longer exhaust duration?
#62
TECH Senior Member
No, the thread is still bookmarked.
It is one thing to purchase an item, and a totally different thing to know how to use it!
You threw a challenge, now back it up.
In October, I'll send u my track slip.
It is one thing to purchase an item, and a totally different thing to know how to use it!
You threw a challenge, now back it up.
In October, I'll send u my track slip.
#63
Originally Posted by PREDATOR-Z
The 1.8/1.85 rockers are also a stock cam band aid to get these lifts up (Or anything with .550 lift or less).
If you want higher lifts just get a cam that has them in the first place.
Also the place to look is your powerband and what are you using it for. Personally I've always been a fan of high torq/medium revving cams, just simply because I make up for the top end by spraying.
Also a lot of poeple look at high duration and stratospheric lifts, while they can achieve the same results with "smaller cams", taking into account overlap and lsa.
If you want higher lifts just get a cam that has them in the first place.
Also the place to look is your powerband and what are you using it for. Personally I've always been a fan of high torq/medium revving cams, just simply because I make up for the top end by spraying.
Also a lot of poeple look at high duration and stratospheric lifts, while they can achieve the same results with "smaller cams", taking into account overlap and lsa.
If you run 1.4'ish diameter springs then using 1.75's and ending up with .630 lift is a good thing. If youre worried about spring life, you are playing with the wrong toys. I run .612 lift and use 1.75's now.
I agree with one thing: If you are going to do it all at once and have the money, get the cam with the lift you need but be sure to factor in the valve covers if you want 1.7's or the ubiquitous yella-terra heavies if you want to stay under 7k on the revs.
Keep in mind that trap speeds are affected by limited revs if you run anything over 4.10's and 120mph traps. Revving to 7500 is one way to get more headroom. I assume a forged motor is in use as I have for this.
PredatorZ: what cam/heads do you use with the spray? Big split?....I went 6 more degrees on exhaust for duration and it is awesome.
Last edited by Spinmonster; 05-24-2004 at 12:07 AM.
#64
Yes you need one or two more degrees exhaust duration for restrictive exhaust runners and or exhaust systems. Predator z your theory is nice but I have seen more cams with straight split overpower reverse splits many times over . I am sure there are situation where a reverse split would make more power, but they are more rare situations than straight splits making more power. I agree with a bigger charge equals more pressure which equals faster exhaust exit, but this only holds true for efficient exhaust scavenging which is not what this post is about. This post is about inefficient exhaust scavenging in my case with stock heads and shorty headers. This is where I would gain rwhp with a longer exhaust duration like what we took votes on earlier in this post and you got out voted.
Last edited by 52172; 05-24-2004 at 11:00 AM.
#65
Originally Posted by 52172
Predator z your theory is nice but I have seen more cams with straight split overpower reverse splits many times over . I am sure there are situation where a reverse split would make more power, but they are more rare situations than straight splits making more power.
Some advice I offer for a more peaceful existence here is to take whatever advice you are given (say thanks for the help offer) and use it or not but without the lectures when you disagree with the advice given. I thought the reverse split was a great idea with stock heads. If you feel that you have vastly superior knowledge to all those who recomended it, spare those guys that offered to help you the bashing, thank them and just do what you are going to do. If you keep up with this type of know-it-all and argumentative posting, you will soon hear an echo when you need to get future info.
Do you recall saying this:
"Yes I am open to suggestions what cam would you recommend for me DenzSS? I want over 400 rwhp and have just enough torque to beable to drive it on the street with 3:42 and run like a raped ape when needed. Seek and destroy those fords."
I think what you meant was you are open to suggestions that are the same as what you are going to do anyway....get a conventional split, big cam. That isn't advice you want it is called confirmation or agreement fo your purchase. One of the key things you say is on the street. These big azz cams you are looking at will need gearing to get you back the low end performance you will loose on the street.
Last edited by Spinmonster; 05-24-2004 at 01:31 PM.
#66
Thanks for the advice I have one question why do you and predator z think a reverse split would have been the best for my set up with stock heads when everyone else voted for longer exhaust duration? I thought the reverse splits were like a bandaid for weak intakes? I know the stock heads intake runners do not flow much cfm, but same goes for the exhaust runners. I believe the boltons I have for the intake make my intake as best as possible with stock heads correct? I would like to know why then you still think I would need a reverse split if my intake is not being hindered? I know gears would help bring me up into the power band sooner, but the people that make my cam believe it will work fine with my 3:42's this is Jason at Texas speed. I do not want to hurt my gas mileage as I commute 80 miles a day on the interstate. Now that I have stage two GTP heads do you think the standard split will work great with my shorties? Why did you recommend a reverse split with dual ram air,lid,85mm maf, smooth bellow, ported LPE intake, ported TB, EGR mod etc?
#68
Now that I have bought stage two GTP heads do you think the 231/237 texas speed cam will make more useable power compared to stock heads? The heads were flow tested and flowed 310 cfm at only .550 of lift!! That equates to high intake velocity which means more power under the curve which is what a large cam needs. Am I right? I bought comp pushrods and patriot gold dual valve springs and titanium retainers with new valve seats also. I will be on the street 99 percent of the time, but when I run into my brother and his mustang or any other mustang for that matter my engine is never below 3000 rpms for that matter. I went from a roll the other day and we started out at 4000 rpms and that is where I would like my car to pull like a mo fo. I will set my rev limiter at about 6600 and shift just before that.
Last edited by 52172; 05-24-2004 at 07:45 PM.
