Why did my Z06 dyno so low? Lots of mods, low numbers
09-09-2005, 11:47 AM
#81
Thanks chuck. Is there anyway you can desensitize the knock too? Like i know it cant be knocking that bad so cant be like turn it off? I only ever run 93 octane. I dont know much about cars though, i know on my LT1 the knock was completely desensitzed becuase i had installed custom sidepies that kept banging.
09-09-2005, 01:14 PM
#82
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Originally Posted by Shawn MacAnanny
So what you guys are basically telling me is that my setup is for a stroker or something?
09-09-2005, 01:36 PM
#83
Why cant i just increase the compression with a 408? Cant i get like domed pistons or something? I wanted to get the HPE iron 408 with like domed pistons or something. The heads shouldnt need to be milled with a high CR shortblock. Chuck, what are my options for shortblocks?
09-09-2005, 03:56 PM
#85
Originally Posted by THRLSKR
Shawn -
Forget the IRON 408 - everyone is going Ls2 402 with forged pistons now - this is the best solution but you may have a bore problem with your heads.
Forget the IRON 408 - everyone is going Ls2 402 with forged pistons now - this is the best solution but you may have a bore problem with your heads.
Not true. The 408 is still a popular setup and is cheeper then the 402.
The 4" stroke and added bore will increase compression however is you think your missing power now without the 90/90 it will be a even bigger difference once going 402/408/422/427/ whatever you decide to do.
I personially dont see 480 in your future without more compression, and a 90/90 combo with stock cubes. The fast 90 combo really makes a difference.
Good luck this week finding the power and heal fast.
09-09-2005, 05:06 PM
#86
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Not to mention the 408 will be stronger than an LS2 402. We build 20 408's to every 1 LS2 402. So I don't forsee it taking over the market anytime soon. most people aren't comfortable with the conversion yet.. A 408 will handle more nitrous, and from what I've been told, nitrous might be in this cars future... Definitely go the 408. This setup with a 90/90 setup and a 408 would easily make around 475-500 rwhp. Then add gas on top of it and hold on 
Another option is a 383 if you didn't want to add the extra 75 lbs to the nose of the car. But the bore size of a 408 alone will give you a little more power by increased flow from the heads, not to mention the cubic inch's. So I'd only do a 383 if you didn't want the extra weight.
You could also do a 427. It'll cost around 2700 dollars more than a 408. But I wouldn't feel as comfortable with the same amount of dope on a 427 as you could with a 408 simply due to the sleeved block.
Chuck
Another option is a 383 if you didn't want to add the extra 75 lbs to the nose of the car. But the bore size of a 408 alone will give you a little more power by increased flow from the heads, not to mention the cubic inch's. So I'd only do a 383 if you didn't want the extra weight.
You could also do a 427. It'll cost around 2700 dollars more than a 408. But I wouldn't feel as comfortable with the same amount of dope on a 427 as you could with a 408 simply due to the sleeved block.
Chuck
09-09-2005, 08:17 PM
#87
weight doesnt matter much to me. I'm not into road course racing or anything anyway so i figure another 75lbs for 75rwhp isnt going to make much of a difference. Plus im sure the iron block will sound much nicer with the extra cubic inches.
09-10-2005, 01:53 PM
#88
I just read throught this entire thread and saw 4 things that are a must.
1- you need to notch the pistons so you can:
2- raise the CR a full point with thinner gaskets and mill the heads. 11:5:1 minimum.
3- A fact any dynojet owner will tell you: running a drag radial at low pressure on a dyno can lower the power reading by as much as 30hp. Try normal pressue for an accurate reading just to humor me on one of your pulls. I got this info from James at RWTD by his own test/observation. To say you want to test it the way you drive it isn't testing properly. Just as overinflating is a false dyno measurement, underinflating is just as bad in the wrong direction.
4- get the A/F ratio to 13:1 at the peak HP not 12:1
You clearly have a combo that is meant to spin above 7k for max power and you are using the stock bottom end. That is a bad idea. That cam has a far too high power band IMO. That cam on a 110lsa would be reasonable. You would have had a quicker car with only one mod: the g5x4 cam and everything else stock. Stock Z06's have gotten more power than this combo, cam only. Optimum: Change the cam.
