Opel Kadett GSi Group A Rally Replica

[ant0ny]

Spanktastic.


Clearly going the whole hog with this ones, love to see stuff like this being done, nice work m8.

Yeah after the cams next week I will be getting CW&P made for the 6speed Getrag gearbox to go in early next year.

[ant0ny]

Before xmas I dynod the motor.

Didn't go to plan.

We found that the 272 deg cams are either not 272 deg or we where expecting more from them. Yes the engine did rev more but we made less peak HP.

The manifold also worked fine but the gain was different than expected. It was obvious from the start the engine was more responsive and reved free to and past 7500rpm.

The vernier cam wheels and the standard cams where only 3hp down on the supposed 272deg cams so in the end we ended up with standard cams with the vernier cam wheels and the Lexmal manifold to get a peak power of 140Hp at the wheels.

After putting the engine specs through the engine build software Greame discovered that the standard exhaust was the main problem... we did expect this but underestimated by how much.

More interesting was the inlet manifold design... we discovered that the Lexmal runners where 11" long... if we reduced this to between 8 - 9" long we get a massive increase in power.

So I will make a set of extractors and most likely 4 to 1 and I will make a new inlet manifold but with shorter runners... I don't have the balls to cut up the Lexmal manifold.

end result is the car is faster but 10HP down on the old setup... now there are a few factors...

1: the standard manifold was ceramic coated and this seems to be worth a few HP

2: I ran different tyres 195 65 15s instad of the 50 series slicks from last time.. this may soke up a few HP

3: I was running a very heavy engine oil... this I did at the Autocross when I had that smoky oil problem but was oil sucked into the manifold from the tappet cover.

The engine revs to and past 7500rpm very easily now so I have picked up 20+ kms of wheel speed at peak power so before from a standing start I was struggling to hit 145km/h with the 4.8:1 diff but now I did over 160km/h+ over the same distance roughly.

So on the weekend I built the new extractor as per Greame's engine building software.

4 to 1 extractors with 26inch primary runners @ 1 1/2... then 2 1/4 main pipe 40inches + to 1st muffler.

Flexjoint 2 1/2 shortest one with mesh inner lined.









When I get this finished I will send them to be Ceramic Coated.

[nexia182]

wanna one of those

[MMamdouh]

so you used a 4-1 header setup and that is the same setup as the OEM header... right?

what are the expected gains here compared to a 4-2-1 setup that you could have used?

also the engine mount seems different... are those some aftermarket, more stiff mounts?

MMamdouh

[ant0ny]

so you used a 4-1 header setup and that is the same setup as the OEM header... right?

what are the expected gains here compared to a 4-2-1 setup that you could have used?

also the engine mount seems different... are those some aftermarket, more stiff mounts?

MMamdouh

Different from standard being 4to1 and larger pipes. The length of the 4 primary pipes is the main trick here, they are a tuned length worked out by the flow of the head etc.

Quote: "There are two basic types of exhaust manifolds the 4>1 and 4>2>1. The 4>1 manifold is traditionally used on an out & out racing engine. This is because they work well at higher RPM but they are not very good at low of mid range RPM. The 4>2>1 manifold normally works better in the lower & mid range RPM areas but is not as good at higher RPM."

This explains it better than I could... from this website. http://www.sbdev.co.uk/Main.htm

Engine mounts are billet Aluminium with solid rubber centre so almost solid. Typical mounts for a Rally car and used on Track cars as well.

You can find them here http://www.tjmotorsport.co.uk/products.php?cat=912

[ant0ny]

Been very busy of late... but hasn't stopped progress.

I have Ceramic Coated the exhaust manifold and fitted a new 2 1/4' system to the rear with just 1 muffler and a high flow cat.

I am currently building a new inlet manifold 6 " long runners as per Greame's engine building software and will be heading down to the dyno in a few weeks to work out which manifold is the best between the 11" Lexmal manifold and the 6" manifold... also try the combination of the 272deg cams and standard.

I hope to get the 6spd F28 box appart to order a new crown wheel and pinion to be made to spec... most likly 4:7 to 1 ratio or what ever gets me 200km/h in 6th @ 7000rpm with 15" rims.. I'll need to run that through the software as well.

[nexia182]

niceee!!! love ur kadett e

[ant0ny]

I built the new inlet manifold. It ended up 7inch instead of 6inch because I ran out of time to build a new fuel rail to make it all fit.

inlet_manifold.jpg

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I was very happy with the trumpets

inlet_manifold_2.jpg

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inlet_manifold_3.jpg

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Should do the trick.

Ended up getting 155Hp @ the wheels (ran out of dyno time) but the improvements where more in the power delivery. It as has a long power curve and pulls through to 7600rpm now. Just a reminder that this engine is still stock and stock flywheel that has done 180K+ kms and never apart.

I'll post the dyno sheets soon with the comparison from standard to Lexmal to new inlet manifold etc.

[Big Jeff]

nice work mate

[ant0ny]

Thanks mate.

Manifold fitted





This week end I relocated the battery to make way for the new air box that now will be on the passenger side with the new inlet manifold setup.



Battery is now behind the passenger seat.





You can see I am using the roll cage to make sure I get a good earth through the car. In the engine bay I also taped a thread and connected the negative cable (that used to go to the battery) to the roll cage.

[Big Jeff]

i hope that fuild is not exposive

[wolfsreign]

i trust you know what you are doing but that battery doesnt look like it should be laying down....? why not a optima red top? (maybe weight issues?)

but thats a sick car and setup. awesome. best of luck on the races
~wolf

[ant0ny]

The Battery is a AGM Sealed Battery.


Introducing AGM Batteries
AGM (Absorbed Glass Matt) technology is the next step in the evolution of both starting and deep cycle batteries for all types of applications. This ‘next generation’ technology delivers increased safety, performance and service life over all existing sealed batteries.

• Sealed and Maintenance-Free
• Fully compliant with Sealed Battery Requirements for ships, boats and yachts
• Excellent CCA

According to the rep you can turn it upside down and it wont spill... if you punch a hole in the side it wont leak.

[ant0ny]

I just spent the money I had put away on more HP in the Opel.

WOSSNER 87mm High Comp (12.5:1) Forged Pistons



QED Race Double Valve Springs



TOGA Steel Rods with ARP 2000 Rod Bolts
WISECO MLS headgaske
ARP Main Stud Kit



Plus I have a Uprated Oil Pump coming from Regal Motorsport in the UK. It has the cintered metal pump gear replaced with a steel one and a nylon relief valve.

I have ordered full gasket set from ebay company Gaskets for Classics and I got a new Cam Belt Kit with the tesioner and idler pulley from Vauxhall Parts Warehouse.

All I need is big end bearing and to pull the donk out and build it.

[mr_g]

Love your custom inlet manifold.