My 1.8 (z18xe) Corsa C on Jenvey throttle bodies

[MikeITB]

Hi all,

Someone sent me a link to some Corsa C projects on here, certainly a lot more hands on and technically orientated than the forums I'm used to.

Thought I'd take a few minutes to introduce myself and show you my car.

My name's Mike, I live in the South East and I am regional organiser for www.corsa-c.co.uk You can see my entire build thread on that site if you are interested but I won't post all of the details here as there is a mountain! lol

I have a 55 plate Corsa C SRi which I believe to be the first road legal Corsa C on throttle bodies using the standard z18xe engine. Please correct me if I am wrong and show me what other people have done as I would be very interested to see.

Here's the current spec:

Engine Modifications:
1.8 litre (Z18XE) 16-valve
Emerald K3 stand alone engine management
Jenvey 45mm ST tapered throttle bodies
Jenvey fuel rail with -6 fittings
60mm Trumpets
Bosch 440cc/min Injectors
Magnecore 8.5 KV85 Ignition leads
Martin Bowyer inlet manifold
Piper 4 branch (4-1) manifold with 2.5” system –Stainless, sports cat – Backbox = Style D, 3” outwardly rolled
Piper BP270 fast road spec cams
Lightened and balance flywheel
Aluminium oil catch tank
Roose Motorsport red silicone hoses
Richbrook oil filler cap (whoever decided to make it out of metal so that it gets hot needs a slap)
Z20LET coolant rail
Black electrical conduit off eBay
Coolant and washer reservoir caps paint in silver (Hammerite)
Custom made coilpack cover
Factory 5 speed transmission (F17)
16 row Mocal oil cooler with aeroquip lines
(Quaife Limited Slip Diff getting ordered today/tomorrow)

Suspension Modifications:
Koni adjustable coilovers
Whiteline adjustable rear anti roll - 20mm, heavy duty, blade adjustable
Weischer front upper strut brace
Weischer bolt in half roll cage (euro spec)

Wheels, Brakes and Tyres:
Road: 16” Irmscher Signa design with Toyo Proxes T1-R tyres 195/45/16R
Track: 16” Irmscher Softstar design (fluorescent orange) with Goodyear Eagle F1 tyres –6J195/45/16R
280mm VXR front brake set up

Interior Modifications:
Irmscher full leather steering wheel
Irmscher floor matts
White LED conversion– Clocks, MFD, window switches, heater controls
Sparco Sienna bucket seats
Sparco 4 point 3” harnesses
Sparco 3" harness pads
0.8mm thick Carbon fibre rear door cards
Re trimmed roof lining, A,B and C pillars - Plain black for the roof, “Leonardo” pattern for the pillars
Halfords elasticated cargo net
Carbon fibre rear door cards

Exterior Modifications:
Irmscher front splitter
Irmscher head light brows
Irmscher aluminium strip grille (smoothed and re sprayed)
Irmscher B pillar trims
Irmscher side skirts
Opel blitz rear badge
Tinted windows
Astra VXR Nurburg ring edition decals (bonnet, roof and boot)
Bee sting aerial
HID Xenon headlight conversion (8000k)
Colour coded arches (20R Sapphire black)

ICE:
Sony xplod head unit of some description

Security:
Alarm: Factory fitted thatcham category 1

The throttle bodies were fitted by Motech Vehicle Services
The mapping was carried out by Track 'n' Road Powerformance and Race Engine Calibration in Rainham Essex (whom I would highly recommend)

This will be featured in an upcoming issue of Total Vauxhall

And here's a few pictures:











All comments welcome

Thanks

Mike

[peester]

nice , saw at PV and on corsa C forums.. thats 4 t.b'ed z18's or so that i know of.. tho not all in corsa c's..
good stuff, running good now??

[MikeITB]

nice , saw at PV and on corsa C forums.. thats 4 t.b'ed z18's or so that i know of.. tho not all in corsa c's..
good stuff, running good now??

Thanks, yup was just there for soggy Sunday, lol.

what others do you know of? I'd be interested to see what other people have done and see what kinda of power they're running. Got any links?