Good luck
1- you need to notch the pistons so you can:
2- raise the CR a full point with thinner gaskets and mill the heads. 11:5:1 minimum.
3- A fact any dynojet owner will tell you: running a drag radial at low pressure on a dyno can lower the power reading by as much as 30hp. Try normal pressue for an accurate reading just to humor me on one of your pulls. I got this info from James at RWTD by his own test/observation. To say you want to test it the way you drive it isn't testing properly. Just as overinflating is a false dyno measurement, underinflating is just as bad in the wrong direction.
4- get the A/F ratio to 13:1 at the peak HP not 12:1
You clearly have a combo that is meant to spin above 7k for max power and you are using the stock bottom end. That is a bad idea. That cam has a far too high power band IMO. That cam on a 110lsa would be reasonable. You would have had a quicker car with only one mod: the g5x4 cam and everything else stock. Stock Z06's have gotten more power than this combo, cam only. Optimum: Change the cam.
Good luck
Last edited by Spinmonster; 09-10-2005 at 02:18 PM.
09-10-2005, 03:39 PM
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Originally Posted by Shawn MacAnanny
Well it's chucks cam so I'd like to see what he has to say about it. We are going to pump the tires up on the next dyno run and to lean it out.
I've got LS1 headed cars making 430+ cam only with that cam peaking around 6400-6500 rpm.
Chuck
09-10-2005, 04:14 PM
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Originally Posted by Shawn MacAnanny
Well the entire cam/head setup is contrary to what i wanted. Fran Schatz picked everything. I had a list of what i wanted installed, he decided none of it was ok so he assured me this setup would make huge numbers on my stock shortblock. I guess he was wrong.
No we didnt flycut the pistons. The first set of heads were milled unbeknownest to Fran and he bent all the valves on the first start up. So we sent out my heads to get them worked, no milling, and it seems to work fine now. I was wondering if they were slighty bent myself.
Chuck do you think that you cam has enough clearance with stock unmilled LS6 heads? Also thanks for the the tuning offer but i live like 2,000 miles away otherwise i would definately take you up on the offer.
No i didnt check fuel pressure. See i paid about $9k to Fran to do this work and have it all tund for me. He promised me the car could go 10s with this setup and that he would have it all dyno tuned and such. I am only 18 years old so when i spend $9,000 it had damn well better do what it's supposed to. I'm just a little dissappointed.
Thanks SS02. I saw your car too when i picked the vette up. Very clean man. Killer setup you're doing too man. My AIM and Yahoo is ShawnMacAnanny if you ever wanna talk.
So the bottom line is the setup i have is crap? I should have gone with 5.3L heads, and a different cam? I wanted the Trex or the G5X3 cam. If i put in an iron 408 like i planned on, what could i expect from that? Would all of my numbers skyrocket?
No we didnt flycut the pistons. The first set of heads were milled unbeknownest to Fran and he bent all the valves on the first start up. So we sent out my heads to get them worked, no milling, and it seems to work fine now. I was wondering if they were slighty bent myself.
Chuck do you think that you cam has enough clearance with stock unmilled LS6 heads? Also thanks for the the tuning offer but i live like 2,000 miles away otherwise i would definately take you up on the offer.
No i didnt check fuel pressure. See i paid about $9k to Fran to do this work and have it all tund for me. He promised me the car could go 10s with this setup and that he would have it all dyno tuned and such. I am only 18 years old so when i spend $9,000 it had damn well better do what it's supposed to. I'm just a little dissappointed.
Thanks SS02. I saw your car too when i picked the vette up. Very clean man. Killer setup you're doing too man. My AIM and Yahoo is ShawnMacAnanny if you ever wanna talk.
So the bottom line is the setup i have is crap? I should have gone with 5.3L heads, and a different cam? I wanted the Trex or the G5X3 cam. If i put in an iron 408 like i planned on, what could i expect from that? Would all of my numbers skyrocket?
Good luck and please dont change the cam or the heads they will both get you to 450 rwhp easily just get the problems fix and you will be happy.
