Supercharged AJP8. one last step!
Discussion
Its been a project now for 18months but at long last I will find out if fitting a supercharger is a worthwhile method on increasing power on an AJP8 4.5. To be honest if I knew how much hassle it was going to have been then I would have never started as they are not exactly an underpowered car to start with.
As my son said "you are a complete knob with your cars why dont you leave them alone, its fast enough", well that was a challenge in itself so off I went.
After several aborted and costly starts with different inlet cofigurations including a 4.2inlet manifolds and Mustang throttle bodies I have arrived at my present setup which is the 4.5 setup but with the butterflys moved to above the injectors.
I stripped and rebuilt the engine including new undersize liners, gas flowed and ported heads with balanced and matched chambers, total seal rings, new guides, race bearings, complete assembly dynamically balanced. Raceprooved flywheel and slave cylinder new AP clutch,new chains, ACT manifolds and water pipes.
The supercharger is a Vortech V2 SQ hopefully running about 8psi of boost. The injectors are sized at 470cc and are fed from a Bosch 044 race fuel pump.
The engine is running an Emerald ECU with a map sensor and wideband Lamda sensor.
The system just needs mapping,it does run and appears to produce serious accelleration so its off to Emerald on the 28th Feb to let Dave Walker map the system. I let you know what happens. I just hope its all been worthwhile.
I can stick up some more pictures if anyones interested in the project.
As my son said "you are a complete knob with your cars why dont you leave them alone, its fast enough", well that was a challenge in itself so off I went.
After several aborted and costly starts with different inlet cofigurations including a 4.2inlet manifolds and Mustang throttle bodies I have arrived at my present setup which is the 4.5 setup but with the butterflys moved to above the injectors.
I stripped and rebuilt the engine including new undersize liners, gas flowed and ported heads with balanced and matched chambers, total seal rings, new guides, race bearings, complete assembly dynamically balanced. Raceprooved flywheel and slave cylinder new AP clutch,new chains, ACT manifolds and water pipes.
The supercharger is a Vortech V2 SQ hopefully running about 8psi of boost. The injectors are sized at 470cc and are fed from a Bosch 044 race fuel pump.
The engine is running an Emerald ECU with a map sensor and wideband Lamda sensor.
The system just needs mapping,it does run and appears to produce serious accelleration so its off to Emerald on the 28th Feb to let Dave Walker map the system. I let you know what happens. I just hope its all been worthwhile.
I can stick up some more pictures if anyones interested in the project.
These are the modified throttle bodies. The use the original butterflys and shafts, The throttle linkage is a modified jenvey system for a V8.
This was the supercharger bracket. I got this lazer cut and welded together by a specialist to my design. I needed to make some spacers up to get the pulleys to run true.
This was the first attempt at an inlet plenum, I ran the engine last summer with this on without the supercharger, joolz mapped this set up with the MBE and it made 405bhp without the charger but part throttle openings caused judder in the drive train. It was also going to be difficult to connect up to the supercharger outlet so it was eventually dropped. I still have this setup and if anyone would like to try it for a twin turbo set up or similar they are welcome to try it.
Will post up more project pictures later.
This was the supercharger bracket. I got this lazer cut and welded together by a specialist to my design. I needed to make some spacers up to get the pulleys to run true.
This was the first attempt at an inlet plenum, I ran the engine last summer with this on without the supercharger, joolz mapped this set up with the MBE and it made 405bhp without the charger but part throttle openings caused judder in the drive train. It was also going to be difficult to connect up to the supercharger outlet so it was eventually dropped. I still have this setup and if anyone would like to try it for a twin turbo set up or similar they are welcome to try it.
Will post up more project pictures later.
Well done Paul, that looks really good. Excellent news to hear its driveable and so satisfying to hear of a fellow DIY'er getting there. BUT.....
Don't think for one minute this is the last step, its just the start of phase two
Definitely think you've done the right thing keeping it simple by using largest supercharger you can fit on and not plumbing in an intercooler, would have been a headache.
Obviously the cams are far from ideal for forced induction but having the larger supercharger will hopefully keep the intake temps low enough, it'll be THE measurement to keep an eye on.
Did you manage to get any trumpets in the plenum? Won't really effect the top power much if not but may make mapping the low speed regions difficult, cylinder robbing etc.
All the best,
Rich.
