ok, i'll believe that the two front seats together weigh 60lbs, but you gotta have some kind of seat, and even lightweight seats weigh around 20lbs iirc.
i'm fully aware of power to weight ratio's and their effects. i also have road racing experience.
excuse my skepticism, but if i wasn't a skeptic, i would have bought and installed one of those "tornado" things
Originally posted by tnord ok, i'll believe that the two front seats together weigh 60lbs, but you gotta have some kind of seat, and even lightweight seats weigh around 20lbs iirc.
i'm fully aware of power to weight ratio's and their effects. i also have road racing experience.
excuse my skepticism, but if i wasn't a skeptic, i would have bought and installed one of those "tornado" things
Weight hurts braking, accelleration, cornering, tire and brake life in road racing.
Weight reduction is more important that power incresing in some classes.
I think he understands that. What he doesnt agree with is the 60lb seat and neither do I. Maybe if it was a full power seat, but i think that its more like 30 or so.
(wonderful.. new forum, and already an SR vs. KA thread. lol)
ok... KA and SR are Different breeds of engine. There are VERY few similarities. I personally feel the SR is better for road race type purposes b/c of the high redline. KA is better for straight line drag b/c of Displacement and Torque.
Think about when the engines were built and who for. The japanesse are into road racing, and drifting, etc. Applications which like High RPMS. Americans in the Early 90's where seen as Drag racers. (or at least that's how the japanese probably looked at the market.) To appeal to the V8 torque loving americans, they gave us a Big displacement 4 cyl w/ lots of torque. They were designed for DIFFERENT PURPOSES. Both have their good points, and Bad.
(edited out everything but the part about revving)
"Looking above the valves, the first thing that grabs you with the SR is that is only has 4 cam lobes per cam, not 8. Doesn’t it have 8 valves per side? Yep, and to get around that Nissan decided to use a rocker arm arrangement to actuate paired valves simultaneously from the single lobe. Not a bad way to do it actually. Certainly cheap to make, but at the cost of increased valve train losses and noise. The CA on the other hand has true 8 lobe cams which act directly on the top of the valves. Minimal components. Maximum revs, and no noise.
The SR has also gone back to the classic timing chain idea, and dropped the tooth belt. My theory here is it has something to do with reduced maintenance costs and less damage when the belts fly from lack of maintenance.
Obviously, the SR is a bigger engine in capacity, it has a relatively long stroke and is ‘over-square’ in design, meaning that the stroke is longer than the width of the bore. Fortunately the stroke to rod length ratio is at such a point that the engine can still rev, but it suffers classically from excess stroke. Sure, they rev out, but not anywhere near as willingly as the little CA with it’s square design (stroke=bore).
Many hi-po USA engines are using oversized pistons from the 300ZX, bringing the stroke/bore relationship back a bit, and providing a cheap source for forged pistons and further increased capacity.
Sure they rev out OK, but not anywhere near the same as a CA. I'm talking stock engines here too, not comparing an SR with aftermarket cams on modified lobe centres, which wouldn’t be a fair comparison now would it! "
Originally posted by Sykikchimp also for the Ca not out revving an SR.. See this:
From Glenn "Lumpy" Campbell on CA18 vs. Sr20
(edited out everything but the part about revving)
Here is my take on the SR valve train which is true. You can get more area under the lift curve with a finger follower type valvetrain due to the leverage ratio of the followers if higher order harmonics are controlled. More area= higher volumetric efficency accross the board.
This is why some F-1 engine designers are going away from direct valvetrains and switching to a finger follower design. What keeps stock SR's from revving is pump up of the hydralic lash adjusters which limits the RPM to about 8300 rpm which is plenty to make all sorts of power.
If you convert to solid lifters and use a rocker arm retainer, upwards of 9000 rpm is posible. Due to a better cylinder head, the SR will make better power than the CA up there.
None of this is nessesary though for turbo applications.
Although the KA is a good engine, it is difficult to get much more than 160 wheel hp NA with bolt ons (at least by my experiance) while the SR can get as much as 170 hp without going inside. For turbo streetable motors, the KA is limited to about 450 reliable hp while the SR can do over 500 in streetable trim, at least in my experiance. For stock bottom ends turboed, the KA is in the low 300's while the SR is in the low 400's.
The SR was designed as a sturdy turbo motor from the ground up while the KA has it's roots in the old L-Series motors.
No disrespect for Lumpy, he is one of my friends but he does not have access to the latest SR stuff like we have here. He does have far more CA experiance than I do. The CA is a popular engine down under but was only avalible in the lame old school 200SX in north america where it was a lackluster performer. My old AE86 would eat those cars.
I don't think the KA is limited to 400 streetable horsepower. I've seen several built KA's running well over 400 hp that get driven on the street all the time.. "Streetable" is really a subjective term anyways. I am no expert, and am not in a position to argue. I am simply stating that I have seen Streeted KA running well over 500hp as well. I hate to bring it up, but remember DUY's old car? Stock, head, cams, and intake manifold... run 10's (w/N2O)
and there is an N/A 240 on this board (guy named Aries...) with 205 whp N/A, no changes to the internals.
