Pwnage's 383 Build (Pics!!)
10-18-2010, 12:43 PM
#81
Le Mans Master
Yeah, you are right. The porting of his SR and cam choice will probably dictate where the power peak is. The cam choice is a pretty good size (duration) and I would think his home porting will gain him some more RPM than a stock SR, though it is hard to know exactly what will happen.
My combo which was setup for LOW RPM torque (auto-x) with a smaller cam (advanced), base ported SR, etc was making ~360rwhp or so. So remembering that HP=(Torque*RPM)/5252 moving that torque band further up as a larger cam would do I should think he could definitely hit 380-390s.
That said, like I said about dynos before. Jeremy's dyno may say 290rwhp and he'll run an 11.5 or it could say 390rwhp and he'll run an 11.5. Just too much variability to live and die by a dyno unless you are using it comparatively with your self.
P.S. Is the Vette put away in Spokane? I'm from the Tri-Cities area originally and if I remember correctly it is starting to cool off pretty quick this time of year. The Vette loved that cold dense air though!
Either way, can't wait to see what happens!
My combo which was setup for LOW RPM torque (auto-x) with a smaller cam (advanced), base ported SR, etc was making ~360rwhp or so. So remembering that HP=(Torque*RPM)/5252 moving that torque band further up as a larger cam would do I should think he could definitely hit 380-390s.
That said, like I said about dynos before. Jeremy's dyno may say 290rwhp and he'll run an 11.5 or it could say 390rwhp and he'll run an 11.5. Just too much variability to live and die by a dyno unless you are using it comparatively with your self.
P.S. Is the Vette put away in Spokane? I'm from the Tri-Cities area originally and if I remember correctly it is starting to cool off pretty quick this time of year. The Vette loved that cold dense air though!
Either way, can't wait to see what happens!
Last edited by USAsOnlyWay; 10-18-2010 at 12:46 PM.
10-18-2010, 01:05 PM
#82
Race Director
There are some pix of how ported that SR is in this thread:
http://forums.corvetteforum.com/c4-t...se-and-sr.html
http://forums.corvetteforum.com/c4-t...se-and-sr.html
10-18-2010, 02:07 PM
#83
Drifting
Yeah, you are right. The porting of his SR and cam choice will probably dictate where the power peak is. The cam choice is a pretty good size (duration) and I would think his home porting will gain him some more RPM than a stock SR, though it is hard to know exactly what will happen.
My combo which was setup for LOW RPM torque (auto-x) with a smaller cam (advanced), base ported SR, etc was making ~360rwhp or so. So remembering that HP=(Torque*RPM)/5252 moving that torque band further up as a larger cam would do I should think he could definitely hit 380-390s.
That said, like I said about dynos before. Jeremy's dyno may say 290rwhp and he'll run an 11.5 or it could say 390rwhp and he'll run an 11.5. Just too much variability to live and die by a dyno unless you are using it comparatively with your self.
P.S. Is the Vette put away in Spokane? I'm from the Tri-Cities area originally and if I remember correctly it is starting to cool off pretty quick this time of year. The Vette loved that cold dense air though!
Either way, can't wait to see what happens!
My combo which was setup for LOW RPM torque (auto-x) with a smaller cam (advanced), base ported SR, etc was making ~360rwhp or so. So remembering that HP=(Torque*RPM)/5252 moving that torque band further up as a larger cam would do I should think he could definitely hit 380-390s.
That said, like I said about dynos before. Jeremy's dyno may say 290rwhp and he'll run an 11.5 or it could say 390rwhp and he'll run an 11.5. Just too much variability to live and die by a dyno unless you are using it comparatively with your self.
P.S. Is the Vette put away in Spokane? I'm from the Tri-Cities area originally and if I remember correctly it is starting to cool off pretty quick this time of year. The Vette loved that cold dense air though!
Either way, can't wait to see what happens!
The weather has been beautiful up here, and it is still fairly warm. Only 2 nights of frost so far, and 55-60 highs during the day. I'll drive mine until precipitation starts, whether that be rain or snow. Then I am tearing down my engine for a cam, Eddy Hi Flo, home siamesed stock runner install. Maybe some head porting and stainless swirl port valve replacement. Maybe some 1.6 rockers with some guide clearancing to boot.
10-20-2010, 11:05 AM
#84
Tech Contributor
Thread Starter
That sentence makes me giggle inside with excitement lol. Its going to be a beast.
