Bentley Turbo R Track Car!
Discussion
V8 FOU said:
The exhaust manifolds, turbo, and downpipes will be Zircotec coated to help reduce underbonnet temps and also the chargecooler which is water cooled, will be coated as it sits in the V of the engine. Water injection to also reduce intake temp and the bonnet will be louvered. Phantom reckoned the turbo wasn't big enough as the boost kept dropping, but I have had this problem before with elevated charge temps, so I reckon the water injection etc may exacerbate this.
More power will come from the above, also bigger injectors and a stand alone ecu - a visit to Dave Walker will be on the cards! The aim is for about 600bhp.
The critical thing with this motor is to keep exhaust back pressure as low as possible. This engine really struggles to control it's exhaust valves, and the valvetrain control is marginal at the std levels of boost. If you attempt to "wind up the boost" all you will do is PI your pistons to death or melt your turbo when the valves bounce about! So, you need a large short exhaust system post turbine, and don't fit a turbine. I think long and hard about getting the later valvetrain from the twinturbo black label engines (ideally, the 500bhp spec one). Also, it's enourmously "Knock limited" as it is such a low speed engine, so lowest charge temps, highest octaine fuel is very very important!More power will come from the above, also bigger injectors and a stand alone ecu - a visit to Dave Walker will be on the cards! The aim is for about 600bhp.
The ECU is, iirc, an old Magnetti Marelli unit, like the original sierra Cosworths, and is very easy to "chip"....
I'm all for a tidy classic, but what needs to be remembered is any car is just a bunch of metal bits stuck together, and not an infallible god. They will not last forever, so you may as well do what you want with it. I don't see people stood at goodwood revival shouting "oi! You fool! You might obtain a ding driving your Ferrari 250 like that!", they are cars, made to be driven, and owned by whoever wants to own it for their own pleasure. Don't hate on others coz they haven't done what you want them to, buy your own and polish it all day if that floats your boat. Otherwise let people like this guy build a mad bentley coz he can and wants to.
Will you be running bigger turbos? These guys...
https://www.facebook.com/pages/Wisbech-Engineering...
...have a few generations experience with Bentleys.
https://www.facebook.com/pages/Wisbech-Engineering...
...have a few generations experience with Bentleys.
habanero said:
What a great project. Ignore the haters.
I look forward to outbraking you into some hairpin at a trackday soon :-)
I didn't see any hate - just questioning why you'd start with what appeared to be a good car - which seemed a waste.I look forward to outbraking you into some hairpin at a trackday soon :-)
But, having had further detail of the issues with the car, it turns out it was a good choice to work on.
Pictures can be deceptive.
Max_Torque said:
The critical thing with this motor is to keep exhaust back pressure as low as possible. This engine really struggles to control it's exhaust valves, and the valvetrain control is marginal at the std levels of boost. If you attempt to "wind up the boost" all you will do is PI your pistons to death or melt your turbo when the valves bounce about! So, you need a large short exhaust system post turbine, and don't fit a turbine. I think long and hard about getting the later valvetrain from the twinturbo black label engines (ideally, the 500bhp spec one). Also, it's enourmously "Knock limited" as it is such a low speed engine, so lowest charge temps, highest octaine fuel is very very important!
The ECU is, iirc, an old Magnetti Marelli unit, like the original sierra Cosworths, and is very easy to "chip"....
Thank you for your input. Higher boost won't affect the valvetrain unless higher revas are used. Cosworth couldn't get any more revs/power from this unit! The knock limiting will be part of the new ecu setup, but the low charge temps and good fuel will prevent any damage. Also, bear in mind that if it does let go a good used engine costs around £2K! The exhaust has the original small cat on the engine plus the original straight through centre box, then side exits. This has made a huge difference to the power. The Phantom race car runs a reliable 650BHP.The ECU is, iirc, an old Magnetti Marelli unit, like the original sierra Cosworths, and is very easy to "chip"....
Ultimate engine power is not a priority at the moment. Weight loss and handling and brakes first! But again thanks to you and others for usefull input.
I range Quaife today as they are local about an ATB diff. Looks like £3500 for a one off. Hmmm, I may just get a viscous diff for the mo'.
V8 FOU said:
Higher boost won't affect the valvetrain unless higher revs are used.
