TransAm396 12-17-2006, 08:21 PM 221/221 duration, .542"/.542", 114lsa
Im looking for a cam thats going to peak out around 6,000rpms to run 10psi from eithe a GT42 or a t76..does this sound like a good cam?
engineermike 12-17-2006, 11:07 PM It depends somewhat on cubic inches versus turbo size, then camshaft. For starters, that cam will probably peak well before 6000 rpm regardless of cid. My guess is that it will peak around 5600 - 5700 rpm.
The data that I've gathered on the T76GTS is as follows:
363 cid, 224/236-114, +0 adv, 5900 rpm
383 cid, 224/236-114, +0 adv, 5750 rpm
388 cid, 224/236-114, +4 adv, 5700 rpm
377 cid, 230/230-114, +4 adv, 5800 rpm
You see, the rpm at peak looks like it's related more to cid than the cam spec's. The T76GTS runs out of steam sooner with the bigger engines so the hp peaks sooner. I bet that you'd have to go up to something like 230 on 350 cid or 236 on 383 to get a 6000 rpm peak. At that point, you have to ask yourself, are you helping or hurting the overall combination just to get it to peak at 6000 rpm? Perhaps it would be better to cam if for 5600 to match the turbo the best.
TransAm396 12-17-2006, 11:10 PM its a 355. If a stock cam peaks around 5700 i dont see how a cam this much bigger peaks the same. I was told a 222/222 would peak around 6200.
TransAm396 12-17-2006, 11:12 PM My goal isnt to get the most out of the turbo, its to make the most power I can up to 6k and I dont want to spin past that. (2 bolt studded mains, stock crank)
engineermike 12-17-2006, 11:20 PM I don't think 222/222 would peak that high, even NA. Here's an interesting dyno test for you:
http://www.turbomustangs.com/projectcar/Brent/brentdavisdyno.php
302 cid, 226/226 cam, T74GTS turbo, peak hp at only 5350 rpm. So, less cubes, more cam, similar turbo, and a low hp peak (not to be confused with low peak hp).
I'm running a 224/236 cam and it works quite well. I tried a 226/226-114 and wound up switching back to the old 224/236 cam. I've been itching to try 230/236-114 or even 112, but I dont think it would give me more than 25 hp which is 1 psi boost for me.
That's my recommendation for you. 230/236-114, +4. It will make peak power around 6000 rpm on 355 cid with a T76GTS.
engineermike 12-17-2006, 11:22 PM Don't get me wrong, the 221/221 cam will be a beast, but it will peak around 5200 - 5400 rpm. I just think you'll make more power at any given boost level with 230/236 and it will rev a little higher.
30thTA0525 12-18-2006, 05:27 AM dont mean to highjack but what do you think about a 230/236 112 VS. a 218/225 on a 114 with a P600b on a 383 Mike? those are the two cams that i have
TransAm396 12-18-2006, 06:51 AM Don't get me wrong, the 221/221 cam will be a beast, but it will peak around 5200 - 5400 rpm. I just think you'll make more power at any given boost level with 230/236 and it will rev a little higher.
Oh. I just dont want to bring the car past 6k I know id be leaving power on the table but im concerned with making this motor last a little while and I know I can make more HP if I keep the revs down safer.
RealQuick 12-18-2006, 09:09 AM If a stock cam peaks around 5700 i dont see how a cam this much bigger peaks the same. I was told a 222/222 would peak around 6200.
Stock cam peaks @ 5250rpm...5300rpm when I had full bolt-ons. Just for reference, my 230/236 114LSA N/A setup peaked @ 6000rpm...my new 224/224 cam hopefully will peak around 5600-5800 in a 383ci...I dont know though.
engineermike 12-18-2006, 09:59 AM dont mean to highjack but what do you think about a 230/236 112 VS. a 218/225 on a 114 with a P600b on a 383 Mike? those are the two cams that i have
Superchargers are a little trickier than turbo's. The 230 should peak a little higher due to the IVC being 4 deg later, but there's no guarantee you'll get more hp since it has 15 deg more overlap. In every dyno test I've seen, turbo's seem to make more power with more overlap, but superchargers could go either way.
