dewismotorsport's Astra coupe

Snetterton race day got off to a crap start, weather was terrible so swapped to my wets only for 3 of the studs snapping when torquing them up, looks like this has happened over time by the shear face, must of been a knock on effect from crash and joints and shaft failures. Either way very lucky not to happen on track. Quickly chiseled the old snapped bits from the hub and un wound from the back with mole grips. Sourced some spare wheel nuts and managed to get out in the last qualifying session. Due to missing my own meant I had to start at the back for both races.




Few pictures from a very wet qualifying







Race 1, started at the back in 38th place setting off I get into 3rd gear and went to change into 4th and the gear cable end popped off again, so I was then stuck in 3rd gear for the whole race, made the most of it, trying not to blow m,y engine up on the straights feathering the throttle. I fought my way through the pack and finished 17th.






(not the best watch)

Race 2, rain had stopped but circuit was still slippy and damp but with a dry line, I made the call to stay on wets while 70% of the grid changed to drys. I again started at the back in 38th, nursed it off the line and through the gears hoping my zip tie fix would hold, got myself up to 12th only for the cable end to come off again 2 laps from the end leaving me stuck in 3rd again so I carried on and finished 13th narrowly missing out on 3rd in class B






(better watch)
 
Race prep for the next race, Silverstone GP 6 hour team endurance race on the 26/10/19

Whipped the old cables out, you can see the plastic clips have broke on the cap and lets it pop off, new cable on route via a sponsor


New wheel studs fitted all round to be safe, also whipped the pads out, removed the glaze on the table linisher and re fitted





Also made an adaptor to lower the front camera as you can't see the best out the front


Other trivia stuff like re doing the headlight alignment as race finishes in the dark, wider 16mm front spacers as the 12mm still allowed the tyre to rub on inner chassis leg
 
Long overdue update sorry!

So the Birket Silverstone GP 6 hour endurance race was a very very wet one!

As a team we worked well and all cars performed well, I did a hour and quarter stint and the car was faultless, handling in the wet was un real and managed a 2.50 in traffic which was a top 10 time which I was happy with as there were plenty of faster cars such as radicals and such like.

Race was cut 20 minutes short unfortunately which didn't work in our favour as we were running in second in class but lapping 10 seconds a lap faster than the team in 1st so only needed one more lap to overtake them. Either way we finished second in class so still a great result.





That was the last race in that car for the season so time to take in apart again and improve some bits, mainly the underpowered engine, at its peak this engine made 267bhp but when changing engines I had the injectors cleaned, didn't realise how bad they were and once back in the car caused it to run really rich with a 10.2 to 10.3 AFR at full throttle, this must of knocked power down to more like 230-240bhp so putting right near the bottom of my power to weight class (240bhp per ton after race weight with me in it).

So with the engine out it was time to strip the engine down and build a better one.
Stripped all my spare Z22SE's to find the best crank, cams and head


First job was to strip the head, valves all out and decided to cut off and weld up the un used EGR valve




Next job was to start porting the really restrictive exhaust manifold ports, then smooth the casting marks out on the inlet side and combustion area. Clean the valves up and re lap. I've fitted Saab B207R exhaust valves as they are sodium filled better at dealing with higher temps.









Then into the parts cleaner before re assembling, used Dbilias motorsport uprated valve springs so that can up the revs to 8k rpm




With the head complete it was time to build the short block, I'd bought a Saab B207R block some years ago as I wanted to run the under piston oil squirters to aid with cooling, decided to take them out before the block went to the machine shop and turns out all the springs inside had either failed or were about to so had to buy new ones.
I'd bought some forged pistons about 4 years ago so took them down to the machine shop to have the block re bored to suit the +20 thou pistons.
I also bought some Eagle steel rods at a similar time so dug them out the spares cupboard, went to assemble to to soon find out they won't fit. I was told they were for the Z22SE but only when getting the pins out I soon realised they weren't. Turns out they are for the American 2.0L turbo LSJ engine which runs a larger 23mm pin instead of the smaller 20mm pin.
So all in all I'd had a nightmare and I had to think fast as it was fast approaching the mapping date of the 31st of march with the first race on the 5th of April.







