god910 Posted August 29, 2004 Report Share Posted August 29, 2004 Valvetrain is easy Mechanical Roller. And I don't know if it's the same "Potter" or not, but there is a Potter, John I believe, that is pretty big in the Cadillac performance arena. (500" BB) Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted August 30, 2004 Report Share Posted August 30, 2004 one thing i should add is that it doesnt matter when the power comes on off the line for traction its how it hits that affects traction... Quote Link to comment Share on other sites More sharing options...
phantomshado Posted August 30, 2004 Report Share Posted August 30, 2004 I'm pretty new to this engine design thing, going to be getting really in depth really quickly here, and I'd like to get some ideas/info. Wouldn't you want a super long stroke to generate torque? The greater length of travel would seem to lend itself to leveraging the crank and therefore the movement of the car. Upper HP may be taken out, but the low end torque would be there in spades. Quote Link to comment Share on other sites More sharing options...
gp90se Posted August 30, 2004 Author Report Share Posted August 30, 2004 I'm pretty new to this engine design thing, going to be getting really in depth really quickly here, and I'd like to get some ideas/info. Wouldn't you want a super long stroke to generate torque? The greater length of travel would seem to lend itself to leveraging the crank and therefore the movement of the car. Upper HP may be taken out, but the low end torque would be there in spades. yup, basis on a stroker motor (383 for example) is ALL low end torque, but the reason a lot of people seem 2 want a shorter throw is to turn higer RPMs, which under boost, will make a good amount of torque and a lot of hosepower, which translates to higher trap speeds. Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted August 31, 2004 Report Share Posted August 31, 2004 the other thing, is if you go with a long rod, and a long stroke, you end up losing some of your torque because your piston G loads (going from upward motion, to downard motion) is increased. This increases by one of two things, either A - decreasing rod length, or B - Increasing Crank throw (or stroke length) - if you use a shorter throwing crank, and a longer rod, you will get rid of your high rod angles which will increase the dwell angle, and decrease the G load on the pistons - in turn freeing up more torque and horsepower, both low end and some on the top. Someone said "it doesn't matter when the power comes on off the line for traction its how it hits that affects traction..." I think I almost understand this statement - not to be mean, but I don't think I fully understand it. I'm seeing it, and getting: It doesn't matter how much torque you have off the line when it comes to traction it's how fast the torque is applied to the tires. meaning the higher the torque is in the low rpm's the less traction you will have.: This is VERY correct, but you still want all the torque you can get off the line, because the turbo engines won't start to produce any real power untill they start to spool up. these engines (the 3.1's) have a crank throw of 3.31" and a rod length of 5.7" - if you used the 3" throwing crank (2.8's) and a longer rod, you'd be able to run extremely high in the rpm's as long as the valve train could keep up because the piston velocity will still be lower - I can get you the exact calculations if you want - but for a reliable, fast, powerful engine, I'd use the 3.1L crank with a 6" rod and turbocharge it. You'll have great low end torque, and the turbocharger will give you the power up top, if you wanted to just swap the crank, go for it, but remember, it will be a smaller engine, and your turbocharger probably won't be as efficent, so you won't make the power you once had. --DaveFromColorado Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted September 5, 2004 Report Share Posted September 5, 2004 Also, it will still have a good amount of torque. I'm thinking around 7-800 whp, and 650-780kb/ft of torque. It will lag a bit of the line, but what better way to catch tracion? what i meant by sayin its how it hits for traction is someone said that if you had turbo lag or less lowend you would be able to hook up better...yes off the line you will hook up right away but once that power hits your gonna break loose...just because you have traction right away doesnt mean your gonna keep it...ive seen this demonstrated to me many times by friends with 450-500whp hondas...one example is a friend of mine that has an integra gsr that puts down 462whp off the bottle and can break em loose in all 5gears--its really insane...and yes the more torque you have off the line the better Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 5, 2004 Report Share Posted September 5, 2004 Ahh, okay, I understand now. Basically what you'd need for that type of a situation is a better suspension. you're hinting at "you'll need traction at all speeds for all ammounts of torque/horsepower" I've seen TONS of turbocharged cars (including my mustang) that it will do just fine, but as soon as the turbo spools up, ya gotta back outta the gas to keep the tires on the ground. altho it can be fun when tryin' to screw with the ricer kids. --DaveFromColorado. Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted September 8, 2004 Report Share Posted September 8, 2004 I've seen TONS of turbocharged cars (including my mustang) that it will do just fine, but as soon as the turbo spools up, ya gotta back outta the gas to keep the tires on the ground. altho it can be fun when tryin' to screw with the ricer kids. Ha...I know. My bros 88TC does the same. especially after the SPEC ceramic clutch upgrade. But Electronic boost controller will keep you grounded. 8) Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 8, 2004 Report Share Posted September 8, 2004 Boost controler? why would I want one of those? I don't even have a wastegate! seriously, I don't run the wastegate on my 'stang when I've got 110 leaded in there and the timing **way** back. because the motor can handle all the extra boost in the bottom end - the only thing that really sucked about my old setup, is my oil return line was SHIT and rotted out right away and dumped all my oil on the highway. Hey, is your Bro a member on http://www.turboford.org - may be somethin' he'll want to check out if he's not. --Dave. Quote Link to comment Share on other sites More sharing options...