Unfortunately it will. Higher boost = higher pre turbine pressure = slower closing exhaust valves! And as i said, you'll find the enigne is marginal in this respect as stdV8 FOU said:
Cosworth couldn't get any more revs/power from this unit!
I developed the 400/450 & 500 bhp spec twin turbo engines for Bentley whilst i worked at Cosworth! I've probably spent 3 years of my life doing performance development on the 6.75 ;-)V8 FOU said:
The knock limiting will be part of the new ecu setup,
Whilst you can quite easily prevent the engine from detonating by retarding the ignition timing, if you don't reduce boost as this occurs (which it will) you will just melt the exhaust valves / turbine insteadV8 FOU said:
The exhaust has the original small cat on the engine plus the original straight through centre box, then side exits. This has made a huge difference to the power.
You need to ditch any/all post turbine exhaust restriction you possibly can with this engine!V8 FOU said:
The Phantom race car runs a reliable 650BHP.
At what engine speed are they claiming 650bhp?With the greatest respect to you experience, my information about the whys and wheres come from a good source and the general opinion is that Blackpool engines don't make power as well as the single turbo.
Now, whilst you take this very seriously, I hate to disappoint you, I don't really!
The engine output isn't a big priority. It will, as stated, get full heat management, water injection and a stand alone ecu which will reduce boost when needed.
I'm fully appreciative of where you are coming from, but this is not a full on serious project. Just and old git of over 40 years experience of doing similar stuff having a laugh. Nothing to prove. When you have been through what I have in the last 5 years - near fatal accident, 3 months in hospital,total f
k ups by said hospitals, loss of wife of 18 months in accident and now disabled, I just want to piss about having a very different car for track use. No big agenda.
But thanks again for you input. It is appreciated at face value.
Now, whilst you take this very seriously, I hate to disappoint you, I don't really!
The engine output isn't a big priority. It will, as stated, get full heat management, water injection and a stand alone ecu which will reduce boost when needed.
I'm fully appreciative of where you are coming from, but this is not a full on serious project. Just and old git of over 40 years experience of doing similar stuff having a laugh. Nothing to prove. When you have been through what I have in the last 5 years - near fatal accident, 3 months in hospital,total f
k ups by said hospitals, loss of wife of 18 months in accident and now disabled, I just want to piss about having a very different car for track use. No big agenda.But thanks again for you input. It is appreciated at face value.
I really like what your doing with your Bentley. I bought the race car off phantom motor cars and ran it on the road for a couple of years. On the track it was set up to run at 700bhp, I had it set for 530bhp which after many discussions with the the guy that set it up he thought it best to turn down the power due to the restrictions caused by the side exhausts. To get a reliable 600 plus horsepower on pump fuel the car needed wider exhaust all the way from the turbo's. My car had been fitted with a prototype sultan of Brunei twin turbo engine that was 530bhp when it left the factory. If I can help give me a shout
Wisherm said:
I really like what your doing with your Bentley. I bought the race car off phantom motor cars and ran it on the road for a couple of years. On the track it was set up to run at 700bhp, I had it set for 530bhp which after many discussions with the the guy that set it up he thought it best to turn down the power due to the restrictions caused by the side exhausts. To get a reliable 600 plus horsepower on pump fuel the car needed wider exhaust all the way from the turbo's. My car had been fitted with a prototype sultan of Brunei twin turbo engine that was 530bhp when it left the factory. If I can help give me a shout
Unfortunately, the first thing you need to do with six3/4 power figures is knock roughly 100 off the claimed number!The MPW Brunei cars were claimed at 550bhp, but in reality made only 430, and only for about 3min until intercoolering system heat soaked, after that it stuggles to make over 400!
I've NEVER seen a six3/4 over a genuine 600bhp on ANY fuel!
Paul - just have fun!
The dreaming & scheming, planning & purchasing, trial & error, tweeking & changing - as you know that's where the fun is.
It's the climb, not the view from the top!
You've got a legion of attentive supporters here!
As a "Bentley Boy" you'll need to sport the required look:
The dreaming & scheming, planning & purchasing, trial & error, tweeking & changing - as you know that's where the fun is.
It's the climb, not the view from the top!
You've got a legion of attentive supporters here!
As a "Bentley Boy" you'll need to sport the required look:
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff