How much Torque
Discussion
Gents,
I'm getting close to biting the bullet and ordering the engine for my car.
Original intention was to go for the AS LS7 for all the obvious reasons discussed in many threads here.
Then I located an engineering firm in Australia that has created their own version...
They have cast their own blocks that match the LS externally.
Into this they put quality components (they are very well know race engine builders)
The end result is 7.5L (454 ci) and an easy 600hp and 600 ft/lbs of Torque.
Dyno sheets etc etc can all be supplied when the engine is built.
My dilemma is the Torque...
It produces just over 500ft/lbs @ 2100 rpm !
They have suggested my factory supplied clutch would last a couple of weeks if I'm careful...
Cost wise, it is similar to the AS 700hp, 585 ft/lbs variant. That engine develops peak torque @ 5000 rpm. Has anyone installed this engine in an Ultima yet ?
Your opinions please:
Is 500 ft/lbs @ 2100 rpm useable in an Ultima ?
Does anyone have a recommendation for a clutch if I go this way ?
The gearbox is standard G50 03, suitable ?
Anything else I should consider in the equation ?
Thanks for any assistance you can provide guys.
Cheers
Adam
I'm getting close to biting the bullet and ordering the engine for my car.
Original intention was to go for the AS LS7 for all the obvious reasons discussed in many threads here.
Then I located an engineering firm in Australia that has created their own version...
They have cast their own blocks that match the LS externally.
Into this they put quality components (they are very well know race engine builders)
The end result is 7.5L (454 ci) and an easy 600hp and 600 ft/lbs of Torque.
Dyno sheets etc etc can all be supplied when the engine is built.
My dilemma is the Torque...
It produces just over 500ft/lbs @ 2100 rpm !
They have suggested my factory supplied clutch would last a couple of weeks if I'm careful...
Cost wise, it is similar to the AS 700hp, 585 ft/lbs variant. That engine develops peak torque @ 5000 rpm. Has anyone installed this engine in an Ultima yet ?
Your opinions please:
Is 500 ft/lbs @ 2100 rpm useable in an Ultima ?
Does anyone have a recommendation for a clutch if I go this way ?
The gearbox is standard G50 03, suitable ?
Anything else I should consider in the equation ?
Thanks for any assistance you can provide guys.
Cheers
Adam
Sorry Steve but I couldn't disagree more unless your building a full on race car - it's a rather familiar argument of Torque v BHP/revs.
It's torque that will get the car moving quickly unless you want to be screaming the nuts off it in every gear. In theory my engine will rev to over 7000rpm and I had it dynode up to 6000rpm which showed BHP still rising but peak torque is at 4400. I have a limiter set to 5800 in an attempt to reduce stress on the engine and increase longevity. With a long flat torque curve I found it quicker, easier to drive and far more relaxing to change gear early letting the torque of the engine do the work and that was during race conditions were higher BHP cars revving their nuts off were slower. High torque also means more flexible gears which helps reduce changes and improves corner entry, exit speeds and stability.
There is no circuit in the UK where I would hit the limiter in top gear down the straight so top end speed would only be an issue on the Autobahns or an event like ‘Fighting Torque’
I personally don’t think you can have too much power in the car as long as you have good car control and apply it correctly. In an Ultima if you have 300 or 500ft/lbs of torque at 2000rpm and you give it full throttle in low gears you will likely spin the wheels.
The biggest issue you face is finding the clutch and the gearbox that will take the high torque. Performance clutch for high power engines won’t have the feel and smoothness of a standard clutch from standstill but once moving that doesn’t matter as much.
I’d go for the high torque option every time as the appeal to me and part of the reason I love big V8’s is the torque.
It's torque that will get the car moving quickly unless you want to be screaming the nuts off it in every gear. In theory my engine will rev to over 7000rpm and I had it dynode up to 6000rpm which showed BHP still rising but peak torque is at 4400. I have a limiter set to 5800 in an attempt to reduce stress on the engine and increase longevity. With a long flat torque curve I found it quicker, easier to drive and far more relaxing to change gear early letting the torque of the engine do the work and that was during race conditions were higher BHP cars revving their nuts off were slower. High torque also means more flexible gears which helps reduce changes and improves corner entry, exit speeds and stability.
