Discussion
corvettedave said:
I was also thinking LS7 tuned up, until i found out that a few have been having problems, the ls7 is a bored out ls3 block, so therefore its been made weaker slightly, i think the best value for money is a LSA, ie ls3 block, not bored out, comes with supercharger, standard bhp 550, new map and smaller supercharger pulley gives you 650 bhp and still modern day reliability etc.
LSA may sound like good value but its a twin screw S/C torque monster Circa 750Nm under 4000 rpm Std.If you increase the boost this will rise significantly, if the Ultima was a 2 ton pussy wagon maybe I could see the attraction but in a 1 tonne sports car IMO the drive would be ruined.
Best chop out the twin screw for a centrifugal, that should shift the numbers higher up the rev range.
the LS7 has sleeved bores and slightly longer stroke, but it is a hand built motor with forged internals, whereas the LSA is standard fare and (I can't quite believe) has cast pistons!
If I were going to use a "boosted" LSA in anything I'd have to junk the cast pistons in favour of forged for peace of mind.
F.C. said:
LSA may sound like good value but its a twin screw S/C torque monster Circa 750Nm under 4000 rpm Std.
If you increase the boost this will rise significantly, if the Ultima was a 2 ton pussy wagon maybe I could see the attraction but in a 1 tonne sports car IMO the drive would be ruined.
Best chop out the twin screw for a centrifugal, that should shift the numbers higher up the rev range.
the LS7 has sleeved bores and slightly longer stroke, but it is a hand built motor with forged internals, whereas the LSA is standard fare and (I can't quite believe) has cast pistons!
If I were going to use a "boosted" LSA in anything I'd have to junk the cast pistons in favour of forged for peace of mind.
if the LS7 has sleeved bores, then that's even worse, more meat taken away from block to get the sleeves in there, and we all know what happens with sleeves over time!If you increase the boost this will rise significantly, if the Ultima was a 2 ton pussy wagon maybe I could see the attraction but in a 1 tonne sports car IMO the drive would be ruined.
Best chop out the twin screw for a centrifugal, that should shift the numbers higher up the rev range.
the LS7 has sleeved bores and slightly longer stroke, but it is a hand built motor with forged internals, whereas the LSA is standard fare and (I can't quite believe) has cast pistons!
If I were going to use a "boosted" LSA in anything I'd have to junk the cast pistons in favour of forged for peace of mind.
its well known the standard "fare" LS3 block can handle alot power, the standard crankshaft can handle 1000bhp, the ls3 can handle upto 700 bhp, before anything needs to be changed, above that better con rods are needed and maybe start thinking about better pistons etc
listen the cost difference between the 2 engines is huge, so i will happy take the risk that the LSA has too much torque, other sources have lead me believe there isnt a problem with that
saying the Ultima GTR chassis cant handle that much torque/power seems a little lacking in some faith in a great piece of auto engineering the guys at Ultima came up with
dave
I've just finished an ls3 engined, carrera 2 gearbox, gtr, I wanted old school sbc characteristics so stuck the " biggest" cam I could in it, dynoed at 535 Hp ( flywheel ), it has a lumpy idle, and pops and bangs on the overrun, 1st gear is useless, and I'm always going for a non existent 7th. But, you can have fun with the other ratios because the engine is a bit more peaky, the first time I went out in it i aborted the run, I thought the clutch was slipping, it wasn't , the wheels were spinning!!
corvettedave said:
saying the Ultima GTR chassis cant handle that much torque/power seems a little lacking in some faith in a great piece of auto engineering the guys at Ultima came up with
dave
Where did I say that?dave
I said IMO it would ruin the drive, that much torque can spoil traction and if not, ruin a gearbox.
confusionhunter said:
well...I think that prooves the ls3 as the best bang for buck. Its significantly more expensive for lsa/ ls7 for only 15% more power without yet more investment.....
Screengrab of American Speed engine pricesEdited by confusionhunter on Monday 20th October 18:18
Can someone tell me what AS do to an LS7 that makes it cost £7000($11200) more than a crate engine?
My standard crate LS7 produces 577hp (English Hp!) with a matched length header and 98db exhaust.
As for the "how much horsepower is enough" argument. I had an LS2 of about 440hp in my car when I purchased it second hand. It was quick but I felt it/I needed more. The cost of tuning an LS2 or LS3 (with a dry sump for track use) was as much as a standard LS7 so that was the route I took. It gives me more potential in the future if I want it, but I have to say that as it stands the car is just right for road use.
Lots of torque for low rev acceleration and warp speed if you hang on in the gears. If you are daft enough to floor it with cold tyres/damp roads then yes it will bite but the throttle pedal goes both ways....
Paul
PS. I am at the gearbox rebuild stage though!!!!
My standard crate LS7 produces 577hp (English Hp!) with a matched length header and 98db exhaust.
As for the "how much horsepower is enough" argument. I had an LS2 of about 440hp in my car when I purchased it second hand. It was quick but I felt it/I needed more. The cost of tuning an LS2 or LS3 (with a dry sump for track use) was as much as a standard LS7 so that was the route I took. It gives me more potential in the future if I want it, but I have to say that as it stands the car is just right for road use.
Lots of torque for low rev acceleration and warp speed if you hang on in the gears. If you are daft enough to floor it with cold tyres/damp roads then yes it will bite but the throttle pedal goes both ways....
Paul
PS. I am at the gearbox rebuild stage though!!!!
Storer said:
Can someone tell me what AS do to an LS7 that makes it cost £7000($11200) more than a crate engine?
My standard crate LS7 produces 577hp (English Hp!) with a matched length header and 98db exhaust.
As for the "how much horsepower is enough" argument. I had an LS2 of about 440hp in my car when I purchased it second hand. It was quick but I felt it/I needed more. The cost of tuning an LS2 or LS3 (with a dry sump for track use) was as much as a standard LS7 so that was the route I took. It gives me more potential in the future if I want it, but I have to say that as it stands the car is just right for road use.
Lots of torque for low rev acceleration and warp speed if you hang on in the gears. If you are daft enough to floor it with cold tyres/damp roads then yes it will bite but the throttle pedal goes both ways....
Paul
PS. I am at the gearbox rebuild stage though!!!!
They supply the ancillaries at a whopping premium! My standard crate LS7 produces 577hp (English Hp!) with a matched length header and 98db exhaust.
As for the "how much horsepower is enough" argument. I had an LS2 of about 440hp in my car when I purchased it second hand. It was quick but I felt it/I needed more. The cost of tuning an LS2 or LS3 (with a dry sump for track use) was as much as a standard LS7 so that was the route I took. It gives me more potential in the future if I want it, but I have to say that as it stands the car is just right for road use.
Lots of torque for low rev acceleration and warp speed if you hang on in the gears. If you are daft enough to floor it with cold tyres/damp roads then yes it will bite but the throttle pedal goes both ways....
Paul
PS. I am at the gearbox rebuild stage though!!!!
ETS what gearbox do you/did you have fitted?
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