Were did I go wrong with my engine combo
06-03-2019, 01:00 AM
#41
When we talk durations we are also talking about valve events. A 240+ cam is way too big for a street driven 383 efi with hyd roller if you want it to drive nice and make lots of low end torque. This isn't a tuner problem it's a combo problem. Cam is too big for this application and the TB is known to have idle issues.
It will help people understand it better.
06-03-2019, 05:12 AM
#42
To me it sounds like the tuning sucks if it won't idle and feels gutless at wot. Also your cam is a bit too big, especially for that low-ish 3600 stall. You could take your current cam specs and subtract 10 degrees from the intake and exhaust duration and it would be great with your setup (232/240 113lsa 109icl). Or leave the cam you have, put in a 4400 stall, and rev the **** out of it.
06-03-2019, 05:52 AM
#43
The heads are trickflow 220 as cast. I bought em bare installed 2.055 / 1.57 Manley valves , Texas speed speced the cam , I did tell them it was a street car when I ordered my cam intake and roller rockers from them , as for the throttle body the car will idle all day long it’s just comeing a stop it’s an nightmare have to step on the brake and gas to keep it running, the compression ratio is 11:4 , I have no problem buying a new cam for the car , but what cam should I go with that will work the best with my engine/ heads combo
Btw still think a cam like Darth and I mentioned will overall be a better match for what you've described wanting ~ 238/242 ish or 237/245 (thats whats in my 416)
06-03-2019, 07:03 AM
#44
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Originally Posted by SuperSport01
To me it sounds like the tuning sucks if it won't idle and feels gutless at wot. Also your cam is a bit too big, especially for that low-ish 3600 stall. You could take your current cam specs and subtract 10 degrees from the intake and exhaust duration and it would be great with your setup (232/240 113lsa 109icl). Or leave the cam you have, put in a 4400 stall, and rev the **** out of it.
06-03-2019, 07:14 AM
#45
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Originally Posted by Lsbmer
Surprised no one has mentioned intake valve closing degrees.
Assuming a 4-degree advance on the OP current cam, IVC is still 50 degrees. That is why it is gutless. Low dynamic compression.
To truly take advantage of this cam it needs rpm and compression. If the OP plans to rev this thing, then mill the heads for some compression. Would be a lot of milling. If not, then swap the cam.
If you want to test the theory, out in a keyed timing set much cheaper and advance the cam 3-4 degrees. See how much better it runs.
06-03-2019, 08:53 AM
#46
Wrong cam for the compression ratio and not enough stall(4k bare minimum) combined with not enough rpm. That throttle body can also be a pain. Darth summed it up. You need about 12.1 static to get the dynamic compression where it needs to be with that cam. Big cams need compression and RPM. 6500rpm isn't anywhere near enough...7k is a start.
06-03-2019, 10:41 AM
#47
As much as this cam theory banter is fun and all, it still fails to address the fact that OP is nowhere near his goal(s) of a streetable N/A 500whp combination, nor will a new cam provide that solution. To be fair, the goal wasn't realistic to begin with which is why we are all headed down the valve events rabbit-hole. It should have been supercharged from the outset, and OP needs to let the shop and vendors that steered him wrong know this - and he needs to take a strong look in the mirror for a healthy dose of accountability too.
06-03-2019, 11:06 AM
#48
Cam motion torquey stroker or similar (maybe even a tad smaller) will work perfect for his gear, stall head and compression. Will run 91 pump without issue and will make tons of power. Should have DCR of about 8.4 and should peak around 6300. Which is perfect for the fast. 500 wheel isn't realistic from a daily driveable street car (meaning no surging or hunting for idle) especially with a long runner fast. You will need RPM and $$$$ spent on valvetrain.
06-03-2019, 11:12 AM
#50
I built an 383 ls1 trickflow 220s Fast 102 intake /tb tsp custom grind cam speced for my engine, 242/250 duration / .365/.353 -.620/.600 @ 113 lobe separation 1&17/8 long tubes and full tsp duel exhaust , yank 3600 stall. 9in with 3:89 gears , my t/a made 448/430 to the ground on a dyno jet , they tuned it speed density , the car feels real gutless driving around, won’t idle, even @ wot car feel like a dog , could it be the tune or is it over cammed? I called BTR the other day and they recommend there stage 4 cam .
06-03-2019, 06:03 PM
#51
Well yes, I figured a 232/240 113/109 would be a bit small -ish. But he wants driveability, doesn't have much compression, and has a mediocre stall speed. I was looking at it in the sense of what would fix most of his issues without the need to change anything else.
06-03-2019, 08:44 PM
#52
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I called Texas speed today and told them what’s going on and they said that my 242/250 cam is right for my combo , and it’s all in the tune, After I hung up the phone I called cam Motion and they said that they think the 242/250 is a tad too big and Recommend there Torquey stroker cam 235/242 , Before I ordered this cam tomorrow, does anyone have this cam in an similar engine combo, hows it feel down low , they said it makes power from 2800-6800 I would really hate to go threw all this again ,
Last edited by Rickys2003svt.cobra; 06-03-2019 at 08:54 PM.
06-03-2019, 08:53 PM
#54
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Wish you could put a copy of the tune up.
06-03-2019, 09:17 PM
#55
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06-03-2019, 09:20 PM
#56
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I am positive I could fix the drivability stuff. Not perfectly stock but at least get it to do what it should.
Oh whale.
Oh whale.
06-03-2019, 11:07 PM
#58
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06-03-2019, 11:08 PM
#59
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06-03-2019, 11:49 PM
#60