10-20-2010, 12:52 PM
#85
Tech Contributor
Thread Starter
Here is a picture of the rod...I found a shop that knows what they are doing. B and B Racing Engines out of Appleton/oshkosh area. Knew exactly what I was talking about when i mentioned 383, so that's good. Sorry for cell phone pictures...they are from my Droid, supposedly 5mp. You can see the important parts of the pictures. And my lawmower 
and my dads 08 Yamaha V-star in the background. Cool bike.
and my dads 08 Yamaha V-star in the background. Cool bike.
Last edited by Pwnage1337; 10-20-2010 at 02:04 PM.
10-20-2010, 01:55 PM
#87
Tech Contributor
Thread Starter
hahahahaha you spotted that huh 
best 400 dollars i've ever spent. incredibly successful at pissing off my dads girlfriend who thinks i should spend 3 hours mowing the yard with a pushmower. why do that when i can buy Randy and cut the entire thing in 30 minutes at 9 miles an hour.
best 400 dollars i've ever spent. incredibly successful at pissing off my dads girlfriend who thinks i should spend 3 hours mowing the yard with a pushmower. why do that when i can buy Randy and cut the entire thing in 30 minutes at 9 miles an hour.
10-20-2010, 11:35 PM
#88
Le Mans Master
While this build is going on a 383, I'd like to ask about the MAF. So I've read in a TPI fuel injection swap book that the MAF even descreened is only good enough to handle flow requirements up to around 330 hp. Can someone confirm this or dispell it as false? And if false what are the flow limits of the stock MAF?
How well will it cooperate with the 383 even if just a mild version? How about a higher winding one?
How well will it cooperate with the 383 even if just a mild version? How about a higher winding one?
10-20-2010, 11:57 PM
#89
Tech Contributor
Thread Starter
From what I know when the MAF "pegs" (maxes out) the computer goes to a mode where it delivers more fuel based on RPM..which isn't really accurate. I think someone sells a MAF that goes higher than 255 grams/sec, not sure who though. I think this is called VE mode, (velocity enrichment? something like that)
Last edited by Pwnage1337; 10-21-2010 at 12:10 AM.
10-21-2010, 12:47 AM
#90
Drifting
Member Since: Nov 2009
Location: Perth Western Australia
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St. Jude Donor '10
From what I know when the MAF "pegs" (maxes out) the computer goes to a mode where it delivers more fuel based on RPM..which isn't really accurate. I think someone sells a MAF that goes higher than 255 grams/sec, not sure who though. I think this is called VE mode, (velocity enrichment? something like that)
I think I recall someone saying the body of the MAF does not limit airflow up to about 450hp.
VE is volumetric efficiency. You can tune using the PE (Power enrichment) tables past 255 g/s if you have the tuning hardware.
Refer quote from orr89rocz
"You wont discover a choke point with the MAF sensor by looking at graphs of the g/s. The ecm is only going to display 255 gram/sec flow max, but that does not mean the MAF is choked out. It will pass MORE air than what it can measure.
LS1 MAF's are about the same diameter but will read up to 512 g/s i do believe. The ecm and sensor are just calibrated and setup to handle that large airflow
My 383 HSR motor peaked the MAF at 4500-4800 rpm. It read 255 and stopped reading. BUT i made 400whp at 6300 rpm and pulled to 6600 without falling off. 4500 rpm is about where I peaked torque. It was flat from 4000-almost 5000
So the 3" MAF was not a restriction. I changed to a 3.5" setup and it did not help power from what I could see at the track. "
Last edited by Lemme; 10-23-2010 at 07:47 PM.
10-21-2010, 01:41 AM
#91
Tech Contributor
Thread Starter
The 255 g/s is a limitation of the 8 bit combuter. No point going to more than a 255 MAF unless you change to a 16 bit or higher computer.
I think I recall someone saying the body of the MAF does not limit airflow up to about 450hp.
VE is volumetric efficiency. You can tune using the PE (Program enrichment) tables past 255 g/s if you have the tuning hardware.
Refer quote from orr89rocz
"You wont discover a choke point with the MAF sensor by looking at graphs of the g/s. The ecm is only going to display 255 gram/sec flow max, but that does not mean the MAF is choked out. It will pass MORE air than what it can measure.