So onto plan B, take apart the engine I had been using as it's a solid low mileage (53K) one and basically change the rods, Saab head gasket, ARP head studs, oil pump side cover gasket and bolted the head on.
While the engine was out I stripped the sound deadening off the bulkhead and gave it a quick squirt of paint and re made a plate for the water pipes.
I also took the diff to Gripper to get a service and have the ramp angle change to make it more aggressive.
Had some spare ARP flywheel bolts from a old C20LET engine so trimmed them down to suit and fitted.





While the engine was out I rebuilt the gearbox into the low milage box off the vectra b so stripped the shafts out and changed the bell housing, modded the housing to take the front gearbox mount and drilled for the larger breather.
I also sourced a 4.41 final drive and crown wheel from a American Saturn Vue so built it all back up, should be a lot better on track now as always found 3rd and 4th really long with the 3.95 fd.







Next improvement was to make a larger inlet manifold, previous design worked well but I wanted to future proof myself and give myself as bigger volume as I could, 3" inlet and 2 1/2" outlet (from charger). I've designed it around potentially running the throttle body post charger if thats possible





New injectors, yank ones that flow the same as VXR blues, didn't end up using the heat shields.
Engine and box assembled ready to go back in, once back in fitted inlet up and spent far too long messing about with the dipstick tube to get it to sit how I wanted.
Inlet piped up, blow off valve boss welded on and inlet temp boss moved into inlet pipe





Other jobs were to fix the small leak from the fuel rail, the after market dash fittings only have one seal on one of the fittings weirdly, worked for a while but then leaked, so cut down an old standard fuel pipe and then on top of that I added a injector seal that when done up acts as the seal and works a treat.
Bought a new ITG enclosed filter, really wanted this to help reduced inlet temps further, I'm happy with inlet temps currently seeing a peak of 45 degrees after a 20 minute race but I'd like to get down into the low 30 degrees if thats possible so had to add a 3" cold air feed, hole sawed the inner wing to allow space so had to make a smaller 1 litre washer tank





So I needed a feed for the filter so made up a feed box which takes air from the intercooler cut out, meshed it to stop it sucking in all the dead rubber on the track. Siliconed and sprayed the panel and mesh black after the picture.





Quick test start and soon found out the throttle body relocation wouldn't work as it would need a second throttle plate on the end of the charger still because when the throttle is shut it just pumps air out the BOV, I made it so it unbolted and the feed pipe was swapped from the charger end. May re visit this at a latter date but for now BOV has been removed.

Needed more camber on the front coilovers and wanted to do away with the camber bolts as I find they can slip under hard driving, die grinder'd the holes longer and removed the tabs.
Also weighed the car and corner weighted it, I literally can't get anymore weigh out of it so I need to run 290-295bhp to be top of my power to weight class of 240bhp per ton after race weight with me in it.






So in the need to up the power I've added a much smaller 2.7"pulley, plan with going that small is to get good power from low down with the opportunity to limit the revs if need be to get the required power figure I need. I have the option to run unto 8k now with the valve springs but current cams may not be perfect that high up but I have bought a over sized alternator pulley to prevent me destroying the alternator if I do go that high



So with this Covid-19 crap dragging on, mapping has been canceled twice so I've dug out the old corsa turbo 3" exhaust, so will get round to making a new system for the astra before it does get mapped as thats one less restriction, current one is 2.5"


So also with the boredom of this pandemic I've had a few ideas, first off was to buy a Saab B207R engine so I could use the head, and crank for my shelved forged engine. The Saab crank has the correct stroke for what my LSJ pistons need, just need to buy some LSJ steel rods and a Saab TTV flywheel I'm all sorted. Bought this 82K engine off eBay with the plan to take the crank and head off it, will port the head at a later date for the forge engine build


Then bored on eBay one night this Saab 9-3 2.0L turbo B207R came up and ending the following morning, last few seconds bid and it was mine for £400 runs and drives just has a judder below 2k rpm when warm. Plan for it is to use the full engine loom, coil pack, sensors and T8 ECU and use the T8 suite to self map it. Basically a cheaper version of OBD tuner as this software is free. Might not work but speaking to some people who have mapped these ecu's they seem to believe it will work fine. I'm happy being the test dummy as nothing ventured nothing gained.
The box of tricks allows me to talk to the ecu once I knock up a OBD adaptor lead. Will copy the standard map of the car and then see how kitballows me to change it on the running car before I break the car for bits.



 
Last edited:
Top