Astra VXR (Z20LEH) engine conversion into my Corsa VXR Racing
As of October 2010 the power/torque output from my Corsa was 255.2bhp @ 6335rpm and 280.75ftlb @ 3415rpm.
My quest to achieve 300+ bhp led to more discussions with Thorney Motorsport as to my options.
Sticking with the Corsa VXR Racing engine (Z16LER) would require a bottom end and turbo upgrade, all possible but resulting in a more highly stressed engine.
Another option, proposed by Thorney Motorsport, would be to replace the Corsa VXR engine (Z16LER) with the Astra VXR engine (Z20LEH). With the mods already carried out my car - larger front mounted intercooler and 3" stainless steel race exhaust power/torque figures of 300bhp/340ftlbs would be immediately available from the Astra VXR engine (with a suitable remap) in it's standard specification.
Also, already having the Quaife LSD and AP Racing Brakes fitted will ensure that all this extra power can be safely handled on both the road and track.
However, the exciting part of this option is that by further modifying the Astra VXR engine (upgraded turbo - GT28, equal length exhaust manifold, uprated pistons & rods and uprated injectors) it will be possible to achieve at least 380+ bhp.
So, this is the route I have decided to follow - the brand new Astra VXR engine is on order from Opel - work will start in October and take about 2 months.
I will document the progress of this exciting project on this page with updates and photographs.
August 10th 2011 - Updates moved to new website
A new website www.corsaracecar.co.uk has been created to document the development of the Corsa SRI race car purchased from Thorney Motorsport. To follow the progress of the Astra VXR engine conversion into this Corsa SRI click here. No further updates will be posted here on this Corsa VXR Racing website.
June 24th 2011 - Sachs clutch, lightened flywheel
Sachs clutch and lightened/balanced stock dual mass flywheel now fitted. At this stage TMS are not convinced a single mass lightweight flywheel won't suffer with resonance and vibration transfer from the engine. Further development work will continue in this area so for now we'll be sticking with the lightened and balanced OEM dual mass flywheel.
June 20th 2011 - Sachs clutch, lightened flywheel, ceramic coating, rigid pipes ...
Hopefully this week the Sachs organic clutch, lightened and balanced stock flywheel together with a brand new gearbox/Quaife LSD should be fitted. The rigid intercooler pipes are promised in this week. The tubular exhaust manifold, turbo housing and exhaust downpipe are all going off to Zircotec to be ceramic coated - metallic black
Things are moving forward very slowly but surely. More updates are due later this week together with photos.
May 25th 2011 - ECU integration, Astra VXR throttle body ...
Work is ongoing integrating various aspects of the Corsa and Astra VXR ECU's so as to ensure both the engine management side of things together with ABS, traction control, power steering are all "talking" to each other. Still some work to be done on the Astra VXR throttle body to ensure it will physically fit. No sign yet of the rigid stainless steel intercooler pipes - promised very soon. Sachs clutch and lightened flywheel together with the brand new gearbox/Quaife LSD diff still to be fitted.
April 27th 2011 - Intercooler pipework
The new alloy radiator and intercooler have been fitted. Metal pipework for the intercooler are to be manufactured (rather than using silicon hoses). Alternator custom mounting bracket now made up and fitted as well as the final design of engine mounts.
April 18th 2011 - New radiator and intercooler
At last the new, uprated all aluminium radiator and intercooler has arrived - some 2 weeks late on delivery! It seems that delivery promises mean nothing within the motorsport manufacturing industry. Anyhow, the dry fit is continuing apace and nearing completion. Once all the final bits and pieces are in place attention will turn to the ECU and wiring loom. Then it's onto the rolling road and remapping.
More photos of the radiator and intercooloer are available to see in the engine conversion photo gallery.
March 18th 2011 - Uprated clutch
TMS recommend to use a Sachs Organic Clutch Kit together with the stock flywheel. Sachs Performance clutches offer extended life spans and superior thermal resistance. At this stage TMS are not convinced a single mass lightweight flywheel won't suffer with resonance and vibration transfer from the engine. Further development work will continue in this area so for now we'll be sticking with the OEM Dual Mass Flywheel. The Sachs clutch cover, matched to a rigid organic drive plate, which gives a virtual OEM pedal response is rated at 407 lb/ft torque when used in combination with this up-rated organic drive plate.