30thTA0525 12-18-2006, 04:53 PM Superchargers are a little trickier than turbo's. The 230 should peak a little higher due to the IVC being 4 deg later, but there's no guarantee you'll get more hp since it has 15 deg more overlap. In every dyno test I've seen, turbo's seem to make more power with more overlap, but superchargers could go either way.
well i think im gonna take a risk and go with the bigger one.. im gonna give the other one back too the guy i bought the shortblock from i had too decide and give him one of them too sell once i decided which one i was gonna run (he ran the smaller one with the same engine/blower but with better heads at 12psi) i guess atleast it will sound good haha hopefully it will make and much or more power than the small one
TransAm396 12-19-2006, 01:29 AM How about this cam Mike..
220/232 duration @.050
.498/.507 lift w/1.5 rocker .525/.535 lift w/1.6 rocker
114+2 LSA (has 2 degrees of advance ground in).
would something like that work with a turbo or be no good? cuz for the price its almsot worth it being 150$ cheaper for another cam that would maybe give me 5hp
would that cam work for my power range of 550-600rwhp?
engineermike 12-19-2006, 07:09 AM How about this cam Mike..
220/232 duration @.050
.498/.507 lift w/1.5 rocker .525/.535 lift w/1.6 rocker
114+2 LSA (has 2 degrees of advance ground in).
would something like that work with a turbo or be no good?
Expect power numbers similar to the 221/221 cam. The exhaust duration doesn't have a dramatic affect on power on most combinations. However, the lift is kinda' weak, though, which makes me wonder how lazy the ramp rates are.
Mike
rskrause 12-19-2006, 08:09 AM FWIW, the thing about overlap and blowers is a tradeoff. IF you have excess blower capacity (think of an alcohol Hemi), overlap is good as it blows the end gasses clean out of the cylinder. Of course, a lot of fresh fuel and air goes with it (hence the flames). With the small centrifugals we use, you can't afford to blow too much of the charge out the exhaust. Experience shows that for typical setups you want very little overlap at 0.050" and at least 10 degrees more exhaust duration to partially compensate. This leads to relatively wide LSA's (113-116 degrees work best with typical durations).
Rich
TransAm396 12-19-2006, 11:33 AM Expect power numbers similar to the 221/221 cam. The exhaust duration doesn't have a dramatic affect on power on most combinations. However, the lift is kinda' weak, though, which makes me wonder how lazy the ramp rates are.
Mike
Yeah, I was thinking the same thing.You think this cam is capable of 550-600rwhp? Im just looking for something to get me through the year thats very streetable and makes around 550-600rw with the 76mm on 10-12psi
TransAm396 12-21-2006, 01:00 AM ???
engineermike 12-21-2006, 01:51 AM Yeah, I was thinking the same thing.You think this cam is capable of 550-600rwhp? Im just looking for something to get me through the year thats very streetable and makes around 550-600rw with the 76mm on 10-12psi
Well, seeing as how Jeremy made 990 rwhp with a 355 LT1 and a T76GTS with a little 218/218 cam, I think the 220 cam is capable of 600 rwhp.
RealQuick 12-21-2006, 10:31 AM Well, seeing as how Jeremy made 990 rwhp with a 355 LT1 and a T76GTS with a little 218/218 cam, I think the 220 cam is capable of 600 rwhp.
What rpm did Jeremy's peak at?
TransAm396 12-21-2006, 12:21 PM Well, seeing as how Jeremy made 990 rwhp with a 355 LT1 and a T76GTS with a little 218/218 cam, I think the 220 cam is capable of 600 rwhp.
the 220/232? even with the small amount of lift?
