norotor7

iTrader: (2)

I have read plenty of turbo cam threads, and know that a cam with a lot of over lap bleeds boost, but how much? And how does it effect spool up and the over all power curve?

My build is a forged 347, zo6 intake, 317 heads, 9.2scr, tc76. I have a stock 00 cam and a 224/224 112+4 sitting in my garage. Lets compare these 2 cams.

I know that the 112lsa will bleed some boost but I am not looking for making the biggest numbers possible. I am more intreasted in a smooth and broad power band.

Will the stock cam start building boost at a lower rpm? What effect does the +4 advance have on a turbo?

Between these 2 cams, wich one would you use, and why?

Photochop

iTrader: (74)

Sell both cams and buy a custom grind for your setup, neither you have listed is optimal.

I have a very similar setup as yours, only difference being a 76gts turbo and my cam is a 227/223 .585/.575 115 LSA

No numbers for my car yet - just got it going a couple weekends ago and still awaiting full tune and some miles on the fresh motor. The kit came off of TURBO LS1 SS's car (from this site) and he had great luck with the cam in his 6L motor.

Schantin

iTrader: (6)

Usually the +4 will not help you. The advance ground into the cam means that 112LSA is acting like a 108LSA in the car. Good for pushing the torque curve into the lower RPM range, but generally bad for overlap and top-end power production.

You want to run a cam that ends out with near zero or even a negative overlap. Most cams for FI are running a 115LSA or so for this reason. Don't want the intake charge going out the exhaust due to overlap.

Now, by default you have picked a low LSA cam that WILL work. I had a TR224 cam on my STS car. That profile (112+4) actually gives 0 degrees overlap when plugged into a Ve calculator. It did well for the low/mid-range on my car till the boost kicked in. I swapped to a CC228 on a 115LSA. That + 317 heads gave me 453RWHP/432RWTQ at only 5PSI. On 8-9PSI it would have been in the 500's easy. Honestly think both cams were about equal on the power production.......till about 5KRPM where the added lift/duration of the 228 helped out.

There's a ton of info in the sticky's in the Internal Engine section. Enough reading to make your head hurt

Good luck

ArklaTexan

iTrader: (24)

Virginia Speed speced one for my GenTTr twin Setup and I love it so far. It is 220-224 .581/.581 114+4 It idles perfectly no surging at any speed and sounds like stock. It is a great FI cam. Much easier to drive then my old Mega Death LOL

norotor7

iTrader: (2)

I know the 224 cam will bleed a little boost, but is the extra lift and duration enough to make up for it on the top end? Will one cam start spooling the turbo at a lower rpm?

ArklaTexan

iTrader: (24)

Mine was custom designed to get the turbos to spool a little quicker, I can find the pm and I will add it to this post in a bit.

Re: Cam

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Originally Posted by ArklaTexan
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Originally Posted by Shawn @ VA Speed
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Originally Posted by ArklaTexan
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Originally Posted by Shawn @ VA Speed
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Originally Posted by ArklaTexan
Shawn,

Thanks for the help in advance. My wife despised my Mega Death Cam and Long Tubes. She didn't like the loudness, the surging , or the chopy idle. (I LOVE it) To make her happy and still maintain if not increase my power level I am going with the Gen TTr turbos. They use the stock manifolds so that will quiet it alot. So what I need is a cam that will take advantage of what the turbos do best. I will be using 317 worked heads with upgraded springs valves retainers etc. I am looking for a stock like idle with little to no surging. This will go on my LS1 for the time being until I save for the built 402. If you recommend I pick a cam for the ls1 with the turbo that is fine, I can sell it when the 402 comes it. I am open to all suggestions and advice!

Thanks,
Daniel


i would def reccomend a different cam for the ls1 than the 402,totally different requirements.

for the ls1 a 220-224 .581-.581 on a 115+4 lsa,i know its might sound kinda small but i made 750rwhp in an ls1 with twin 61's on it and it idles nice.

let me know

Thanks,

Shawn

What is the +4 on the LSA? Those are about the lift I was expecting and I was thinking in your ballpark of 220-224. Any particular separation I was thinking 224/228.

.581 lift on both? and what combo of 220-224 or are you refering to intake-exhasut.


the =4 means there is 4degress of advance ground into the cam,helps idle a little better and really helps spool up.the 220 is intake and 224 exhaust

Thanks for the help I think I will take your advise, is this a custom grind or does comp have this on the shelf.


its a custom grind

norotor7

iTrader: (2)

Thanks, thats some good info. I'm so use to dealing with na cams, just trying to get educated on turbo cams.

I know I am going to make more than enough peak numbers with what ever cam I chose. This is in a 2800lb rx7. Trying to figure out how different cams effect the torque curve and initial turbo response.

I now have an 03 ls6 cam too. I'll probably use that. I would like the lope of the 224, but it sounds like it might bleed to much boost