DD cam
#22
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For NA operation with excellent heads and cam durations in the 220's-230's range and lift in the high .5xx's or more, you get to a point of diminishing returns with increased exhaust lift and duration, maybe gaining a few ponies up top but usually at the expense of overall powerband.
My cam lobes have equal I and E lift, but I'm running 1.6 I and 1.5 E rockers, so I have LESS exhaust valve lift. I drop to 5400 on the shifts, so I can't afford to give up midrange torque.
My cam lobes have equal I and E lift, but I'm running 1.6 I and 1.5 E rockers, so I have LESS exhaust valve lift. I drop to 5400 on the shifts, so I can't afford to give up midrange torque.
#23
9 Second Club
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For NA operation with excellent heads and cam durations in the 220's-230's range and lift in the high .5xx's or more, you get to a point of diminishing returns with increased exhaust lift and duration, maybe gaining a few ponies up top but usually at the expense of overall powerband.
My cam lobes have equal I and E lift, but I'm running 1.6 I and 1.5 E rockers, so I have LESS exhaust valve lift. I drop to 5400 on the shifts, so I can't afford to give up midrange torque.
My cam lobes have equal I and E lift, but I'm running 1.6 I and 1.5 E rockers, so I have LESS exhaust valve lift. I drop to 5400 on the shifts, so I can't afford to give up midrange torque.
OP like pat said and i did earlier.....the converter and gear depends ALOT on the ability of the car to accelerate to its potential.......
#24
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Mike, that shift extension dilemma is killing me. I tried a different converter (9.5" custom) that flashed to 4800 on the launch and kept the rpm at 6000 after the shifts, but I gained nothing compared to this super-efficient little 8" ATI that only flashes to 4400. The 9.5 just didn't keep the power hooked up in the upper revs like this one does. I even spoke at length to Charlie at ATI about it, and he's convinced if he loosens this one it will behave like the 9.5 I tried. If I had your rpm potential, I'd be running a lot looser than I am!
#25
11 Second Club
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Hitman is right on the money.
A dyno tune doesn't mean squat for driveability. Part throttle/low rpm tuning is what you need, and that takes some finess/experience, not just tweaking WOT timing and mixture on the dyno.
Even with your gears, a competent tuner can make that 228 cam very driveable. I have a 228 in mine, PCMforLess mail order tune handles all the driveability aspects just fine, we just tweaked the WOT mixture and timing on the dyno.
A dyno tune doesn't mean squat for driveability. Part throttle/low rpm tuning is what you need, and that takes some finess/experience, not just tweaking WOT timing and mixture on the dyno.
Even with your gears, a competent tuner can make that 228 cam very driveable. I have a 228 in mine, PCMforLess mail order tune handles all the driveability aspects just fine, we just tweaked the WOT mixture and timing on the dyno.
#26
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Your converter soaks up all the cam surge. Bucking/surging gets old around town as well as not being able to just lug around at 1500 rpm's. My dad's ls1 ws6 with a 212/218 is 10x more fun to drive around town. It drives just like stock and has off-idle torque which I miss. Even though it's probably down 30-40rwhp it feels just as fast as mine too.
"And BTW, my cam is a 108 LSA.
I can manually lock the converter and lug it; no surging or bucking."
#27
9 Second Club
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Mike, that shift extension dilemma is killing me. I tried a different converter (9.5" custom) that flashed to 4800 on the launch and kept the rpm at 6000 after the shifts, but I gained nothing compared to this super-efficient little 8" ATI that only flashes to 4400. The 9.5 just didn't keep the power hooked up in the upper revs like this one does. I even spoke at length to Charlie at ATI about it, and he's convinced if he loosens this one it will behave like the 9.5 I tried. If I had your rpm potential, I'd be running a lot looser than I am!