With enough time, and money theoretically Anything is possible.
Originally posted by Sykikchimp I don't think the KA is limited to 400 streetable horsepower. I've seen several built KA's running well over 400 hp that get driven on the street all the time.. "Streetable" is really a subjective term anyways. I am no expert, and am not in a position to argue. I am simply stating that I have seen Streeted KA running well over 500hp as well. I hate to bring it up, but remember DUY's old car? Stock, head, cams, and intake manifold... run 10's (w/N2O)
and there is an N/A 240 on this board (guy named Aries...) with 205 whp N/A, no changes to the internals.
With enough time, and money theoretically Anything is possible.
There is a big difference between seen or heard and done. I said 450 wheel hp, that is way more than 400 hp. I am not sure for how long either, high boosted KA's seem to have long term head gasket problems even when o-ringed. Block integrity is an issue also with lots of boost.
I find 205 wheel hp NA with no internal mods just about imposible to belive. Do you know exactly what the motor has on it? I would really like to know. Would Aries care to comment on his motor, I would like to learn some more on how he did it. I am struggling to make over 160 wheel hp with bolt ons and that is a huge disconnect between 160 and 205. Knowing the motor it does not seem posible, but hey, I am down to learn a few things, I don't know everything there is to know.
When it comes down to it, like I keep on saying, the KA is a good motor, very streetable and pleasent when turbocharged but the SR is better when building for maximum power output.
I agree, there is a big difference b/w doing it, and hearing about it.
fyi these are from another thread in this forum:
aries240sx:
"1995 240SX
14.677 @ 97.342 mph
Engine:
KA24DE
AEM Short Ram Intake
Jim Wolf Technologies ECU
Greddy 4-1 Headers
Custom 2.5" Cat-Back with Focuz Muffler
248 Degree 1996 Nissan Altima Intake Camshaft
246 Degree 1993 Nissan 240SX Exhaust Camshaft
Nissan Motorsports 370CC Fuel Injectors
300ZX TT Fuel Pump
Transmission Cooler
Nissan Motorsports 3.18 Gears
Enjuku Racing Front Tower Strut
Enjuku Racing Front Sway Bar
Enjuku Racing Rear Sway Bar "
I'm still trying to get a few details myself on his setup, but seems reasonable. I think he also has an N2O setup on it, but he wasn't squeezing when he ran that according to him
Originally posted by Sykikchimp I agree, there is a big difference b/w doing it, and hearing about it.
fyi these are from another thread in this forum:
aries240sx:
"1995 240SX
14.677 @ 97.342 mph
Engine:
KA24DE
AEM Short Ram Intake
Jim Wolf Technologies ECU
Greddy 4-1 Headers
Custom 2.5" Cat-Back with Focuz Muffler
248 Degree 1996 Nissan Altima Intake Camshaft
246 Degree 1993 Nissan 240SX Exhaust Camshaft
Nissan Motorsports 370CC Fuel Injectors
300ZX TT Fuel Pump
Transmission Cooler
Nissan Motorsports 3.18 Gears
Enjuku Racing Front Tower Strut
Enjuku Racing Front Sway Bar
Enjuku Racing Rear Sway Bar "
I'm still trying to get a few details myself on his setup, but seems reasonable. I think he also has an N2O setup on it, but he wasn't squeezing when he ran that according to him
Although that is a well built car with good componet choices, I can assure you that that combo will not make 205 to the wheels unless there is more there than we see. That combo should put out around 160 wheel hp +-5 hp or so.
I suspect he has NOS because there is no reason why he should have a Z fuel pump and 370cc injectors with the combo he has unless he is running a JWT NOS module.
Not knocking the car, just disputing the claim that it makes 205 to the wheels all motor, if that is indeed the claim.
honestly I'm not so sure I believe him either. I agree it shouldn't be more than about 160-170 max..
#1 the stock nissan exhaust cam is 248 not 246.
#2 he said the 240 came stock with a 3.23 final drive ratio, and he dropped it to a 3.18.. LOL he would be moving slow as hell with that gear, not to mention stock is a 4.08.
Originally posted by Sykikchimp honestly I'm not so sure I believe him either. I agree it shouldn't be more than about 160-170 max..
#1 the stock nissan exhaust cam is 248 not 246.
#2 he said the 240 came stock with a 3.23 final drive ratio, and he dropped it to a 3.18.. LOL he would be moving slow as hell with that gear, not to mention stock is a 4.08.
He says he gets 13's with nitrous.
Sounds like it does not add up to me either. You are right about the final drive!
Originally posted by Sykikchimp also for the Ca not out revving an SR.. See this:
From Glenn "Lumpy" Campbell on CA18 vs. Sr20
Obviously, the SR is a bigger engine in capacity, it has a relatively long stroke and is ‘over-square’ in design, meaning that the stroke is longer than the width of the bore. Fortunately the stroke to rod length ratio is at such a point that the engine can still rev, but it suffers classically from excess stroke. Sure, they rev out, but not anywhere near as willingly as the little CA with it’s square design (stroke=bore).
Hey, isn't the SR Square? I thought it was 86mm x 86mm.
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