There is no circuit in the UK where I would hit the limiter in top gear down the straight so top end speed would only be an issue on the Autobahns or an event like ‘Fighting Torque’
I personally don’t think you can have too much power in the car as long as you have good car control and apply it correctly. In an Ultima if you have 300 or 500ft/lbs of torque at 2000rpm and you give it full throttle in low gears you will likely spin the wheels.
The biggest issue you face is finding the clutch and the gearbox that will take the high torque. Performance clutch for high power engines won’t have the feel and smoothness of a standard clutch from standstill but once moving that doesn’t matter as much.
I’d go for the high torque option every time as the appeal to me and part of the reason I love big V8’s is the torque.
Hi Steve,
I have always read your posts and been amazed at your font of knowledge with all things Ultima.
I haven't asked, but I'm sure they would fit a crank to shorten the stroke and probably come in at 7.0L
This would bring the Torque back and produce a free'er reving engine.
Is this really the way to go?
If I can develop close to peak torque at say 3000 rpm (a guess), wouldn't this be a more "driveable" engine and I would imagine a lot less stressful on the engine itself. Yep, being the numpty I am when it comes to track days, I would probably leave the right foot planted until I redlined, but it would be nice to know that I can change lower in the rev range when desired...
I was contemplating a multi plate organic clutch assembly, but when I emailed Richard at Ultima, he assured me the company 720 has a standard G50 and single plate clutch.... Your thoughts ?
Thanks for your input Chewy, In my very limited experience, I have always liked the feel of a high torque engine. The wheel spin is a very real concern, but as you say, it depends on how it is delivered.
Cheers
Adam
I have always read your posts and been amazed at your font of knowledge with all things Ultima.
I haven't asked, but I'm sure they would fit a crank to shorten the stroke and probably come in at 7.0L
This would bring the Torque back and produce a free'er reving engine.
Is this really the way to go?
If I can develop close to peak torque at say 3000 rpm (a guess), wouldn't this be a more "driveable" engine and I would imagine a lot less stressful on the engine itself. Yep, being the numpty I am when it comes to track days, I would probably leave the right foot planted until I redlined, but it would be nice to know that I can change lower in the rev range when desired...
I was contemplating a multi plate organic clutch assembly, but when I emailed Richard at Ultima, he assured me the company 720 has a standard G50 and single plate clutch.... Your thoughts ?
Thanks for your input Chewy, In my very limited experience, I have always liked the feel of a high torque engine. The wheel spin is a very real concern, but as you say, it depends on how it is delivered.
Cheers
Adam
Adam, if they cast their own engine block, will you also need them to supply emissions testing data?
i think you would be beter of going with a GM based engine as you can always fall back to their results for testing purpose.
I have just read that the IM240 test is not required in WA, but these things are a moving target. im still not sure what the requirements are for vic, or what they will be tommorrow.
Ryan
i think you would be beter of going with a GM based engine as you can always fall back to their results for testing purpose.
I have just read that the IM240 test is not required in WA, but these things are a moving target. im still not sure what the requirements are for vic, or what they will be tommorrow.
Ryan
Hi Chris and Ryan,
The block is manufactured by Kostecki Engineering in Perth.
I have been speaking with Andrew Kostecki
They have a web site, http://www.kec.com.au/, but it doesn't offer the LS based 454 as an engine option as yet.
I must ask why...
If you go through the news section of their site, on about page 4, you will find reference to the casting of the block.
I can confirm I have physically seen the finished product.
The casting was being done by a foundry in New Zealand, but has recently been moved back to WA
These guys seem exceptionally professional in their approach.
Apart from The Orbital Engine Company based in Perth, they are the only certified test center to conduct an IM240 test in WA.
Before they will supply the engine, they will confirm it will pass IM240
They feel there may be a problem with the length of the exhaust after the Cat... Basically, insufficient back pressure will not allow the Rodium to heat to the required temp and therefore reduce its effectiveness.
I will keep you posted.
Adam
The block is manufactured by Kostecki Engineering in Perth.
I have been speaking with Andrew Kostecki
They have a web site, http://www.kec.com.au/, but it doesn't offer the LS based 454 as an engine option as yet.
I must ask why...
If you go through the news section of their site, on about page 4, you will find reference to the casting of the block.