March 16th 2011 - New radiator and intercooler
Unforseen delays means the new radiator and intercooler are still awaited. They are now due by the end of the month. Apart from these two items the dry engine installation is all but complete. The next stage will be to fit an uprated clutch to ensure the power can be reliably transmitted down to the wheels and then it's onwards to the remapping and rolling road!
More pictures to follow soon.
February 8th 2011 - New radiator and intercooler
To ensure maximum cooling capability it has been decided to fabricate a brand new aluminium radiator and intercooler. Being of all aluminium construction will ensure maximum reliabilty and cooling capability as well as avoiding the well know problems associated with the aluminium/plastic construction of the standard Corsa VXR radiator. Cold air intake and filtration for the intercooler will be located down behind the front bumper thus maximising air flow and temperature gains as well as reducing air flow path and restriction.
More photographs are available to view.
February 3rd 2011 - Good progress made
Having decided to purchase the TMS Corsa race car the Astra VXR engine conversion is progressing well. The engine/gearbox has been fitted successfully without any major problems. Some mods were required to engine/gearbox/diff mounts. Driveshafts line up ok. Next stage is to check out intercooler and air intake system to ensure there are no heat issues when running 400+bhp!
January 25th 2011 - Latest photographs
New photos are available to view showing the Astra VXR engine fitted into the Corsa race car. Good progress is being made with the dry fit - the only slight difficulty is the diff mounts which are currently being sorted.
January 6th 2011 - Fabrication of engine mounts - engine fit
Due to the heavy snow conditions just before Christmas the dry engine fit into the TMS race car was delayed. The good news is it's ongoing as we speak. Results and photos to follow.
December 21st 2010 - Stage 5 engine power figures from TMS
Thorney have released the engine performance figures for the stage 5 Astra VXR engine. Max power is up to around 375bhp @ 5880rpm with 360ftlb torque kicking in at 3780rpm. I'm still confident that with my stage 5 engine spec - uprated internals and injectors etc. - 400bhp+ is achievable!
December 15th 2010 - Fabrication of engine mounts - engine fit
The engine fit, setup and testing is to be done initially in the TMS race car. This work will start with the engine mount fabrication and engine fit w/c 20 December and should be completed by end of December. The exhaust manifold and turbo housing will be sent of to Zircotec next week to be ceramic coated. The exhaust downpipe will follow, once it has been fabricated to match up with the exisiting stainless steel exhaust system.
November 30th 2010 - Latest stage 4 engine power figures from TMS
Thorney have managed to squeeze extra bhp out of the stage 4 Astra VXR engine. Max power is up to around 350bhp this with standard internals and injectors. With my stage 5 engine spec - uprated internals and injectors - I'm hoping TMS will get 400bhp+. Confirmation from Thorney eagerly awaited!!
November 24th 2010 - Ceramic coating of exhaust, turbo housing
Primarily to benefit engine bay cooling but also for visual effect I have decided to ask TMS to arrange to have a metallic black ceramic coating applied to the tubular exhaust mainfold, turbo housing and exhaust downpipe. We have approached Zircotec to carry out the ceramic coating. I have chosen to have the metallic black coating which I think will compliment and enhance the engine bay appearance. Pictures to follow.
November 19th 2010 - TMS webpage
Thorney Motorsports (TMS) have created a new webpage on their website to cover this project. To visit this webpage click here or use the button link above.
November 8th 2010 - Engine rebuild complete
The Astra VXR engine rebuild to stage 5 (380+ bhp) is complete. The next stage is to carry out a dry run for the engine installation into the TMS Corsa race car chassis to enable engine mounts etc. to be postioned ready for fabrication. This will take place this week.
Pictures of the stage 5 Z20LEH engine build to follow.
October 25th 2010 - Engine rebuild
The first stage of this project entails rebuilding the brand new Z20LEH engine to TMS Stage 5 specification (380+bhp).
Basically this involves fitting the following:
- Garrett TMS GT28 Turbo (features Roller Bearings, Uprated Seals and Shafts)
- TMS forged lightweight pistons & conrods
- Bosch 650cc Injectors
- TMS equal length exhaust manifold
- TMS Oil Feed & Breather Pipes
- Uprated manifold studs
- Extra heat shielding
- New boost sensor
- All New Gaskets
The work should take about 2 weeks to complete.
