Stuart** » Tue Apr 10, 2007 12:24 pm

Their intermediate tyre is road legal Dunk. Any reason they wouldn't be allowed?