Increasing Displacement
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Joined: Nov 2003
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From: Rancho Palos Verdes, CA
as to why the shorter stroke.... Read this
http://www.hyundaiaftermarket.com/noncgi/u...t=004106#000000
Yes, you'll loose displacement by going with the shorter stoke crank, but I will tell you this.
DO NOT INCREASE DISPLACEMENT FOR HP/TORQUE.
That Simple. Don't do it. It's not worth it.
On a stock motor, you'd be lucky to see 3-4 WHP. On a boosted motor, it's a double edge sword. That same extra volume coming out the exhaust ports to spool the turbo faster...is also eating more air..so boost doesn't build as fast. Now, don't get me wrong, a 2.5L motor will spool a turbo faster than a 2.0L, but if you do the math.. it won't spool it 25% faster. Even though it's 25% bigger.
If you're talking about significant displacement increases, then it can be worth it (500cc or more), but it's not worth it to go from 1997 cc to 2049cc.
Just my Humble Opine.
Regarding the 1.8L vs 2.0L.... Read the link above. RPMs can be more valueable than Cubic Centimeters.
http://www.hyundaiaftermarket.com/noncgi/u...t=004106#000000
Yes, you'll loose displacement by going with the shorter stoke crank, but I will tell you this.
DO NOT INCREASE DISPLACEMENT FOR HP/TORQUE.
That Simple. Don't do it. It's not worth it.
On a stock motor, you'd be lucky to see 3-4 WHP. On a boosted motor, it's a double edge sword. That same extra volume coming out the exhaust ports to spool the turbo faster...is also eating more air..so boost doesn't build as fast. Now, don't get me wrong, a 2.5L motor will spool a turbo faster than a 2.0L, but if you do the math.. it won't spool it 25% faster. Even though it's 25% bigger.
If you're talking about significant displacement increases, then it can be worth it (500cc or more), but it's not worth it to go from 1997 cc to 2049cc.
Just my Humble Opine.
Regarding the 1.8L vs 2.0L.... Read the link above. RPMs can be more valueable than Cubic Centimeters.
Thread Starter
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ok so according to the thread, i should just keep the bore/stroke the same and just get the assembly balanced and blueprinted to set the redline to 8000?...keep in mind i am getting all forged internals including a new crank, the stock crank is good for 300-350 whp?.
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Vehicle: 2001 Hyundai Tiburon
I was thinking about doing the 1.8 crank mod for a while for a higher redline... my only question is, without a haltech, how is it possible to raise the redline?
My plan is to boost with a second set of 4 injectors. Is it possible to have a significant jump in fuel with the secondary injectors when the stock cut out? Or is there an easy way to remove the fuel cutoff?
My plan is to boost with a second set of 4 injectors. Is it possible to have a significant jump in fuel with the secondary injectors when the stock cut out? Or is there an easy way to remove the fuel cutoff?
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Joined: Nov 2003
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From: Rancho Palos Verdes, CA
Casper and Mad Machine-
Let's leave the fueling discussions for another thread.
Assuming you use forged internals, and totally re-balance the assembly for the new lighter pistons but heavier rods (forged rods are heavier than stock rods, but forged pistions are lighter than stock pistons) and then blueprint the motor clearances yeah, you can run a 2.0L as high as 8100 rpm. You'll need some kind of full ECU replacement to gain the control over fueling and ignition to rev to 8100, but it's 100% do-able. You could even keep the redline at say 7000 for cruising to your destination, then raise it for racing. Increased RPM's means increased wear. The less RPM you run, the longer the motor will last.
The advantage of the increase in RPM is threefold.
You'll move more air spinning the motor at 8000 RPM...allowing you to utilize a bigger turbo, or at least get the most out of the turbo size you choose. Just make sure you do the air/volume calculations right. You'll be able to run a bigger turbo spinning a 2.0L motor to 8000 RPM than you could running a 2.1L to 6750 RPM.
Because you've got more "elbow room" in the gearing you can dial in the power delivery to be softer to keep the car right on the edge of the traction limit. A ECU controled wastegate can do wonders here to keep you from building boost too fast in the lower gears.
The big pay off is in gearing. The longer you can make the lower gears last, the more power you're putting down to the ground via gear multiplication. In first gear, the gear multplication turns your stock 130 Ft/lbs into over 1000 Ft lbs at the wheels. Now imagine you've got 400 Ft Lbs @ the engine.... While that's bad right off the start at the drag strip, by the time you're topping out 2nd gear (@8000 RPM), you'll be doing about 80mph, and that extra RPM of high gear multplication really pays off for the top end of 2nd and all of 3rd gear.
