NineExcellence
Albert Park
- Joined
- 21 Sep 2009
- Messages
- 1,588
Hi,
We took over a 964 supercharger project early last year that had been done by someone in Europe. Despite our best efforts at making it reliable, it really needed to be reworked completely. The main issues were getting the car boost leak free and keeping intake temps down sufficiently that the engine would not pull back on the power.
The car was quick (in manual form) but it never really felt spot on - the point of a supercharger is ideally to bring in lots of torque throughout the rev range and it always felt far too linear - you really had to rev the nuts off it to get it to go. When we received the car, the peak boost was around 0.42 bar. We did manage to get it up to 0.6 bar briefly at the top of the rpm range, but as soon as you fixed one boost leak, another one started. Remember na 964 is not designed to have boost put through it.
In the end I think the concept was good, but the delivery was poor. So the customer put the car to bed with our agreement, and we said that we would like to prove the concept on one of our own cars first, taking into account some of the issues we had found with him.
So we purchased a 964 (actually in tiptronic form) from Japan as a donor car. And so the project started. The project has taken about 5 months in total, working in between normal business of course.
We decided to take the engine out, do the upgrades and try and get it boost leak free if possible. The design of the customer project was actually quite poor - the concept of just bolting on a supercharger seems easy, but there was a lot that wasn't thought through. He had had a aquamist water/methanol injection system fitted to lower intake temp rather than intercooler but it was never reliable - we have a lot of successful experience with these system on our other 9e cars, so the concept of using water injection instead of an intercooler (space issues) was something we wanted to continue with.
In terms of the supercharger, the customer car had rotrex supercharger on. Again this was something that we were happy with - it has a separate oil cooler unlike some superchargers, so using this would be fine.
So we decided to replicate what was on the original customer car, but see if we could get it working properly. Same supercharger, same aquamist system and so on.
We designed a boost leak testing system (using pressure not smoke) as we have for 996/997 turbos. It was quite shocking on a standard NA car the amount of places it would leak from. We gradually worked solutions for each, creating custom pipe work to replace plastic/rubber connections etc. A lot of CNC parts, but you get to the point of trying to seal up one component that has multiple outlets and you just say screw this, lets remake the part in alu so it will never leak.
Eventually, with the engine on the floor, we managed to get through 1.5 bar. Now this might not seem like a lot of boost, but a stock set up wouldn't even hold 0.3 bar :grin:
We had to remove the a/c unit, to locate the supercharger. And then we created custom hardpiping (using a similar concept to maximum airflow to the supercharger like we do on turbos).
Now, the tiptronic box - it will have its lovers and haters and in a 964 it is quite basic but in manual mode it works pretty well. But we knew the limit of the torque would be too low. We managed to upgrade the box to hold 500nm tq with the help of a company in the UK who specialised in these boxes (the boxes are used in landrovers etc).
Bolt the car all back together, do the tuning and car was ready earlier this week.
Now with a NA car with compression ratio of 11:3, strictly speaking the concept of running anything more than 0.35-0.4 bar is dangerous. You need a much lower compression engine (9:0 or less) to start running over this. But, we took the decision that the engine could be resolved (e.g. build a lower compression engine at a later date) as the most important thing was whether the car could be boost leak free, with lower intake temps etc.
Now, remember the customer car I mentioned. We only saw regularly 0.45 bar or so, and when we had tried to fix some leaks in situ, we had seen 0.6 bar at one brief moment before it leaked again. Want to guess what boost we saw on ours with the same supercharger etc?
0.85-0.9 bar
And never mind the boost, my god what power. It actually felt far too quick :grin: The torque fill is amazing - completely different to the customer car - actually feels like a turbo.
We brought the car back in after its first road test. Now we faced an issue - too much boost for the compression, so we did a little modification to the tune to help as much as possible. Alternatively we could, if we wanted, put on a larger pulley wheel in the supercharger to reduce boost.
Since it is our shop car, the leave the boost where she is won the day. :grin: - we know we need to build the engine at some point, and frankly running the car at a higher boost level will be a stiffer test of the whole supercharger set up.
So performance :grin:
Prior to the upgrade we did a run and recorded 0-60 in 6.1 seconds, 0-100 in 11.6, 0-110 in 17.8 seconds. Yes yes very slow I know.
Now, 0-60 4.38 seconds, 0-100 in 9.55 and 0-110 in 11.5 seconds.
and top speed is just a few miles an hour short of 180mph.
To give some idea, the 60-100mph is as quick as a stock 996 Turbo.
996GT3 is also 9.5 seconds to 100mph.
I would say she has around 400hp, certainly at this boost level.
We plan to run her for two days at Spa in early April. Of course she has lots of other things, like full suspension, runs 3.25 d camber all round, pss10s, solid this, solid that.
Anyway, I have been driving her everyday for the last week. It is the most fun car I have driven in a long time, stupid fast in any gear. Hopefully the engine will hold up and we can prove the concept works, in which case, we can either lower boost to run on a stock engine, or up the boost on a lower compression engine.