#69
Originally Posted by 52172
Thanks for the advice I have one question why do you and predator z think a reverse split would have been the best for my set up with stock heads when everyone else voted for longer exhaust duration? I thought the reverse splits were like a bandaid for weak intakes? I know the stock heads intake runners do not flow much cfm, but same goes for the exhaust runners. I believe the boltons I have for the intake make my intake as best as possible with stock heads correct? I would like to know why then you still think I would need a reverse split if my intake is not being hindered? I know gears would help bring me up into the power band sooner, but the people that make my cam believe it will work fine with my 3:42's this is Jason at Texas speed. I do not want to hurt my gas mileage as I commute 80 miles a day on the interstate. Now that I have stage two GTP heads do you think the standard split will work great with my shorties? Why did you recommend a reverse split with dual ram air,lid,85mm maf, smooth bellow, ported LPE intake, ported TB, EGR mod etc?
I think you should do the following:
Do a search on the forum for the threads called CAM DISCUSSION parts 1&2. You will find more tech on why these things work. Having a vote/poll doesnt change the laws of physics.
As far as gears go, once you get up there in duration, you will see just how crappy a car runs under 2000-2500 rpm. ENDING GEAR myths 101:
4.10's:
1-you will pull 2200 rpm at 80 mph
2-you will get 26 mpg with 4.10's
3-4.10's HELP TRACTION by slowing down the SPEED of rotation of the tires. Just as 2nd gear is a higher speed for tire rotation; a gear UNDER 1st which is exactly what 1st will be like, will spin slower allowing the car to catch up to the rate of spin.
4-top speed is lower----not. I did 180 in 6th gear since the 4.10's made the top gear usable to those with 450-500rwhp nearing you to 200mph. (I have a C5 vette) and that was definitely NOT topped out.
Use the search deature for a lot of these topics. They are definitely old hat and always have the same wrong info from time to time.
In your case, anything you do would be better. Any cam will work. I would get one that you can grow into.
Until recently I had:
348 LS6 heads ported big time
224/230 114 cam 581/592 lift
alum flywheel
every bolt-on headers, UD pulley.....ls1 edit tuning and put down 441 rwhp......overcamming is not the only way. My car ran like stock as far as manners but pulled all the way to 7k and had no idle issues. great low-end rpm performance and I wasn't in a rush to get 15 more HP at the expense of the way it ran. These cars you read about with monster cams and no exhaust systems are great for the track but I wouldnt ever want to be in traffic with it. They get 470 or so rwhp and maybe more now with these new intake/TB combos.
#70
I would like to run 4:10's , but I think the gears on the pinion gear get smaller or less in number so it would weaken my already weak 10 bolt. I don't have money for a 12 bolt or 8.8 or 9 inch. Once I blow my 10 bolt I will get a 12 bolt and my new gear ratio will definetly be 4:10. Thanks for the advice.
#71
8 Second Club
iTrader: (13)
Wow, so much reading.
Anyway, with a mild cam (224/230 581/592 on a 114) I picked up 15hp on the top by just changing from my Edelbrock Shorties to Macs. (Neither set ups had cats)
I went to a bigger cam (232 236 572 578) and swapped headers. (Kooks)
I picked up 7 peak more HP from my Macs to my Kooks.
a 231 237 may work great, but you will leave a lot of power on the table.
Anyway, with a mild cam (224/230 581/592 on a 114) I picked up 15hp on the top by just changing from my Edelbrock Shorties to Macs. (Neither set ups had cats)
I went to a bigger cam (232 236 572 578) and swapped headers. (Kooks)
I picked up 7 peak more HP from my Macs to my Kooks.
a 231 237 may work great, but you will leave a lot of power on the table.
#72
Originally Posted by AgFormula02
Wow, so much reading.
Anyway, with a mild cam (224/230 581/592 on a 114) I picked up 15hp on the top by just changing from my Edelbrock Shorties to Macs. (Neither set ups had cats)
I went to a bigger cam (232 236 572 578) and swapped headers. (Kooks)
I picked up 7 peak more HP from my Macs to my Kooks.
a 231 237 may work great, but you will leave a lot of power on the table.
Anyway, with a mild cam (224/230 581/592 on a 114) I picked up 15hp on the top by just changing from my Edelbrock Shorties to Macs. (Neither set ups had cats)
I went to a bigger cam (232 236 572 578) and swapped headers. (Kooks)
I picked up 7 peak more HP from my Macs to my Kooks.
a 231 237 may work great, but you will leave a lot of power on the table.
Did you use the XER 232/236?
#73
Originally Posted by 52172
I would like to run 4:10's , but I think the gears on the pinion gear get smaller or less in number so it would weaken my already weak 10 bolt. I don't have money for a 12 bolt or 8.8 or 9 inch. Once I blow my 10 bolt I will get a 12 bolt and my new gear ratio will definetly be 4:10. Thanks for the advice.
I don't know from experience since I have a corvette and know nothing of the inherent weaknesses in the f-body's rear end design limitations. Perhaps someone with that info would like to chime in........but in the case of my rear end: mid 400rwhp + a 150 shot on 26" et streets does nothing to my rear gears which are 4.10's.
If you're worried about things breaking, once again you are playing with the wrong toys. Big cams like biiger rear ratios so save up fast.
#74
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4.10s will last for a while if you're careful. If you never do clutch dumps and only run the car on the street, they will be fine...and IMO are necessary...even for a stock car. I did break one set, but it was from racing at the track...no biggie, $150 for new gears isnt bad.