Matt
09-10-2005, 04:26 PM
#94
Hey Matt i turned 18 in March. We're the 2 coolest 18 year olds on the forum. HAha. The car is being picked up Tomorrow so Fran can try to fix all of this for me. I dont plan on changing any of the parts, i really think it's something small like a misgapped spark plugs, knock retard, something to do with the tune. I know i've pulled plugs out before that have been completely closed becuase i guess i bent the end trying to put them into the heads. I'm not too worried. The hard part was coming up with the money. That's over with, it's now just a few little things that need to be fixed.
09-10-2005, 04:41 PM
#95
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If you want the best head, compare runner volume, yours is 234cc and flows 309cfm. AFRs are 205cc runners, and flow high 290s cfm not to mention the better exhaust ports. AFR is a better street head and mine made 440whp and 418 tq, with a baby cam. I made 410rwhp with the same setup using ported ls6 heads. The reason is velocity. The smaller the port the faster the air moves in turn you get a better mixture and a better cylinder fill. The bigger is better is not true, I found that out when I was 18. Put Brodix 335cc runner heads on a 396 in a 67 c-10 pickup. Lost ET mph and HP!!!! Heads were to big for my little big block.
09-10-2005, 05:03 PM
#96
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heads
Originally Posted by roadrash9r
If you want the best head, compare runner volume, yours is 234cc and flows 309cfm. AFRs are 205cc runners, and flow high 290s cfm not to mention the better exhaust ports. AFR is a better street head and mine made 440whp and 418 tq, with a baby cam. I made 410rwhp with the same setup using ported ls6 heads. The reason is velocity. The smaller the port the faster the air moves in turn you get a better mixture and a better cylinder fill. The bigger is better is not true, I found that out when I was 18. Put Brodix 335cc runner heads on a 396 in a 67 c-10 pickup. Lost ET mph and HP!!!! Heads were to big for my little big block.
I disagree with the afr 205 is better. Most of our dealers give us very good feedback. Our ls6 head has been a very consistent 445-475 hp head with a combo like Shawns. There is nothing wrong with his combo.234 cc's is not too large. 205 is very small and may have too much velocity. There is a mishap somewhere in the tune or the way it was dyno'd. The biggest problem I usually see is the selection of inproper lobe designs for certain cylinder head flow values. Too much exhaust duration on a good exhaust port will sacrafice bottom end and average torque. some of these cams out there are way too much foe the exhaust system and flow numbers. A 1 7/8 header is huge for a combo like this. A good collector and a 1 3/4 header would have a broader power band. A good flowing exhaust port should be used to an advantage and should be optimized during "blow down". Our 225 head is like this. 276 cfm at .600 with a pipe, you surely would not want a cam that has over 230 degrees for a 350 inch street car. Shawn, stick to your guns and have Fran figure out where the missing link is. When we did this same cylinder head for Chris at APE (god rest his soul) they would always put down 445 or more on a mustang dyno with your same combo.
09-10-2005, 05:12 PM
#97
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Originally Posted by roadrash9r
If you want the best head, compare runner volume, yours is 234cc and flows 309cfm. AFRs are 205cc runners, and flow high 290s cfm not to mention the better exhaust ports. AFR is a better street head and mine made 440whp and 418 tq, with a baby cam. I made 410rwhp with the same setup using ported ls6 heads. The reason is velocity. The smaller the port the faster the air moves in turn you get a better mixture and a better cylinder fill. The bigger is better is not true, I found that out when I was 18. Put Brodix 335cc runner heads on a 396 in a 67 c-10 pickup. Lost ET mph and HP!!!! Heads were to big for my little big block.
Good luck Shawn I am sure we will make the numbers we want.
Matt
I turned 18 on july 1st.
09-10-2005, 08:35 PM
#98
Yeah Fran keeps trying to convince me that my LS6 intake is the weak link in my setup and i know there are cam only cars out there making the same power with an LS1 intake and stock LS1 heads so it's definately something wrong. I know he'll get it fixed for me though. He's been good to me. He's coming to pick it up tomorrow to fix the alignment and look for things that could possibly be wrong.
09-10-2005, 08:41 PM
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Originally Posted by Shawn MacAnanny
Yeah Fran keeps trying to convince me that my LS6 intake is the weak link in my setup and i know there are cam only cars out there making the same power with an LS1 intake and stock LS1 heads so it's definately something wrong. I know he'll get it fixed for me though. He's been good to me. He's coming to pick it up tomorrow to fix the alignment and look for things that could possibly be wrong.