I can confirm I have physically seen the finished product.
The casting was being done by a foundry in New Zealand, but has recently been moved back to WA
These guys seem exceptionally professional in their approach.
Apart from The Orbital Engine Company based in Perth, they are the only certified test center to conduct an IM240 test in WA.
Before they will supply the engine, they will confirm it will pass IM240
They feel there may be a problem with the length of the exhaust after the Cat... Basically, insufficient back pressure will not allow the Rodium to heat to the required temp and therefore reduce its effectiveness.
I will keep you posted.
Adam
Steve_D said:
You don't want torque you want revs.
So what does it rev too and can they build you an engine with a shorter stroke?
Steve
I totally agree with this... So what does it rev too and can they build you an engine with a shorter stroke?
Steve
as an example i recently had my standard noble mapped to 400ftlb and it produced it low down, it was a very impressive torque curve but on the road it was very difficult to control without wheelspin, even once you found grip it would again loose grip further up the power band as the tyres were again overwhelmed.
Anyway I have just rebuilt the engine to race spec with high lift cams etc etc to make it rev more and move the power band up (redline 8000rpm now rather than 7000rpm)... its running low boost at the moment and happens to be running only slightly more torque to before (414ftlb) just higher up the rev range but its 480bhp now which is 90bhp more.. however it no longer suffers with wheelspin and just builds speed without the need to control wheelspin.
My Ultima ran a 383 with solid roller cams etc so that it would rev, once took it to 7500rpm at an acceleration event and it definatlly went like well.
With regard to your question on torque, I ran around 450ftlb in my Ultima (AS claimed 514ftlb but the ultima headers rob engines of 60ftlb) and the standard clutch handled that very well, others have ran around 500ftlb with upgraded porsche units (mine was a std porsche unit)... for my GTT which will be silly torque I have bought a 3plate clutch but i'm not sure how usable this will be as I think they die quickly if you use the car in traffic and so slip it too much.
I believe Steve_D runs a very torqey motor running in excess of 500ftlb and pretty sure his clutch has coped well?
andygtt said:
I totally agree with this...
as an example i recently had my standard noble mapped to 400ftlb and it produced it low down, it was a very impressive torque curve but on the road it was very difficult to control without wheelspin, even once you found grip it would again loose grip further up the power band as the tyres were again overwhelmed.
Anyway I have just rebuilt the engine to race spec with high lift cams etc etc to make it rev more and move the power band up (redline 8000rpm now rather than 7000rpm)... its running low boost at the moment and happens to be running only slightly more torque to before (414ftlb) just higher up the rev range but its 480bhp now which is 90bhp more.. however it no longer suffers with wheelspin and just builds speed without the need to control wheelspin.
My Ultima ran a 383 with solid roller cams etc so that it would rev, once took it to 7500rpm at an acceleration event and it definatlly went like well.
With regard to your question on torque, I ran around 450ftlb in my Ultima (AS claimed 514ftlb but the ultima headers rob engines of 60ftlb) and the standard clutch handled that very well, others have ran around 500ftlb with upgraded porsche units (mine was a std porsche unit)... for my GTT which will be silly torque I have bought a 3plate clutch but i'm not sure how usable this will be as I think they die quickly if you use the car in traffic and so slip it too much.
I believe Steve_D runs a very torqey motor running in excess of 500ftlb and pretty sure his clutch has coped well?
I ran my GTR with a 650hp/600ftlb SC engine, with an uprated KEP paddle clutch. In the dry with Kumhos on, it was difficult to spin the tyres on road or track unless in low gear, but maybe it was because I was trying to go around tracks fast rather than learn to drift. Imitating clarkson is not what I wanted to do. I believe learning speed on two wheels helped that balance, and I think that treating the car with a similar respect helps prevent disasters on the road. given my choice again, I would aim for more hp as possible rather than torque, and would try a turbo based unit rather than SC, each to their own, and hopefully we can all see the results of other people's take on Ultimadness as an example i recently had my standard noble mapped to 400ftlb and it produced it low down, it was a very impressive torque curve but on the road it was very difficult to control without wheelspin, even once you found grip it would again loose grip further up the power band as the tyres were again overwhelmed.
Anyway I have just rebuilt the engine to race spec with high lift cams etc etc to make it rev more and move the power band up (redline 8000rpm now rather than 7000rpm)... its running low boost at the moment and happens to be running only slightly more torque to before (414ftlb) just higher up the rev range but its 480bhp now which is 90bhp more.. however it no longer suffers with wheelspin and just builds speed without the need to control wheelspin.
My Ultima ran a 383 with solid roller cams etc so that it would rev, once took it to 7500rpm at an acceleration event and it definatlly went like well.
With regard to your question on torque, I ran around 450ftlb in my Ultima (AS claimed 514ftlb but the ultima headers rob engines of 60ftlb) and the standard clutch handled that very well, others have ran around 500ftlb with upgraded porsche units (mine was a std porsche unit)... for my GTT which will be silly torque I have bought a 3plate clutch but i'm not sure how usable this will be as I think they die quickly if you use the car in traffic and so slip it too much.
I believe Steve_D runs a very torqey motor running in excess of 500ftlb and pretty sure his clutch has coped well?
Adam GTR said:
Did they have anything to do with “making a transaxle” for a red GT40 that’s running around over their? Hi Adam
I have to agree with Chewy! Torque is a wonderful thing in an Ultima. My ProCharged SBC produces over 460lb/ft at 1,600rpm and rises to 695lb/ft at 4,000rpm. I run all this torque through a G96/50 with a changed 5th and a custom 6th gear. I went for gear ratios better suited to all the torque and the fact that I only rev to 6,500rpm. The clutch is from superclutch and is rated at 900lb/ft and is a triple plate organic and it modulates ok. The plates are solid with no springs! I'm more than happy with it. The figures will be a little higher than this now as I am running a bit more boost.
Kind regards
Dave
I have to agree with Chewy! Torque is a wonderful thing in an Ultima. My ProCharged SBC produces over 460lb/ft at 1,600rpm and rises to 695lb/ft at 4,000rpm. I run all this torque through a G96/50 with a changed 5th and a custom 6th gear. I went for gear ratios better suited to all the torque and the fact that I only rev to 6,500rpm. The clutch is from superclutch and is rated at 900lb/ft and is a triple plate organic and it modulates ok. The plates are solid with no springs! I'm more than happy with it. The figures will be a little higher than this now as I am running a bit more boost.
Kind regards
Dave
I see some differences of opinion here! I used to love the 521ftlbs with my stock LS7..but now I'm a believer that more power is better. Torque at the wheels can be achieved by shifting down a gear..so long as you have a high enough rev limit to give a usable range. 7200 on my LS7
Re clutch and transmission. Always been a big believer that these to a greater extent are affected by driving style. Snatched gearshifts I know are going to wreck my clutch and G50/05 but I know a smoother but positive change will do the trick just as well.
Re clutch and transmission. Always been a big believer that these to a greater extent are affected by driving style. Snatched gearshifts I know are going to wreck my clutch and G50/05 but I know a smoother but positive change will do the trick just as well.
Torque or Revs...... well one point that most guys tend to miss is that either / Both are great but which ever you choose to build the gearing of the box has to match... and Modified Porsche boxes are not cheap...
So low down torque is great but unless you have the longer gearing to match it's kind of pointless. The porker boxes where built for 8000rpm type engines so building a short stroke large bore engine is kind of what makes a better match for a Std box.
GMan found out that matching his rev happy 377ci with the right gears broke records, and all these engines with 600bhp+ seem wasted if there not backed up with the right ratios...
If the GTW ever makes it to a sprint event (come on Wayne !!) then perhaps we can test out if a 434 with over 620 Lbs and a correctly geared (But very expensive) G50 can sprint to 60 and 100 just as fast as Gman but with 1000rpm less revs....
So low down torque is great but unless you have the longer gearing to match it's kind of pointless. The porker boxes where built for 8000rpm type engines so building a short stroke large bore engine is kind of what makes a better match for a Std box.
GMan found out that matching his rev happy 377ci with the right gears broke records, and all these engines with 600bhp+ seem wasted if there not backed up with the right ratios...
If the GTW ever makes it to a sprint event (come on Wayne !!) then perhaps we can test out if a 434 with over 620 Lbs and a correctly geared (But very expensive) G50 can sprint to 60 and 100 just as fast as Gman but with 1000rpm less revs....
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