Depending on how much power you've got and how fast you're going, you may even be able to save the shift from 3rd to 4th... that's .2 to .4 tenths right there.
Let's leave the fueling discussions for another thread.
Assuming you use forged internals, and totally re-balance the assembly for the new lighter pistons but heavier rods (forged rods are heavier than stock rods, but forged pistions are lighter than stock pistons) and then blueprint the motor clearances yeah, you can run a 2.0L as high as 8100 rpm. You'll need some kind of full ECU replacement to gain the control over fueling and ignition to rev to 8100, but it's 100% do-able. You could even keep the redline at say 7000 for cruising to your destination, then raise it for racing. Increased RPM's means increased wear. The less RPM you run, the longer the motor will last.
The advantage of the increase in RPM is threefold.
You'll move more air spinning the motor at 8000 RPM...allowing you to utilize a bigger turbo, or at least get the most out of the turbo size you choose. Just make sure you do the air/volume calculations right. You'll be able to run a bigger turbo spinning a 2.0L motor to 8000 RPM than you could running a 2.1L to 6750 RPM.
Because you've got more "elbow room" in the gearing you can dial in the power delivery to be softer to keep the car right on the edge of the traction limit. A ECU controled wastegate can do wonders here to keep you from building boost too fast in the lower gears.
The big pay off is in gearing. The longer you can make the lower gears last, the more power you're putting down to the ground via gear multiplication. In first gear, the gear multplication turns your stock 130 Ft/lbs into over 1000 Ft lbs at the wheels. Now imagine you've got 400 Ft Lbs @ the engine.... While that's bad right off the start at the drag strip, by the time you're topping out 2nd gear (@8000 RPM), you'll be doing about 80mph, and that extra RPM of high gear multplication really pays off for the top end of 2nd and all of 3rd gear.
Depending on how much power you've got and how fast you're going, you may even be able to save the shift from 3rd to 4th... that's .2 to .4 tenths right there.
Thread Starter
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ok i know what route i am going to take now..thank you everyone for your help!!!...oh one last thing...doesn anyone have recommendations on where to get a lightened/strengthened crankshaft? As for the pistons and rods i know to go with pauter and wiseco...its a given..once again thank you! laugh.gif
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From: Adelaide, OZ
Vehicle: Hyosung GT650
QUOTE (Random @ Apr 27 2005, 01:40 AM)
do the math. There's 8mm between the cylinders. with a 1mm water gap below the deck. That means each cylinder liner is 3.5mm thick.
Overboring them 1mm (0.040 ) drops the liners down to 2.5mm thick liners. That's getting thin. Especially for the high cylinder pressres a boosted motor will see.
Shaving them down 2mm would leave you 1.5mm of material. Barely thicker than the water jacket space...
Overboring them 1mm (0.040 ) drops the liners down to 2.5mm thick liners. That's getting thin. Especially for the high cylinder pressres a boosted motor will see.
Shaving them down 2mm would leave you 1.5mm of material. Barely thicker than the water jacket space...
Far be it for me to tell you you're wrong but, if you do the math right and consider that when you're talking of the liner thickness you are talking radius not diameter, overboring by 1mm on diameter will only decrease the wall thickness by 0.5mm and 2mm overbore will decrease by 1mm. Therefore if you go 2mm oversize you will still have 2.5mm wall thickness on the liner, which you said is safe
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From: SOUTH Jersey
QUOTE (IJSTBRNDU @ Apr 26 2005, 10:58 PM)
does anyone have recommendations on where to get a lightened/strengthened crankshaft?
You could probably have the stock one taken out and lightened and balanced. As it seems to handle boost til the 300/400 hp mark, it would probably work pretty good.
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QUOTE (Mad-Machine @ Apr 26 2005, 09:10 PM)
For an N/A application, I would spend the money on getting the crank balanced and lightened, and good light and balanced rods.. once you got those down, you can see about removing the rev limitor and spin the engine a little faster than 6500rpms for more power.
About the rev limit on a stock engine, it's nice theory but in reality, I run 7000rpm and someone I know runs 8000rpm on a beta. There is also a beta2 running 7600rpm that I know of...
The only internal mods are agressive cams, aluminum flywheel, UDP and the beta2 has a p/p head job. I did over 50 000miles like this, including a good 2000miles of trac. The othdr beta1 has lots of mileage too. NO PROBLEM.