Your converter soaks up all the cam surge. Bucking/surging gets old around town as well as not being able to just lug around at 1500 rpm's. My dad's ls1 ws6 with a 212/218 is 10x more fun to drive around town. It drives just like stock and has off-idle torque which I miss. Even though it's probably down 30-40rwhp it feels just as fast as mine too.
#28
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yea i know id pick up huggeee with the ATI converter but then i'll never drive my car again......i take pride in running 10.2 then driving 50 miles to a car show with it lol.......and mudering the occasional LS1 on the highway lol......but yea we are loosening my 9.5" Vigilante up to a 5300 and I'll still have my lockup so i can cruse at 75mph nice nice.......if i ever switch im going th350 with a serious converter......like a 5800 or so lol
#29
10 Second Club
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Yup, I'm convinced an 8" converter is the only way to go unless you're making more than 800 hp. The weight, efficiency, flash rpm, etc are great for 95% of cars. Mine is loose, I'm throwing some hy-gard in it to tighten it up hopefully to the 5300-5400 range, then in goes a 15 degree bigger cam later that will let me use all that converter. If I was building a h/c or cam only car I'd be tempted to use a 7". I'll bet mike would go 9.90s with a th350 and converter change
#31
9 Second Club
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Yup, I'm convinced an 8" converter is the only way to go unless you're making more than 800 hp. The weight, efficiency, flash rpm, etc are great for 95% of cars. Mine is loose, I'm throwing some hy-gard in it to tighten it up hopefully to the 5300-5400 range, then in goes a 15 degree bigger cam later that will let me use all that converter. If I was building a h/c or cam only car I'd be tempted to use a 7". I'll bet mike would go 9.90s with a th350 and converter change
then maybe in goes the right trans/converter
but yea what pat says how does that work???
PM us if u want so we dont hijack this dudes thread
#34
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My specs, wanting something more than the 503 in my A4 car, with less lift than the XFI280 (467). I thought shortening the exhaust duration would help prevent over-scavenging with a free flowing exhaust and efficient exhaust ports on the AI 190cc heads. Aiming to cross the traps near the top of 3rd at about 6300. I'll keep in mind adding 2 more degrees exhaust duration and see what AI has to say about the duration spread as well. Thanks for the opinion.
#35
11 Second Club
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Your converter soaks up all the cam surge. Bucking/surging gets old around town as well as not being able to just lug around at 1500 rpm's. My dad's ls1 ws6 with a 212/218 is 10x more fun to drive around town. It drives just like stock and has off-idle torque which I miss. Even though it's probably down 30-40rwhp it feels just as fast as mine too.
Wasn't lack of lowend one of your complaints with your old setup? Wasn't that much improved by replacing popular parts with good ones?
#36
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I have BOTH of those sitting on the shelf awaiting my builds. One for my 97 SS M6 & one for my gf's 95 Z28 M6. I can't make my mind up which one is going in my car. When I say both, I mean down to the 1.6 with the 466 & 1.7's with the 503.
#38
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OP you need some 4.10's to resolve most of these issues. I am running a LE 224/230 on a 107LSA and and there is only a hint of surge under 1.8K RPM but it does not bother me and yes it has a good tune. The tires bust loose at 2.5K RPM and peak power holds on till 6.4K RPM too.
If you are determined to not change the gears, you will simply need a tamer cam like the 503 or maybe even a little less. And as already stated, you might run into the intake runners on the heads being too big for the cam.
You should call Lloyd and talk cams.
If you are determined to not change the gears, you will simply need a tamer cam like the 503 or maybe even a little less. And as already stated, you might run into the intake runners on the heads being too big for the cam.
You should call Lloyd and talk cams.
#40
10 Second Club
iTrader: (26)
hy-gard... it's a thick hydraulic fluid from john deere. I'll be running it straight with some red dye added (it's colorless). It's been proven to reduce wear, drop trans temps 10% and tighten the converter 5-10%. It's cheap too, runs about 13 bucks a gallon. If you're looking to loosen up the converter a little with the same fluid temp and wear advantages they make a low-viscosity version