Yes, running perfectly now, had trouble with the standard coilback but x20xev coilpack and leads along with a final mapping from Steve sorted that out Love it now, puts a huge grin on my face

[peester]

cool, i bet it goes and sounds awesome mate. Im deffo a fan of the z18, the 'new c20xe' itll be. lol.
Others?
well of who i know of, lee303 of course is the man, tho technically his started out originally the x18xe1 (same as z18 but not flyby)

boooom 230bhp.
I think its based on a rallycross-winning bowyer engine which was the first we saw of a z18xe on t.b's..

then theres Warren G, im sure you know of his corsa b..?
and then theres me lol..tho im not quite there yet. Also in a nova, but merely std spec z18xe at the mo tho.

[MikeITB]

Cheers dude, yeah it goes lovely now it's all sorted, upsets a lot of "bigger" cars. Only had it out on the track once so far but have 3 shows with track time or track days lined up for september. And the noise!! Almost worth all the money in itself, lol

Well for me the z18xe was the clear choice, I wanted a new engine (so not an old redtop) and something that was still lightweight to keep the car balanced. A hell of a lot of people are going for c20lets which will be good for straight line speed but would get trounced in the corners. It also helped that my car came with it as standard, lol

Aaahhhh yes, I've heard much about "Lee's Garage" lol. Steve Greenald does work for him I believe, the same guy who mapped my car. And yes I discounted that one as it's an X18XE1, lol. Still essentially the same I know, I think the cams are slightly different but my best guess is that he's chanegd those so essentially yeah it's the same.

Martin Bowyer, thoroughly nice guy. He provided me with a hell of a lot of information for my build and I bought my inlet manifold from him. I envy the amount of space you Nova boys have in the bay.

As for Warren! Yes i know him very well indeed. So far he's fitted my lightened flywheel, 280 VXR brake set up, tidied the wiring in my engine bay and sourced me many more things. He'll be fitting my Quaife too. His project started as a z18xe but due to some potentially dodgy pistons it met a sticky end. He's now running an x18xe1 also.

Interested to see what you've got going there, do you have a build thread or any further details on what you're doing? What throttle bodies are you using? What are your plans with the coilpack? I spy a standard one and I couldn't recommend enough that you should ditch in favour of a set up with leads! Mine are from an x20xev

[DaveB]

Lovely corsa, nice wheel colour too Similar to mine

What power have you got from the engine, I couldn't see you mention it anywhere

[MikeITB]

Lovely corsa, nice wheel colour too Similar to mine

What power have you got from the engine, I couldn't see you mention it anywhere

Thanks They're just for track use but get a lot of attention, lol. What have you got?

XE on TB's? What XE would that be? C20?

I didn't mention it anywhere... :P lol. The reason being too many people talk pub figures and wright the car off as a failure when I say it's 160.9 bhp. That was measured with roughly an 8.5% transmission loss. If it was calculated at the 22% (Like Regal) it would be more like 180bhp

When I get a minute I'll scan in the 3 RR graphs I have, 2 pre ITB's and one post, you can see from that the massive difference it's made to how the power is delivered (I'm sure you're probably already aware of this with yours)

It may interest some of you to know, if you don't already that Wossener/PEC are releasing z18xe rods and pistons by the end of August, both high comp and low comp.

Lots more planned to drive the power up

[DaveB]

Mines a C20XE yes I've got a thread on here in the project/resto section, it's about 6 posts down at the moment, make a brew lmao

Mine's at 207bhp@7500rpm iirc. There's a graph somewhere on my thread, Noble Motorsport mapped mine. I love the power delivery, it just revs and pulls and revs and pulls No lag ftw

[MikeITB]

Mines a C20XE yes I've got a thread on here in the project/resto section, it's about 6 posts down at the moment, make a brew lmao

Mine's at 207bhp@7500rpm iirc. There's a graph somewhere on my thread, Noble Motorsport mapped mine. I love the power delivery, it just revs and pulls and revs and pulls No lag ftw

Ah cool, I'll have a look in there. Must be a lot of fun

I'll drink to that lol

[lee303]