Don't think for one minute this is the last step, its just the start of phase two
Definitely think you've done the right thing keeping it simple by using largest supercharger you can fit on and not plumbing in an intercooler, would have been a headache.
Obviously the cams are far from ideal for forced induction but having the larger supercharger will hopefully keep the intake temps low enough, it'll be THE measurement to keep an eye on.
Did you manage to get any trumpets in the plenum? Won't really effect the top power much if not but may make mapping the low speed regions difficult, cylinder robbing etc.
All the best,
Rich.
Boosted Cerb said:
Did you manage to get any trumpets in the plenum? Won't really effect the top power much if not but may make mapping the low speed regions difficult, cylinder robbing etc.
I dont have trumpets as room above the engine is limited and I dont want a bonnet bulge. I hope by keeping individual throttles and moving them to the correct place, ie after the injectors on each intake it should minimise robbing and possibly increase part throttle responce due to better fuel atomisation.The supercharger looks bigger than it is due to the angle of the photo. Its rated at 750bhp max so its not small but as the Vortech range of superchargers go up to 2400bhp it is one of their smaller units.
I will try and find the pictures of the Plenum with the top off as its not just an empty box, there is an inner plenum that hopefully helps distribute the air evenly over all cylinders.
Jammy Dodger said:
short induction loop and no intercooler should mean relatively low losses. My guess stands at 600bhp assuming 7+ psi. If he can achieve 9 psi then all the better 
That's only part of the story. I have the same blower on my Wedge engine and I have got well over 540 bhp out of it when fitted to a 5.2 l V8. Current incarnation is aiming for 600 ish with bigger charge cooled plenum and water injection and higher boost. However when John Eales and I were doing the work, he did a series of experiments with the same charger and found that detonation was an issue with high compression ratios and high power NA engines. Air charge temps easily got out of control. So much so that the engine had to be backed off so much that it was making less power than a NA special. We also found that standard fuel pumps were unreliable at the flow rates needed. I use two pumps in parallel with heavy duty cabling to ensure that the pumps got the current they needed. In addition the system needed a huge blow off valve to prevent the charger from destroying itself due to back pressure when the throttle is shut.
Hi steve, thanks for the info any advise, tips are very welcome,
what boost are you running on the wedge. I'm guessing that it must be quiet high as your increasing your power from 350ish to 540bhp. Also what ECU are you running?
I did increase the cumbustion chamber size to 52.5cc which was quiet a lot of metal to remove. I took a measurement and worked out the CR to be around 10.5:1 static. I know ideally around 9:1 would be better but I'm not sure what the dynamic CR would be on this engine as it has so many factors to consider and I think the only real concrete test will be to try it.
I did seek advise from Vortech and they say at low boost values of around 5 to 7 psi a charge cooler and blowoff valve are not necessary and can in some cases cause more problems than they solve.
I think its worth trying in its current state to see what happens and then I can decide from there on which way to go.
I have not built the car as a racer, Its a road car with full aircon, CD player, fluffy dice and so on.... so I'm only aiming for over 500bhp hopefully at something less than 7500rpm as I think it is rev's that destroy engines and not power.
what boost are you running on the wedge. I'm guessing that it must be quiet high as your increasing your power from 350ish to 540bhp. Also what ECU are you running?
I did increase the cumbustion chamber size to 52.5cc which was quiet a lot of metal to remove. I took a measurement and worked out the CR to be around 10.5:1 static. I know ideally around 9:1 would be better but I'm not sure what the dynamic CR would be on this engine as it has so many factors to consider and I think the only real concrete test will be to try it.
I did seek advise from Vortech and they say at low boost values of around 5 to 7 psi a charge cooler and blowoff valve are not necessary and can in some cases cause more problems than they solve.
I think its worth trying in its current state to see what happens and then I can decide from there on which way to go.
I have not built the car as a racer, Its a road car with full aircon, CD player, fluffy dice and so on.... so I'm only aiming for over 500bhp hopefully at something less than 7500rpm as I think it is rev's that destroy engines and not power.
I would think you'd need a blowoff valve of some kind. If you shut the throttle at 6krpm then either your new plenum will burst at the seams, or you'll maintain whatever pressure the SC can muster, which will give a big injection of air when you open the throttle again (drivetrain shunt on/off throttle), as well as putting strain on the SC and belt/chain
Edit: forgot to say it looks awesome
Edit: forgot to say it looks awesome
Edited by FarmyardPants on Tuesday 7th February 14:25
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