1991 Astra GTE 16v > BTCC tribute

[darrenh]

after several years of considerable malaise with my project cars, i ended up selling them at the tail end of last summer. i cant express how much of a mental health doldrum i was in plus how out of love i had become with the cars. i'm not being deliberately aloof and happy to discuss the ins and outs, but keeping it brief for the intro.

The above was spurred on after getting wind of a car coming up for sale, quite a special car in fact. ive known the owner since the year dot and in weird twist it contains the engine gearbox and exhaust from my very first GTE, that i sold to him way back in 2006 ! anyway, i got a tip off from a friend of a friend, then i message the owner saying "how many kidneys?" A deal for internal organs was agreed and since that day started jettisoning cars, parts, garage load of the stuff i had been hoarding for 10+ years to build a car of this spec.

in so far as that concerned, au revoir 1.6 merit auto



au revoir my version of christine, the silver 1991 astra GTE 16v.



then in october 2023 this was backed onto my driveway, with a metaphorical and literal sigh of relief from my lungs and brain.



its been a track day car for almost 20 years but has no historical provenance (in motorsport) The intention is to slather it in livery to ape the GTEs entered into the british touring car championship in 1989 by dave cook racing services, which ultimately propelled john cleland to his first BTCC title.

example picture at 1989 birmingham super prix



that being said about provenance, cleland has actually driven this car for a magazine feature in 2009, so thats neat !

[darrenh]

this is me back in january 2024 at brands hatch, which is only about 40 minutes drive from my place, and that drive was the first time i drove it, ha !





the car is packing some impressive mechanicals which i will go into detail, but it was quite an eye opening event. Most notably getting used to a front wheel drive car and which has a tendancy to oversteer at any given opportunity, even when accelerating. Most of this has been achieved by running without a front antiroll bar, double on the rear, plus a gripper plate diff, and coilovers on all 4 corners (mk2 escort turrets on the rear) tyres are dunlop direzza, so a very high end road legal cut slick. theres some seriously accurate turn in available

[darrenh]

from memory group A regs (which were used up until 1990 in btcc) allowed for a +2 inch wheel. most of the cars ran centre lock BBS wheels, as did the astras (which you can see in my first post). centre lock hubs are actually available for the astra / kadett but as i already blew the family fortune buying the car, and quick pit stops serve no purpose to me, i decided to go "for the look"

ive had a set of 15" cavalier expression wheels in the garage for over a decade so decided these would be my daily wheels (with a set of uniroyal rainsport 5 on them, to serve as "wet" tyres)

heres a couple of photos from refurbishing them myself, it took nearly 2 days to clean and prep them, before unloading serveral tins of ford arizona gold (also known as "brown" to you and me) and clear coat. i think i did 3 colour, 4 clear








youll also notice the car came on a set of white wheels. these are actually period OZ rally route (magnesium) which are too exotic to replace with some cavalier wheels. They were typically only used on astra rally cars, but i have a tenuous link to BTCC as louise aitken-walker used an actual converted rally car in the BTCC for the first 5 rounds...




so i bought some reproduction OZ stickers from a website called highgate house (6 sets) and applied them to the 4 wheels on the car.



and i also had 2 spares which were still in 1990s trim, i had to refurb these before stickering them up correctly

[75swb]

Well this is excellent!

[darrenh]

some transmission porn, this is a GM F20 5 speed casing with quaife straight cut syncro gear kit, and gripper limited slip diff (clutch type). for the statisticians these are the gear ratios. to give an idea how close ratio this is, the drop in revs between gears is approx 1300rpm. large final drive limits the top speed to 138mph @ 8250.

1) 2.540
2) 1.760
3) 1.420
4) 1.190
5) 0.958

4.2 FD.







in june this year i converted from the original gear stick (which was actually a retrofitted vectra item) to a harry hockly motorsport shifter. its almost identical to quaifes and instead of the standard convoluted system of levers and seeswaw joints, its a single straight rod direct from the stick to the selector turret.

[jonsey]

That’s the same set up in my nephew’s Astra, but his is only geared to 100mph

[darrenh]

Aug 29, 2024 19:45:45 GMT jonsey said:

That’s the same set up in my nephew’s Astra, but his is only geared to 100mph

allot of fun driving to northampton in july (50mph = 3000rpm, 70mph=4300 )

[jonsey]

Aug 30, 2024 8:36:44 GMT darrenh said:

Aug 29, 2024 19:45:45 GMT jonsey said:

That’s the same set up in my nephew’s Astra, but his is only geared to 100mph

allot of fun driving to northampton in july (50mph = 3000rpm, 70mph=4300 )

That would get tiring quickly.

[jmsheahan]

Oh yes! Bookmarked, keep the updates coming!

[Sweetpea]

Ah Mr DH. I wondered where you'd got to. Or I could have been inattentive which would be normal for me.
So you kept the Rover of Lands when rightsizing your fleet?

Anyway, jolly good. Bookmarked and all that. Looking forward to seeing how this goes.

James

[mrbig]

This is fantastic!

[darrenh]

Sept 2, 2024 22:07:46 GMT Sweetpea said:

Ah Mr DH. I wondered where you'd got to. Or I could have been inattentive which would be normal for me.
So you kept the Rover of Lands when rightsizing your fleet?

Anyway, jolly good. Bookmarked and all that. Looking forward to seeing how this goes.