160 bhp on a near stock engine is a good result i reckon, especially on an accurate rolling road, any torque figures? did you have to pocket the pistons at all?ther doesnt appear to be much room in a stock engine for a big cam upgrade, oh and at what sort of revs was that, sorry for being noseylmao
steve G does indeed map my car, and martin is a nice bloke too, just a bit slow with parts sometimes! i think the 1800 will be popular, but i doubt it will ever get to the level of the 1600 as far as parts availability goes as its juts not used as much in motorsport, shame really

[MikeITB]

160 bhp on a near stock engine is a good result i reckon, especially on an accurate rolling road, any torque figures? did you have to pocket the pistons at all?ther doesnt appear to be much room in a stock engine for a big cam upgrade, oh and at what sort of revs was that, sorry for being noseylmao
steve G does indeed map my car, and martin is a nice bloke too, just a bit slow with parts sometimes! i think the 1800 will be popular, but i doubt it will ever get to the level of the 1600 as far as parts availability goes as its juts not used as much in motorsport, shame really

Cheers, I like to think it's pretty good, certainly drives very well. I think if anyone else called my engine "near stock" I may be offended but not coming from you lmao

No pockets on the pistons as they're only very mild cams currently, fast road cams reprofiled from standard z18xe cams.

Rev limiter is currently set at 7500 and the peak bhp was more or less there.

Torque is only around 125ft/llbs iirc which is a bit of a let down, I think they're about that standard, lol.

Please, be as nosey as you like, it's nice to talk to someone with a similar (although much more advanced) set up.

Very true with Martin lmao, certainly needs the odd toe up his backside but charges very little and gives plenty of advice.

I already have a spare cylinder head that's going to be flowed to see what can be got out of it, then I'll be getting some custom cams with vernier pulleys, forged rods, bolts and high comp pistons. Will be a while before that though as I've got the Quaife and fitting to pay for.

It is a shame in a way with the 1800 not being used as much but at the same time makes those of us that have them that little bit more special. Having a lot of similar componenets to the 1600 helps

[lee303]

didnt mean to offendlmao
anyways, the head is pretty bloody good as stock tbh, the ports are massive, and so, much like duratecs, they tend to like cams with les duration but more lift, i only have 288s in mine, but the lift is pretty extreme, does require solid lifters to cope with the ramps angles though
what you really want for more power is more compression and room for some decent cams, in other words pistons! its a bit tricky to do though due to the pin height on the readily available 1600 omegas or similar being totally wrong for the 1800, i went for some lovely 2 ring beam type slipper things from SBD that were made for steves 1700 but they required longer rods to get the compression, and then it starts to get expensive!!
martin can supply all you would want though, he has built a few now so has the patterns for the rods etc
you'll probably want to talk to him about the valves too, as they tend to break at the collet grooves as they are so skinny, he does some modified ones with a different collet setup that removes the problem, not a cheap engine, but certainly the best i've ever had

[pas-chill]

Good stuff, Mike.

[peester]

Interested to see what you've got going there, do you have a build thread or any further details on what you're doing? What throttle bodies are you using? What are your plans with the coilpack? I spy a standard one and I couldn't recommend enough that you should ditch in favour of a set up with leads! Mine are from an x20xev

i do have a build thread..
http://www.pngclub.com/forum/showthread.php?t=82994
quite an epic thread now tho as its steady progress for over two years, but its page 38 onwards for the z18xe conversion.
Im basically, for the time being at least, running a standard z18xe on t.b's and mbe all from bowyer. Ive got the same piper ex.manifold as you. (non cat?)
T.b's are jenvey parrallel twin 45's.
The coilpack, along with everything else thats missing is a compromise mostly, didnt have £££'s.. bowyer ok'd it - my mbe loom runs a couple of extra 'amplifiers' to connect to the coilpack directly.
I am proper skint now tho, its gone quite out of hand, way over what was planned..
Im not too arsed about power torque or anything at this stage, just want it finished lol. Last time i drove it, it was a 90bhp stripped out nova, so im sure the t.b'd z18 will do me for now at least.