LS1 MAF's are about the same diameter but will read up to 512 g/s i do believe. The ecm and sensor are just calibrated and setup to handle that large airflow
My 383 HSR motor peaked the MAF at 4500-4800 rpm. It read 255 and stopped reading. BUT i made 400whp at 6300 rpm and pulled to 6600 without falling off. 4500 rpm is about where I peaked torque. It was flat from 4000-almost 5000
So the 3" MAF was not a restriction. I changed to a 3.5" setup and it did not help power from what I could see at the track. "
I think I recall someone saying the body of the MAF does not limit airflow up to about 450hp.
VE is volumetric efficiency. You can tune using the PE (Program enrichment) tables past 255 g/s if you have the tuning hardware.
Refer quote from orr89rocz
"You wont discover a choke point with the MAF sensor by looking at graphs of the g/s. The ecm is only going to display 255 gram/sec flow max, but that does not mean the MAF is choked out. It will pass MORE air than what it can measure.
LS1 MAF's are about the same diameter but will read up to 512 g/s i do believe. The ecm and sensor are just calibrated and setup to handle that large airflow
My 383 HSR motor peaked the MAF at 4500-4800 rpm. It read 255 and stopped reading. BUT i made 400whp at 6300 rpm and pulled to 6600 without falling off. 4500 rpm is about where I peaked torque. It was flat from 4000-almost 5000
So the 3" MAF was not a restriction. I changed to a 3.5" setup and it did not help power from what I could see at the track. "
10-21-2010, 08:44 AM
#93
While this build is going on a 383, I'd like to ask about the MAF. So I've read in a TPI fuel injection swap book that the MAF even descreened is only good enough to handle flow requirements up to around 330 hp. Can someone confirm this or dispell it as false? And if false what are the flow limits of the stock MAF?
How well will it cooperate with the 383 even if just a mild version? How about a higher winding one?
How well will it cooperate with the 383 even if just a mild version? How about a higher winding one?
As far as the tuning fact's, I have no clue.
10-23-2010, 12:57 PM
#95
10-23-2010, 01:47 PM
#97
10-23-2010, 03:08 PM
#99
Remember, when I was doing this back in 93-99 or so, we didn't have all of the self proclaimed internet "experts" that we have today. No one could tell us what we could, or could not do. There were a handful of companies that built good cars. We did not have dozens of thousands of dollars, so we forced to do our R&D differently than it is done today.
We went to the track and did 2 things.
1) Tried like hell to find people that were going fast with these platforms (so we could do what they did). They were few and far between.
2) Use our best judgement, and build the best stuff we could, using the resources we had available. Lot's and lots of parts changing, and subtle changes until we found what worked. Not what "should work", based on computer programs, but data. Specifically, dragstrip data, weather data, reading spark plugs, and a $50 scanner. Actually, it was a $1500 dollar scanner then, but worth $50 or less today.
Another interesting tidbit was the lack of performace tires available. In regards to street tires, a rock hard 16 inch Goodyear gatorback was one of the better choices in 1993. Managed to get a 1.770 60 foot time on a gatorback, before we were forced to come up with an inexpensive, "creative" way to run a sticky radial (remember, this was years before drag radials were intorduced).
Tuning was not done then, like it is now, so we worked around it.
We went to the track and did 2 things.
1) Tried like hell to find people that were going fast with these platforms (so we could do what they did). They were few and far between.
2) Use our best judgement, and build the best stuff we could, using the resources we had available. Lot's and lots of parts changing, and subtle changes until we found what worked. Not what "should work", based on computer programs, but data. Specifically, dragstrip data, weather data, reading spark plugs, and a $50 scanner. Actually, it was a $1500 dollar scanner then, but worth $50 or less today.
Another interesting tidbit was the lack of performace tires available. In regards to street tires, a rock hard 16 inch Goodyear gatorback was one of the better choices in 1993. Managed to get a 1.770 60 foot time on a gatorback, before we were forced to come up with an inexpensive, "creative" way to run a sticky radial (remember, this was years before drag radials were intorduced).
Tuning was not done then, like it is now, so we worked around it.
Last edited by Pete K; 10-23-2010 at 03:28 PM.
10-23-2010, 06:05 PM
#100
Melting Slicks
you don't really need to tune the ecm for nitrous. nitrous is tuned by jets, bottle pressure and fuel pressure.. as long as the car is running fine the nitrous setup isn't way off it isn't going to effect the car negatively as long as everything is working fine and enough timing is pulled out when it being used. ecm tunes aren't really that different from one setup to another.. i think its more of making the injector settings match up to the fuel map then the other way around especially when the power curves are similar as they would be in a LTR setup.