Engine Work EStimate Please
Thread Starter
TECH Regular
Joined: Jul 2006
Posts: 427
Likes: 0
From: Western Kentucky
Originally Posted by Adnectere
The example was to prove that a high rpm low displacement motor at the same piston speed and ve equals a low rpm high displacement motor. In reality, even though peak powers are essentially the same, your day-to-day driving will be better with the bigger motor because you have more torque under the curve. Keep in mind that to get to peak power on a smaller motor you have to accelerate it and the car to get the rpms up & that means wasted time getting the motor on cam. A larger motor will have power on tap at any point and then even more once the rpms go up. Your ideal is a big motor running big rpms - that was ignored when I set piston speed because it limited the larger motor's power. A hot rodder will run your 402/427/440 up to 7k with no problems. Fun factor with revving rpms is ok with a mustang because it has short gears and the redline is not high - I'm betting yours is 5500-6k & your top speed in 1st is probably ~35-45. You can now rev out first and not have it be a big deal. But when you run a stock t56/ls1 to 7k that's 60+ in first gear and 90+ in second gear- you aren't going to redline that on the street in your local neighborhood. When you step up to the lsx world you are talking more speed so be careful with rpms.
Originally Posted by Adnectere
BTW IRocSS you have interesting 1/4 mile - you've got a stock c5 mph the time is way way faster. What's your hp/torque look like.
no idea yet. its getting a dynotune this spring finally. its a mail order 350cid tune that happened to drive perfet before the 3800 stall. now it needs a tune. some cam surging at low rpms. not bad though. its got a smallish cam for 383 cid (233/239) and the heads I ported myself. so there small runner heads too. I wasnt suprised at the ET vs MPH cause lots of stalled cars are like that. since the conv was unlocked, I was bleeding off some of the mph I should ba capable of getting, and very possibly Im not shifting at the optimum points either since it has yet to be on a dyno. and that was only the 3rd visit to the track over the last few years so it still needs to be sorted out shiftpoint wise too. it gets really good traction though most of my runs were in the 1.6 range with only one at 1.56 and one at 1.7x. out of 11 runs its really consistent at 11.8 on that evening. and, I think my car is starving for air at the top end of each gear since I have a pretty crappy home made cold air setup. Im planning on making an LS1 style intake with a supersucker type inlet. I cant wait to get some of those things done and get back to the track and get kicked out for not having a cage.
On The Tree
Joined: Aug 2005
Posts: 133
Likes: 0
From: TX
IROCSS - sounds like you've got your hands full on one fun project. Keep me posted on PM - I like your ride.
JBsZ06- a 414? Run that one by me, I don't think I've seen it before.
casey- Trust me when I tell you that a stock ls1 is pretty much too much power for the street. There aren't situations where you are going to floor it and not be at double the speed limit in a handful of seconds. With a 402+ you would easily make 500 hp and with the components to build it, you will be capable of spraying or blowing later on. Don't discount those - you are looking at the lsx for more power now and you will get used to it like you are used to your stang now. There is nothing wrong with those options - only your tire bill will be higher!
JBsZ06- a 414? Run that one by me, I don't think I've seen it before.
casey- Trust me when I tell you that a stock ls1 is pretty much too much power for the street. There aren't situations where you are going to floor it and not be at double the speed limit in a handful of seconds. With a 402+ you would easily make 500 hp and with the components to build it, you will be capable of spraying or blowing later on. Don't discount those - you are looking at the lsx for more power now and you will get used to it like you are used to your stang now. There is nothing wrong with those options - only your tire bill will be higher!