[cambridge]

8.5% loss, thats pretty damn good.... some wouldnt believe that but it was done at TnR so its good enough for me my plastic skip managed nearly 22% peak loss there lol

[MikeITB]

didnt mean to offendlmao
anyways, the head is pretty bloody good as stock tbh, the ports are massive, and so, much like duratecs, they tend to like cams with les duration but more lift, i only have 288s in mine, but the lift is pretty extreme, does require solid lifters to cope with the ramps angles though
what you really want for more power is more compression and room for some decent cams, in other words pistons! its a bit tricky to do though due to the pin height on the readily available 1600 omegas or similar being totally wrong for the 1800, i went for some lovely 2 ring beam type slipper things from SBD that were made for steves 1700 but they required longer rods to get the compression, and then it starts to get expensive!!
martin can supply all you would want though, he has built a few now so has the patterns for the rods etc
you'll probably want to talk to him about the valves too, as they tend to break at the collet grooves as they are so skinny, he does some modified ones with a different collet setup that removes the problem, not a cheap engine, but certainly the best i've ever had

Hey no worries at all. Just going from the forum I'm normally on it's strange, most people there are 17/18 and have a backbox and a panel filter, lol, but this is where the bigger boys play lol.

Yeah I've heard a lot of people say that about the CH already being very good as stock and I was just talking to Pascal the other day about more lift being of great benefit on Sunday. None of the high comp rebuild will happen until at least next year anyway so I've got plenty of time to research and think about all the hows

I'm sure I'll be back in touch with Martin when I'm gearing up for the next stage, shame he's so far away from me as I'd love to go and meet him and have a good look around some of the cars/engines he's built.

It's ok, I understand there's a fairly hefty cost with these things, I've been through plenty already but it's all worth it. I'm only young once so going to enjoy spending money while I can

Good stuff, Mike.

Cheers Pascal

i do have a build thread..
http://www.pngclub.com/forum/showthread.php?t=82994
quite an epic thread now tho as its steady progress for over two years, but its page 38 onwards for the z18xe conversion.
Im basically, for the time being at least, running a standard z18xe on t.b's and mbe all from bowyer. Ive got the same piper ex.manifold as you. (non cat?)
T.b's are jenvey parrallel twin 45's.
The coilpack, along with everything else thats missing is a compromise mostly, didnt have £££'s.. bowyer ok'd it - my mbe loom runs a couple of extra 'amplifiers' to connect to the coilpack directly.
I am proper skint now tho, its gone quite out of hand, way over what was planned..
Im not too arsed about power torque or anything at this stage, just want it finished lol. Last time i drove it, it was a 90bhp stripped out nova, so im sure the t.b'd z18 will do me for now at least.

Great, I'll have a good look through when I get the time to give it some attention, I'm sure I'll find it interesting.

My system has a sports cat but can be easily removed for a decat, soemthing I'm considering doing at the moment, do you know if that will make the system any louder though? I may keep both for road/track use.

Ahh I see, sounds like you've got it covered then. I'd just hate for someone else to go through all the same headache as I did due to those dodgy mass produced pieces of cack!

Will definitely be a big difference, I'm sure you'll be pleased with the results. Especially being in a Nova you'll be flying, lol.

8.5% loss, thats pretty damn good.... some wouldnt believe that but it was done at TnR so its good enough for me my plastic skip managed nearly 22% peak loss there lol

I'll admit that was abit of a guess based on poor memory on my part, I double check my graph last night and it's actually around a 13% transmission loss which still isn't bad

[MikeITB]

Also, mainly for peester/Lee, I've just polished up a spare rocker cover and a friend of mine made me a coilpack cover, if either of you are interested in a custom coilpack cover let me know, they're only cheap and can be completely custom. She has all of the measurements to fit directly to the cam cover or to a coilpack



I can't wait to get it fitted

[lee303]

looks nice i already have a custom cam cover with all the breather chamber removed and welded up with a flat plate and made my own plug cover out of stainless, which sits level with the new lower line of the camcover, dave(peester) may be interested though

[MikeITB]

looks nice i already have a custom cam cover with all the breather chamber removed and welded up with a flat plate and made my own plug cover out of stainless, which sits level with the new lower line of the camcover, dave(peester) may be interested though

Is your breather just blanked off then? Or repositioned? The one pictured is currently with JDT getting the existing breathers blanked off and having a new one on the far left of the rocker cover close to where I've mounted my catch tank.

