9.0 ltr quad cam twin turbo V8 in an Ultima!
Discussion
Yes as the titles says, please see the below link for a Mercury Marine racing 9.0 ltr quad cam twin turbo V8 (about 1600bhp normal fuel) in an Ultima GTR! Bonkers!
http://forums.corvetteforum.com/c6-forced-inductio...
(towards the bottom of the page)
Chris.
http://forums.corvetteforum.com/c6-forced-inductio...
(towards the bottom of the page)
Chris.
F.C. said:
Well that is a corker!
No mention of transmission type but this engine IS available and intended for automobile use, 1300 odd BHP on pump gas.
20-30% fuel efficiency saving over similarly rated engines....
enough gas in our tanks to go to the shops and back I'd imagine 
The car has a Ricardo transaxle. It appears to have been built without regard to cost, and not driven, as far as I could tell.No mention of transmission type but this engine IS available and intended for automobile use, 1300 odd BHP on pump gas.
20-30% fuel efficiency saving over similarly rated engines....
enough gas in our tanks to go to the shops and back I'd imagine MattYorke said:
On mercuary's site. I was looking at their TT racing boat engines and the 1350s have a flat torque curve and there is a q&a somewhere that says the boost is varied throughout the rpm range so sounds like torque management to me. Could be spouting BS though. LolI think the turbos they use are VNT / VGT units. Be intresting to see how fast they spooled on a car. Also intresting to see if they can cope with the heat as the boat engines run water cooled exhaust manifolds.
The challenge of marine engines to is quite different to that of road engines - basically a marine engine is all about torque. They want a nice broad, flat, torque curve, which is why diesels suit so well. The challenge with a turbo motor is usually getting it on boost at all - ideally you want an unwastegated turbo (since they tend to burn the wastegates out), but then getting the turbo on boost enough to get the boat up and running enough for the motor to make boost is a challenge in itself - it's chicken and egg, hence why superchargers are common (iirc some of the volvo marine engines have both a supercharger and a turbo). This merc motor is lovely though and looks like a strong competitor to the turbine crowd.
There are drives that will take more or less any torque number you can throw at them - have a look for arneson.
There are drives that will take more or less any torque number you can throw at them - have a look for arneson.
chuntington101 said:
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MattYorke said:
The challenge of marine engines to is quite different to that of road engines - basically a marine engine is all about torque. They want a nice broad, flat, torque curve, which is why diesels suit so well. The challenge with a turbo motor is usually getting it on boost at all - ideally you want an unwastegated turbo (since they tend to burn the wastegates out), but then getting the turbo on boost enough to get the boat up and running enough for the motor to make boost is a challenge in itself - it's chicken and egg, hence why superchargers are common (iirc some of the volvo marine engines have both a supercharger and a turbo). This merc motor is lovely though and looks like a strong competitor to the turbine crowd.
There are drives that will take more or less any torque number you can throw at them - have a look for arneson.
Hmm... but that's no Diesel though.There are drives that will take more or less any torque number you can throw at them - have a look for arneson.
chuntington101 said:
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MattYorke said:
The challenge of marine engines to is quite different to that of road engines - basically a marine engine is all about torque. They want a nice broad, flat, torque curve, which is why diesels suit so well. The challenge with a turbo motor is usually getting it on boost at all - ideally you want an unwastegated turbo (since they tend to burn the wastegates out), but then getting the turbo on boost enough to get the boat up and running enough for the motor to make boost is a challenge in itself - it's chicken and egg, hence why superchargers are common (iirc some of the volvo marine engines have both a supercharger and a turbo). This merc motor is lovely though and looks like a strong competitor to the turbine crowd.
There are drives that will take more or less any torque number you can throw at them - have a look for arneson.
Matt, why would no wastegates help the turbos spool faster? Wastegates are there only to reduce drive presure and thus limit boost presure. The wastegates have nothing to do with spooling the turbo(s) and they will be shut at low rpm and boost presures anyway.There are drives that will take more or less any torque number you can throw at them - have a look for arneson.
chuntington101 said:
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The turbos pictured don't have wastegates because they are VNT / VGT turbos (can't remember which they use). These turbos constantly alter the AR on the turbine side to control boost and reduce spool.
They don't. The issue with marine (especially race) engines is the high duty cycle tends to burn wastegates out pretty quickly and you then can't get on boost at all - it's just a case that you don't want to design a weak spot in - which has obviously been considered in the design of these.
MattYorke said:
They don't. The issue with marine (especially race) engines is the high duty cycle tends to burn wastegates out pretty quickly and you then can't get on boost at all - it's just a case that you don't want to design a weak spot in - which has obviously been considered in the design of these.
But on a marine application the EGTs are lower anyway thanks to the water cooled manifolds. You can even get water cooled wastegates these days. Why would the wastegates get 'burnt'? I can see why the waste gates get high duty as the engines will be at max power for long periods of time (gates open).
I think part 2 of your reply answers part 1.
Max throttle, Max EGT, open wastegate in one of the hotter parts of the exhaust means no cooling to the valve (even if the body is cooled)
I can only speak based on my observations and conversations with people who have built way more engines than me - but SwipeWipes burnt a wastegate in the CTC race one year and have now switched to wastegateless turbos (and correspondingly long spool up time to get on the plane and on boost).
Max throttle, Max EGT, open wastegate in one of the hotter parts of the exhaust means no cooling to the valve (even if the body is cooled)
I can only speak based on my observations and conversations with people who have built way more engines than me - but SwipeWipes burnt a wastegate in the CTC race one year and have now switched to wastegateless turbos (and correspondingly long spool up time to get on the plane and on boost).
I understand the whole idea is to get a good boost at lower rpms which means the wastegate will open early to limit overall boost (not an expert but I assume the amount of boost is somehow linear related to the amount of exhaust gases going throuth the turbine). In diesel engines they use variable turbine geometry so I assume they are using those in the diesel PENTA engines, why not in the turbo charged V8 world ?
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