Keep you updated how she runs.
Ken
We took over a 964 supercharger project early last year that had been done by someone in Europe. Despite our best efforts at making it reliable, it really needed to be reworked completely. The main issues were getting the car boost leak free and keeping intake temps down sufficiently that the engine would not pull back on the power.
The car was quick (in manual form) but it never really felt spot on - the point of a supercharger is ideally to bring in lots of torque throughout the rev range and it always felt far too linear - you really had to rev the nuts off it to get it to go. When we received the car, the peak boost was around 0.42 bar. We did manage to get it up to 0.6 bar briefly at the top of the rpm range, but as soon as you fixed one boost leak, another one started. Remember na 964 is not designed to have boost put through it.
In the end I think the concept was good, but the delivery was poor. So the customer put the car to bed with our agreement, and we said that we would like to prove the concept on one of our own cars first, taking into account some of the issues we had found with him.
So we purchased a 964 (actually in tiptronic form) from Japan as a donor car. And so the project started. The project has taken about 5 months in total, working in between normal business of course.
We decided to take the engine out, do the upgrades and try and get it boost leak free if possible. The design of the customer project was actually quite poor - the concept of just bolting on a supercharger seems easy, but there was a lot that wasn't thought through. He had had a aquamist water/methanol injection system fitted to lower intake temp rather than intercooler but it was never reliable - we have a lot of successful experience with these system on our other 9e cars, so the concept of using water injection instead of an intercooler (space issues) was something we wanted to continue with.
In terms of the supercharger, the customer car had rotrex supercharger on. Again this was something that we were happy with - it has a separate oil cooler unlike some superchargers, so using this would be fine.
So we decided to replicate what was on the original customer car, but see if we could get it working properly. Same supercharger, same aquamist system and so on.
We designed a boost leak testing system (using pressure not smoke) as we have for 996/997 turbos. It was quite shocking on a standard NA car the amount of places it would leak from. We gradually worked solutions for each, creating custom pipe work to replace plastic/rubber connections etc. A lot of CNC parts, but you get to the point of trying to seal up one component that has multiple outlets and you just say screw this, lets remake the part in alu so it will never leak.
Eventually, with the engine on the floor, we managed to get through 1.5 bar. Now this might not seem like a lot of boost, but a stock set up wouldn't even hold 0.3 bar :grin:
We had to remove the a/c unit, to locate the supercharger. And then we created custom hardpiping (using a similar concept to maximum airflow to the supercharger like we do on turbos).
Now, the tiptronic box - it will have its lovers and haters and in a 964 it is quite basic but in manual mode it works pretty well. But we knew the limit of the torque would be too low. We managed to upgrade the box to hold 500nm tq with the help of a company in the UK who specialised in these boxes (the boxes are used in landrovers etc).
Bolt the car all back together, do the tuning and car was ready earlier this week.
Now with a NA car with compression ratio of 11:3, strictly speaking the concept of running anything more than 0.35-0.4 bar is dangerous. You need a much lower compression engine (9:0 or less) to start running over this. But, we took the decision that the engine could be resolved (e.g. build a lower compression engine at a later date) as the most important thing was whether the car could be boost leak free, with lower intake temps etc.
Now, remember the customer car I mentioned. We only saw regularly 0.45 bar or so, and when we had tried to fix some leaks in situ, we had seen 0.6 bar at one brief moment before it leaked again. Want to guess what boost we saw on ours with the same supercharger etc?
0.85-0.9 bar
And never mind the boost, my god what power. It actually felt far too quick :grin: The torque fill is amazing - completely different to the customer car - actually feels like a turbo.
We brought the car back in after its first road test. Now we faced an issue - too much boost for the compression, so we did a little modification to the tune to help as much as possible. Alternatively we could, if we wanted, put on a larger pulley wheel in the supercharger to reduce boost.
Since it is our shop car, the leave the boost where she is won the day. :grin: - we know we need to build the engine at some point, and frankly running the car at a higher boost level will be a stiffer test of the whole supercharger set up.
So performance :grin:
Prior to the upgrade we did a run and recorded 0-60 in 6.1 seconds, 0-100 in 11.6, 0-110 in 17.8 seconds. Yes yes very slow I know.
Now, 0-60 4.38 seconds, 0-100 in 9.55 and 0-110 in 11.5 seconds.
To give some idea, the 60-100mph is as quick as a stock 996 Turbo.
996GT3 is also 9.5 seconds to 100mph.
I would say she has around 400hp, certainly at this boost level.
We plan to run her for two days at Spa in early April. Of course she has lots of other things, like full suspension, runs 3.25 d camber all round, pss10s, solid this, solid that.
Anyway, I have been driving her everyday for the last week. It is the most fun car I have driven in a long time, stupid fast in any gear. Hopefully the engine will hold up and we can prove the concept works, in which case, we can either lower boost to run on a stock engine, or up the boost on a lower compression engine.
Keep you updated how she runs.
Ken