James

yeah still have the land rover and the black estate (which ive been daily driving/commuting for 8 years now, puke)

[darrenh]

potted history on the boingy bits.

so its running coilovers on all 4 corners right now. As standard mk2 astra were mac strut front, separate spring and damper rear which presents problems. first is because the rear turret is not load bearing, and second because they werent coilover as standard, theres little to no aftermarket options off the shelf.



this is the "after" photo, the turret is an off the peg item meant for 4 linking mk2 escorts, obviously modified to fit here, the bottom goes right along side the standard chassis rails which is perfect for transferring vertical load into the shell.



gaz have been really supportive of vauxhall world and sell a gaz gold set which are converted front struts, plus modified mk2 escort rear coilovers.... currently its running 300lb front springs and 250 rear. i also have a spare set of 350lbs to play with.



in addition up front the car has group A lower arms. youll find something like this in the historic homologation papers, but in period they only seemed to be used on circuit racers on the continent. most likely this was due to the tyre rubbing on the drag link at full lock (reduced lock on a rally car would be suicide) Anyway, they are harry hockley items but modified for some quality of life to take a standard mk2 astra outer balljoint (as standard they are rose joints)





heres a photo on the car, you can see the chassis is also modified to make the pivot bolt double sheer at the front.

EDIT

i forgot to say, the combo of adjustable bottom arms and the eccentric top mounts it now has 5 degrees of positive caster and 1.5 degrees of negative camber (per side) the standard suspension had 1 degree positive caster on one side, zero on the other, 1 degree negative camber on one side, half a minute on the other. more important the stock suspension would roll into negative caster with suspension compressed (which goes some way to explaining why these have a bad rep for handling, ignoring how ridiculously under-tyred they are)

net result of positive caster (meaning the strut leans towards the back of the car) is that when you steer off dead ahead, it ads a huge dollop of negative camber onto the laden wheel, exactly what we want.

[darrenh]

boiler room !

so, even non vauxhall aficionados will be aware of the famous "red top" or 2.0 twin can 20XE engine. as standard they gave 156PS in pre emissions spec.

deviations from that are 284 / 278 camshafts (made by kent cams, but grind is specific to SBD motorsport) they are basically the most aggressive cam while still being hydraulic lifters, powerful but very much still streatable, depending on the rest of the engine will open the valves high enough and long enough to get 225bhp while still being greater or equal torque to standard over entire rev range.



pistons are forged items from omega, 87mm, which gives it a tad over 50cc extra



steel H beam con rods (pictured next to a standard one)



wind comes out of the other side through an F2 spec 4 into 1. by F2 i mean the FIA group A spec used from 1993 onwards, aka "kitcar", its made by BTB and part of the kit that SBD motorsport homologated back in the day. good enough for just over 300bhp. its pictured next to a standard manifold here. the exhaust system is a 2 silencer in stainless steel of 2.5 inch pipe work, which i had commissioned back in 2005, eeek



on the intake side is a vintage set of jenvey 48mm paralell throttle bodies, with management being taken care of by equally as old MBE ecu (to give you an idea of the age, the interface is paralell port )

ignoring variation between engine dynos it makes 210-220bhp at 7000rpm, 180lbs of torque at 6000, rev limit 8250

[darrenh]

livery prep ! ive been using a company called "isaydingdong" who i originally found just by googling esso british touring car stickers. 75% of what i needed were off the peg items, the others were custom sized versions of what they already sell (like the big MOBIL sign) and the last few bits have been custom custom from scratch (like the long vauxhall for the sides). they have been brilliant to deal with, very patient and would highly recommend.



the tailgate will have GM dealersport colour flashes and mobil logo, which meant the controversial decision to remove the iconic astra GTE black vinyl. this was a complete pain in the fox picture but the method got refined to a paint stripper hot air gun to soften the glue, but not so hot to make the vinyl stretchy. Also had an extra kick in the nads because the car has had a respray up to the edge of the vinyl, which left a hard masking line of paint. i wet sanded the edge very successfully, too successful in some places down to the black primer so ended up respraying the tailgate white.

[sebastiaan]

Isaydingdong are great. Dealt with them in the past for this and can't fault them.

[stealthstylz]

This is epic. Great stuff.

[darrenh]

this took a while! applying the big MOBIL 1 sticker, then masking a couple millimetres around the lettering (so mobil ends up with white outline rather than butting up to the colour stripes). ive yet to refit the tailgate handle



heres a picture of clelands car, ive omitted the spax sticker due to, errr, personal preference (but i realise it was who paid the bills not what the car had fitted)

[darrenh]

ive not really gone into it in much detail but i am one of the admins for the mk2 owners club. i have a bit of a fetish for the motorsport side of it and over the last 5 years have managed to befriend quite a few of the original GM dealersport technicians from back on the 80s and 90s. Some of them who are old enough to be in the industry from as early as dealer opel team, i.e walter rohrl in the opel ascona and kadett C (which was started by a british guy called Tony fall) through the ascona and manta 400, right through MSD period with the mk3 astra and calibra, into ray mallock mk4 astra kit car. anyhoo, over the years i managed to find an official guide to livery-ing the astras, includes the british standard paint codes plus measurements to place the colour stripes (these were sign written back in the day, not vinyls !)

if you look closely at this photo in milton keynes workshop you can see a partially finished bonnet on an artists easel !



the astra BTCC cars were run separately by dave cook race services, and managed by john clelands dad bill cleland ! dave cook also carried on into the cavalier supertouring period with john cleland and jeff allam until the cars were taken over by ray mallock and ecurie ecosse.

the btcc astra gte had a slightly different layout to its WRC cousins, but still on the same theme as the above photo, principle sponsor mobil 1 and vauxhall itself. i'm also using a huge catalogue of old photos to get a pastiche of the 3 cars. The main block colours are on the bonnet and flank, with the same tedious masking round its MOBIL 1 like the back end. its looking very motorsport now, and taking the edge off the wheels.

[jmsheahan]

Epic work, those graphics look amazing! More please!