UPDATE PAGE 6 !!! 402/afr/fast 102 combo Nitrous results = 8xx/8xx
08-20-2011, 03:13 PM
#43
FormerVendor
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Not to hijack this thread but since I posted here, I've gotten a few PM's regarding my statements about underdrive pulleys. I'd like to say that I don't believe an underdrive pulley will damage your stock or bolt on engine, but in a built motor, especially long stroke high RPM build I do NOT recommend their use. Here is a technical article from ATI's website which is written Steve Dinan of Dinan BMW. I know some people might think its biased but he is not affiliated with ATI and if you do a little research you'll find all of the information to be true.
http://www.atiracing.com/products/da...mper_dinan.htm
I hope this helps.
Shane
http://www.atiracing.com/products/da...mper_dinan.htm
I hope this helps.
Shane
08-21-2011, 01:32 PM
#46
IMO, you have too much exhaust overlap for the flow properties of that cylinder head....your potentially losing some of the next fresh intake charge right out the tailpipe.
Unless it was a dedicated nitrous engine I would say you could scale the exhaust back at least eight degrees. A small forward split (2-4') might have been a better choice increasing cylinder pressure, torque output, and potentially making more power everywhere.
Was Geoff under the impression you were going to be spraying the car or possibly using a different head?
I would also encourage either getting to a track (to see what the car traps) or getting on a different dyno to get another data/reference point concerning the actual numbers (unless you know the dyno you tested on based on other cars results and their performance at the track). Did we ever nail down the type of dyno this combination was tested on?
I would be curious how much cranking compression this engine has also....I sense its lower than it could have been based on the cam but your static CR plays a big role in that as well. Its kind of a good indicator of how well you nailed the combination based on your valve events etc. Very low 200's is optimal on pump gas IMO (with a spot on tune....91 octane applications more on the ragged edge there)....don't forget this whole game is all about developing the most cylinder pressure possible.
-Tony
Last edited by Tony Mamo @ AFR; 08-21-2011 at 02:07 PM.
08-21-2011, 02:31 PM
#47
Staging Lane
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Yes it was spec'd for n20, I can't believe I left that out. The type of dyno that was used was a dynojet. I didn't go to the track but I messed around with brothers car last night which has proven it's self weekend after weekend at the track. He is running high 6s in the 1/8 I'm not sure what that would be in the 1/4 but I think it's high 10s. His setup is cam/boltons, built auto with 3500 stall and a 175shot He made 368 on 2 diff dynos na unlocked. We went from 60-110 3 times and everytime I inched on him to about a fender to 3/4 of a car. Last night he ran a 408/afr/solid roller ford that made
510rwhp, which both cars were setup up for a dig an that's what they did but he pulled 2 cars.. So idk maybe my numbers were not telling the true story.
510rwhp, which both cars were setup up for a dig an that's what they did but he pulled 2 cars.. So idk maybe my numbers were not telling the true story.
08-21-2011, 06:05 PM
#49
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I would think 1 7/8" headers and true duals along with a set of 3.73 gears would make you perfectly happy. And would shoot you over 500 rwhp for sure. I wouldn't worry so much about the cam. No I don't have a shop, no I'm not some net expert, but I've seen enough combos to realize a cam is a cam. You've got the lift and duration needed to make 500whp and I doubt tinkering with the valve events a little are going to "magically" gain you 40 hp at the wheels, man.
08-21-2011, 07:21 PM
#50
No I don't have a shop, no I'm not some net expert, but I've seen enough combos to realize a cam is a cam. You've got the lift and duration needed to make 500whp and I doubt tinkering with the valve events a little are going to "magically" gain you 40 hp at the wheels, man.
Wow.... That is all I have to say..
08-21-2011, 08:18 PM
#52
TECH Apprentice
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I second that motion.
A cam is not just a cam. It's about combo, how you built it and for what purpose. Now in this case, we know a bit more with the cam specs and nitrous build aspect. If the motor was built for nitrous then he might not make the 500 mark very easy to get. A big cam, ring gaps, etc for a big nitrous shot, you are surely going to give up some NA performance.
A cam is not just a cam. It's about combo, how you built it and for what purpose. Now in this case, we know a bit more with the cam specs and nitrous build aspect. If the motor was built for nitrous then he might not make the 500 mark very easy to get. A big cam, ring gaps, etc for a big nitrous shot, you are surely going to give up some NA performance.
08-21-2011, 11:08 PM
#56
Not to pat myself on the back here, but my build is set up for N20. Rings are gapped wide for the 300-500 hit I plan on putting on this motor. Again it is 11.14-1 cr, hyd roller, 418 with 1 3/4 - 1 7/8 headers, box stock AFR 225's, not to mention the 245/260 cam that is in it. I know it is not optimal for a NA set up, but I didn't build it for that. I still made 521rwhp through a 4L80E with a truck 12 bolt, 4.56's and heavy 315/60/15 drag radials.
Just putting it out there. N20 set ups can make power NA as well.
08-22-2011, 05:18 PM
#58
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Don't get all bent out of shape, man, I'll explain. I just meant I don't think that the cam in the OP's ride is TOO big as pointed out earlier in this thread. Or, in other words, the cam is not holding the car back from hitting 500whp. All I meant is I've seen several combos with big cubes and good heads running similar spec cams (240's dur .600+ lift) that have easily passed 500whp. Of course everyone knows all engine builds will differ due to the infinite numbers of variances in peoples motors. That's all I meant to say and I knew a few of you guys would take it out of context.
08-23-2011, 12:07 AM
#59
Just curious, if you "knew we would take it out of context" why write it that way? You made it sound like any cam, big or small would make good power. You can have a 24x/24x cam in a motor and have it perform poorly just the same as a 22x/22x cam. It's just easier to mess things up with the big one 
08-23-2011, 05:29 AM
#60
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What you "meant" to say was clearly written, and comically wrong. Bigger primaries and Dual, and lower gears is all he needs, followed by this ridiculous, outrageously flawed logic: You've got the lift and duration needed to make 500whp and I doubt tinkering with the valve events a little are going to "magically" gain you 40 hp at the wheels, man.
I would run from this thread as fast as I could. I mean, how can you even clean that up for it to be even remotely acceptable?
I would run from this thread as fast as I could. I mean, how can you even clean that up for it to be even remotely acceptable?