It was only the coilpack cover I can put people onto though, I just wanted to show off my DIY polishing skills, lol

I've just read through Peester's thread from page 38 onwards, made for some interesting reading, especially where MR Bowyer is concerned.

Do you have a full spec list of your car anywhere? I have briefly ventured into your thread but reading that is like the thread equivelent of Mt. Everest, lol.

[Gary_808]

i'm in the process of building sadly i've had my inlet on order for 2 months now apprently it's machined but he's dissappeared

[MikeITB]

i'm in the process of building sadly i've had my inlet on order for 2 months now apprently it's machined but he's dissappeared

Ouch! I think I must have been a mixture of lucky and persistent, I managed to get mine done within a few weeks and that was with him adding an alternator bracket mounting point. He is a really nice guy though, just a shame he has absolutely no sense of urgency lmao

Hopefully you'll get it soon mate, keep your chin up, will be worth it in the end. Do what Peester did and use the time well by polishing/painting etc...

[lee303]

Is your breather just blanked off then? Or repositioned? The one pictured is currently with JDT getting the existing breathers blanked off and having a new one on the far left of the rocker cover close to where I've mounted my catch tank.

i have all my breathers blocked as i run a dry sump, on the old 1600 i had the smaller one on the cam cover blanked off and the larger one to a catch tank, seemed to work well enough but did breathe alot at high revs

Do you have a full spec list of your car anywhere? I have briefly ventured into your thread but reading that is like the thread equivelent of Mt. Everest, lol.

i can do a spec, bare with me if its a bit long windedlmao

Engine:
x18xe1 block bored to 82mm
Omega beam type 2 ring slipper pistons, with coated skirts
custom farndon rods, 3mm longer than stock with smaller little end to suit piston pins
double doweled steel billet ultra light flywheel(2.9KG) with 7.25'' helix solid single cerametallic paddle clutch to suit, red spring rating
lightened and balanced bottom end by vibration free
catcams 288s solid profile with lots of lift(cant remember exact figures but can look them up if you need) balanced SBD vernier pullies
solid lifters
custom 5mm stem valves, standard size but modified collet arrangement
copper berillium valve guides
gold double valve springs
jenvey 45mm parallel throttle bodies with 90mm trumpets
bowyer inlet manifold
home ported head with de shrouding work to the inlet valves and matched chamber volumes, skimed to get required compression ratio and squish
Simpson racing full exhaust manifold and one box system
pace dry sump kit custom mounted on the water pump side of the engine with modified scavenge outlets to use JIC fittings
pace dry sump tank
davies Craig electric water pump with stok pump deleted form cambelt run
custom cambelt tensioner to suit
13 row thermostatic mocal oil cooler
magnecor leads
vectra coil pack
aero systems fuel pressure regulator
peco yellow band fuel injectors @ 4 bar
sierra cosworth fuel pump with facet lift pump feeding 1.5 ltr swirl pot

Transmission:
Hewland 6 speed straight cut dog box with Formula 3 plate diff
custom driveshafts to suit inner cvs
quaife gear lever with custom linkage

Suspension:
home made rose jointed adjustable front tie bars
front ARB removed
Gaz coilovers all round with turreted rear arches and reinforced lower mount to suit
eccentric top mounts
rose jointed TCAs
quaife quick rack, 2.2 lock to lock

rest of the car is pretty obvious, custom seat position, Tilton pedal box with brake bias adjustment, lightweight panels including carbon fibre doors, plastic boot and bonnet and plastic windows, aim dash in carbon binnacle, 15'' compomotive th2s with yoko A048r tyres, corbeau seats, safety devices roll cage, 300mm front dics with willwood calipers, stock rear drums, carbon roof vent, heated front screen, plumbed in fire extinguisher

as i say, bit long winded, but i think thats it!

