does anyone upgrade their valves when doing a motor build ?
i would assume valves would help with increasing the redline ?
my car is going in this tuesday for the motor build and i was just curious if i should change the valves


ive kind of decided to change my route, and not go for a crazy hp build


if theres any way to get 700-750 with an 8500 redline, that would be better for me vs a 1000hp build with a 7k redline

 

Hmmm. Your "redline" or maximum usable RPM has no real bearing on your HP output. MOST cars (not all) are long past their usable HP and TQ by redline. Your valve size also will have no bearing on your redline. They WILL however, give you more HP and TQ as an engine is just an air pump and "more air in, more air out" = usually more power. Maybe some engine builders can add some insight, (which I realize is what you want, just thought I would chime in as I am bored at work.)

 

to be honest, im not so concerned with the amount of power i would make or not make in this case, its more for increasing my speed per gear
especially in 6th

ive hit 202 before , and i always wanted to hit 220
with a 315 30 tire and an 8500 redline, this should be doable

 

Yes, more RPM and bigger tires will get you more MPH. But you DO also need the power to pull that kinda speed. Remember, you need exponentially more power to push the air at that speed, depending on how long a distance you are using to try to achieve that speed. Maybe the guys that have been over 220 can tell us what their redline is and what size tire they ran...?

 

i heard (i think it was from a member here) that the 996tt only needs 300rwhp to hit 200

 

??? in what distance? With 300rwhp, it seems it would take miles to get to that speed. What 996tt only has 300 rwhp?

 

Steve , there is NO WAY you will hit 220 mph with out extensive power mods !!!!! you need big power for that look at arts car, Joes , bellos , etc ,

and i dont know who told you , that you only need 300 whp to hit 200mph, even it was so , you would need miles and miles , of mexican realestate for that . look at the texas mile, you can kinda get a feel of how much power those cars have and what mph they did.

 

ive taken my car to 202mph (indicated on digital speedometer, so i'm sure it was off) and to to be honest it wasnt THAT hard to get there...
im at 500rwhp, and my car is slammed


you guys dont think that another 200+rwhp wouldnt get me another solid 20 miles per hour?

the only thing that i could see would hurt me would be the obnoxious rear wing that i'm putting on the car

 

At the mile, it takes an additional 100whp to gain 5mph. and the wing will hurt.

 

I don't think he is talking about the standing mile though. I don't think 500rwhp would get him to 220 either, regardless of distance.

While it may not take "that" long to get up to 200, just remember how much ground you are covering going 200mph (about 100 yards per sec), so trying to accelerate 5mph in a fized distance obviously takes a good bit more power. At 220, you could be covering an extra ~30' every second.

 

I realize he didn't specify a mile. I was just trying to explain what kind of power it takes to run a certain MPH in a mile and how much More it takes to go that much faster. In reality, it likely would take 750-800 rwhp to go 220 on an empty highway and you would probably need 1-1/2 miles or so to do it, maybe more. As an example, my bike ran 190 mph in Texas (1 mile), it ran 205 in Maine (1-1/2 miles) all with the same gearing. I might have gone a little faster in Texas if I changed my gearing, but not that much...

 

gotta agree with TT , also keep in mind the faster your going, the more the resistance you will have .

And i hope your not trying to do 220 on a public highway...

 

larger valves coincide with porting and cams,
porting cams and new valve spring quickly hits 8k extra(no valves), the valve springs and valvetrain at this point will withstand 10krpms as ive been told. but you need the rest to also hold up.

so if you dont have a built bottom end 3.8litre perfectly balanced engine and all the supporting goodies i dont see how larger valves are gonna help that much.

with a solid stock bottom end and supporting bolt ons you can hit 800whp with jsut turning the boost up jsut depends on how much coin your ready to shell out.



these cars do 190mphish stock at 415 crank horsepower so 500whp hitting 200mph isnt that out of this world, hes talking about on the open road not in the standing mile. and 200who more into the 700whp range should net you close to 220mph but thats hard to say as most dont go that fast =)

 

July 30th, 31st and Aug 1st. Loring, Maine. 1-1/2 mile land speed event. Long, straight, and smooth as glass. They do use ECTA rules, so full cages are necessary. Good place to find out how fast your car is.

 

The biggest limiter on the 996 valvtrain in regards to rpm is the dual stage lifters.After that the springs would be a close second and then comes time to think about the crank.My advice is stay under 7500 rpms with a stock like setup.