If that cam would work, I was looking at the CC305 and it seems like it would work better. Its a 220/230 but with alot more lift. .544/.544(with 1.6 rockers)and its on a 114LSA...would I be better off with that cam?
Roadie 12-21-2006, 01:15 PM If that cam would work, I was looking at the CC305 and it seems like it would work better. Its a 220/230 but with alot more lift. .544/.544(with 1.6 rockers)and its on a 114LSA...would I be better off with that cam?
That's what's in my turbo'd 355 (T-76 Q trim)... no numbers yet though.
RealQuick 12-21-2006, 01:22 PM That's what's in my turbo'd 355 (T-76 Q trim)... no numbers yet though.
pfff...hurry up slow poke.
Roadie 12-21-2006, 02:14 PM pfff...hurry up slow poke.
If work wasn't killing me, I'd probably be done... They need to stop sending me all over the globe. 37,000 frequent flyer miles over the last 3 months...
The engine goes in the car the week after xmas, so I should be ready to fire it up sometime right after the new year.
Pics before coating:
http://www.lt1.org/turboeng1.jpg
http://www.lt1.org/turboeng2.jpg
http://www.lt1.org/turboeng3.jpg
I finally went to pick up the pipes from being coated yesterday morning. I haven't taken any pics after coating yet...
anyway, back to the topic at hand... I think the CC305 will be a good choice for a street turbo setup. I'll hopefully have some numbers for ya in a month or so. ;)
RealQuick 12-21-2006, 02:24 PM My wife would divorce me if I traveled that much ;) I picked up a tig welder...should be here by first week of January. SHould be able to put down cleaner welds now. :p
engineermike 12-21-2006, 10:22 PM the 220/232? even with the small amount of lift?
If that cam would work, I was looking at the CC305 and it seems like it would work better. Its a 220/230 but with alot more lift. .544/.544(with 1.6 rockers)and its on a 114LSA...would I be better off with that cam?
All these cam's you are talking about are in the same range. We've been from 221/221, to 220/232, then 220/230. They are all close to the same duration. I pointed out some very high hp examples using 218/218, 226/226, and my very own 224/236. I bet all of these cams are within 30 hp of each other, with the 218/218 being the weakest and the 226/226 being the strongest.
I want to see some more dyno tests on turbo motors with cams in the 230's, 240's, or even 250's.
Mike
TransAm396 12-22-2006, 12:17 AM yeah ill prolly end up going with a cc305, its got a little more lift than the custom one I was looking at..and its still on a 114LSA
94 NO TOP Z 12-22-2006, 01:28 AM With my 355 PT76GTS with a 218/224@.503" (0.533" with 1.6 rockers) on a 114 at 14psi the HP peaked and was basically a flat line between 5200 and 5800. The torque peaked at 4800 rpm at 660 ft-lbs. This is through patiot 1-5/8" block huggers, 2-1/4" crossover and 3" downpipe. Probably a little restrictive.
We did a couple of runs at 24psi but, we couldn't get the car to hook on the dyno. I am going to try a 224/224 with a little more lift this time around(mainly for the extra lift). I think a cam any were in that range will be fine for a street car.
engineermike 12-22-2006, 01:44 AM yeah ill prolly end up going with a cc305, its got a little more lift than the custom one I was looking at..and its still on a 114LSA
Or, you could get a custom grind from Comp that would be 224/230-114 and the intake lift would be .605" with 1.6 rockers, if you're that worried about lift. I'm using that intake lobe also. BTW, Cam Motion looked at that Comp 3192 lobe and said that it's impossible and doesn't really exist.
http://www.compcams.com/catalog/230.html
TransAm396 12-22-2006, 02:39 AM Well, I can get the CC305 new for 200 whereas a custom cam is 300+shipping..and that extra 100$ can go towards something else instead of 3 or 4 hp. =) Plus im not looking for HUGE power, im looking to make what i got last. =) Im sure it will be just fine going from my H/C car to this. Plus I can feel better shifting by 6,000rpms now. lol
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