[MikeITB]

i have all my breathers blocked as i run a dry sump, on the old 1600 i had the smaller one on the cam cover blanked off and the larger one to a catch tank, seemed to work well enough but did breathe alot at high revs


i can do a spec, bare with me if its a bit long windedlmao

Engine:
x18xe1 block bored to 82mm
Omega beam type 2 ring slipper pistons, with coated skirts
custom farndon rods, 3mm longer than stock with smaller little end to suit piston pins
double doweled steel billet ultra light flywheel(2.9KG) with 7.25'' helix solid single cerametallic paddle clutch to suit, red spring rating
lightened and balanced bottom end by vibration free
catcams 288s solid profile with lots of lift(cant remember exact figures but can look them up if you need) balanced SBD vernier pullies
solid lifters
custom 5mm stem valves, standard size but modified collet arrangement
copper berillium valve guides
gold double valve springs
jenvey 45mm parallel throttle bodies with 90mm trumpets
bowyer inlet manifold
home ported head with de shrouding work to the inlet valves and matched chamber volumes, skimed to get required compression ratio and squish
Simpson racing full exhaust manifold and one box system
pace dry sump kit custom mounted on the water pump side of the engine with modified scavenge outlets to use JIC fittings
pace dry sump tank
davies Craig electric water pump with stok pump deleted form cambelt run
custom cambelt tensioner to suit
13 row thermostatic mocal oil cooler
magnecor leads
vectra coil pack
aero systems fuel pressure regulator
peco yellow band fuel injectors @ 4 bar
sierra cosworth fuel pump with facet lift pump feeding 1.5 ltr swirl pot

Transmission:
Hewland 6 speed straight cut dog box with Formula 3 plate diff
custom driveshafts to suit inner cvs
quaife gear lever with custom linkage

Suspension:
home made rose jointed adjustable front tie bars
front ARB removed
Gaz coilovers all round with turreted rear arches and reinforced lower mount to suit
eccentric top mounts
rose jointed TCAs
quaife quick rack, 2.2 lock to lock

rest of the car is pretty obvious, custom seat position, Tilton pedal box with brake bias adjustment, lightweight panels including carbon fibre doors, plastic boot and bonnet and plastic windows, aim dash in carbon binnacle, 15'' compomotive th2s with yoko A048r tyres, corbeau seats, safety devices roll cage, 300mm front dics with willwood calipers, stock rear drums, carbon roof vent, heated front screen, plumbed in fire extinguisher

as i say, bit long winded, but i think thats it!

Yeah mine seems to breath a hell of a lot, I'm glad you've said that as now I think it must be normal, lol

Wow, that's one hell of a spec list, thanks for taking the time to type it up. It reminds me of collecting football stickers at school thinking "got, got, need, need, got, need, need, need" lmao Gives me a good idea of the work involved in getting the power out of it, looks like I've got a long way to go, lol

[lee303]

the small blocks tend to suffer from oil retention in the head and the cam box at high revs, which means the breathers get more oil than vapour, hence the apparent heavy breathing, it can lead to the crank getting a bit starved of oil too, there is a fix, you need a seperator system that seperates the oil from the vapour and returns it to the crank case, pro tec do a very expensive kit, but you could make something yourself fairly easily, dry sump is the other(expensive) option ofcourselmao

and no worries on the spec, had to edit it a few times as i kept forgetting stuff lmao

[MikeITB]

the small blocks tend to suffer from oil retention in the head and the cam box at high revs, which means the breathers get more oil than vapour, hence the apparent heavy breathing, it can lead to the crank getting a bit starved of oil too, there is a fix, you need a seperator system that seperates the oil from the vapour and returns it to the crank case, pro tec do a very expensive kit, but you could make something yourself fairly easily, dry sump is the other(expensive) option ofcourselmao

and no worries on the spec, had to edit it a few times as i kept forgetting stuff lmao

Ahhh I see. I'd LOVE a dry sump but like you say, lots of money

I know what you mean, I had to type up a spec list for the magazine feature and when I thought it was 100% finished I sent it to a mate to proof and he added about 4 or 5 things still, lol