Guest TurboSedan Posted September 8, 2004 Report Share Posted September 8, 2004 whoa....how much boost are you running doing that? :shock: i run a simple $25 grainger valve on my GTS, and WILL be doing the same on my TGP engine....i am pretty much against any form of ECM controlled wastegates i'm considering using 2 grainger valves (2 stage boost control) once i go 3-bar cal (not on the TGP engine of course). Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 8, 2004 Report Share Posted September 8, 2004 I had seen as high as 26lbs on the street and it was DAMN fast ... the engine kept running very well for a while, till I lost that damn return line. --Dave. Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted September 8, 2004 Report Share Posted September 8, 2004 were you running 110 with that 26lbs on the street? how much did you run at the track? i will be running 20 on street with pump gas and 25-30 at the track depends how fast 25lbs gets me...all on stock longblock from my talon ive never ran an EBC before but from what i hear they are overrated and overpriced... Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 8, 2004 Report Share Posted September 8, 2004 yeah, it was just 26lbs on the street, I was takin' every mustang 5.slow that I went after. most of 'em were modified. I have the whole thing run with solid lines (brake lines) and I keep the boost controler valve in the car, and when I'm driving on the street I have it adjusted all the way down to 6lbs just to keep the stress off the engine (because I often like to step on it) but when I start goin' against people, I start raising the boost till it hits the 26lb mark (fully unregulated) The talon's are good, but the stock rods are pretty weak, just be careful of that. --Dave. Quote Link to comment Share on other sites More sharing options...
FastSE2DR Posted September 9, 2004 Report Share Posted September 9, 2004 the stock 2g rods are weak...the 1g rods will take 400+whp before you think about changing them...a lot of people run 1g rods and 2g pistons and call it a built motor and run really fast...the stock 1g motor has 7.8:1 compression and the 2g motor has 8.5:1 so with the 2g pistons you get the compression of the 2g with the strength of the 1g... Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted September 9, 2004 Report Share Posted September 9, 2004 So if the stock trans are too unstable at high rpm..6500+..the engine is going to have to be overbored...3.4L block and a 2.8 or destroked 2.8 crank...right? The larger piston should get enough air in there...am I right?. This should also unshroud the valves a tad and creat a better swirl or pour in the incoming air to the cylinder. :!: Electronic boost controlers help alot getting out of the hole (on quick boost building turbos)and when the power pours on first (big turbos spooling after the hole)...after that...scruew it..full booost. I don't like the idea of taking timming off out of the hole or down the track. Thats me. Yea...my brothers been trying to get on the turboford site for a while..but his password never worked..and when he tried again...they never got back to him. Heres something I wrote on the beretta forums..I think it holds true to BOOST. Max or high Boost is used to compensate for poor flowing pipes or heads. A engine will not produce the power or inhale the airflow the turbo is pumping due to low stock VE and/or restricions on the pipes. Your turbo can be producing a 2.2 density ratio before the IC pipes/IC and be pumping 35lbs min of air ...but the intake manafold will only see about 1.6 to 1.9 ...at best 2 in density ratio after all the pipe bends, ristrictions, IC. And about 250lbs min of air or so. Rasing the boost to squize the air in can cause the air flow to imporve inside the engine...but the total power or airflow of the turbo demenishes. You can see the boost difference when you put a guage on the turbo oulet and one behind the TB...or even close to the intake port of the head. Quote Link to comment Share on other sites More sharing options...
DaveFromColorado Posted September 9, 2004 Report Share Posted September 9, 2004 this is true, Boost is a relative term. it all depends on how much air (in CFM) your car is able to consume. --Dave. Quote Link to comment Share on other sites More sharing options...
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