Speed Density vs MAF
Speed Density vs MAF I am currently building a 441ci LSX motor for my 1993 RX7. The motor will be the new GM motor that is supposed to be released this March. My question is in order to get the most out of this motor what route would you recommend me to go? Here is the run down of my app.
441ci
ETP canted heads
Big cam
Carb style intake
I am trying to find a 105mm TB and intake elbow
60lb injectors
progressed 250-500 shot of NOS.
Now the problem I think I am going to come across if I use a MAF is air restriction because I think the most you can get from a MAF is 85mm, and the TB and intake inlet is going to be 105mm.
Also I have been looking at the Edelbrock intakes and it seems that they are only capable of 600hp?? Is there anyother intakes out there that are capable of 1000+hp??
Thanks
441ci
ETP canted heads
Big cam
Carb style intake
I am trying to find a 105mm TB and intake elbow
60lb injectors
progressed 250-500 shot of NOS.
Now the problem I think I am going to come across if I use a MAF is air restriction because I think the most you can get from a MAF is 85mm, and the TB and intake inlet is going to be 105mm.
Also I have been looking at the Edelbrock intakes and it seems that they are only capable of 600hp?? Is there anyother intakes out there that are capable of 1000+hp??
Thanks
Originally Posted by Bink
Lingenfelter makes a 100 mm MAF. Do a search on their site "100 mm Mass Air Flow Sensor".
And for those of you if there are any as far as Speed Density goes why should I go that route instead of the MAF?
Thanks
I'd go MAF-less. For one packaging will be easier, big cam large motor will dial in better without the MAF's help.
We have also seem big gains with ther restriction removed especially on a 440+ ci motor!
We have also seem big gains with ther restriction removed especially on a 440+ ci motor!
has anyone caught what he is building? a 441 ci motor, canted ET heads, and a progressive 250-500 nitrous shot?
And this is going in an rx7? that car's gonna be a pretzel the first time you launch it!
And this is going in an rx7? that car's gonna be a pretzel the first time you launch it!
Originally Posted by JL ws-6
has anyone caught what he is building? a 441 ci motor, canted ET heads, and a progressive 250-500 nitrous shot?
And this is going in an rx7? that car's gonna be a pretzel the first time you launch it!
And this is going in an rx7? that car's gonna be a pretzel the first time you launch it!
Trending Topics
If I was gonna do that, I would use an aftermarket engine managment system w/o a MAF. I haven't done alot of research but I think that the Big Stuff and the XFI will work closed loop with wideband O2's. THAT IS THE ****! You set the A/F to whatever is desired and it gets it there at the various different driving conditions. MAF not required.
I have an Open Loop Speed Density tune in my car using HPTuners.
I have an Open Loop Speed Density tune in my car using HPTuners.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Yea I was thinkn of going with SD, because the car has a big Harwood custom scoop on it and I felt that if I could just put a filter or screen over it, it would make for a perfect ram air set up...and if I had the MAF it might restrict some of that air flow...
You obviously aren't trying to pass emissions, so don't use a maf. It is just a redundant sensor that adds one more complication to a build such as your's. This is regardless of whether or not it would be a restriction.
for your setup, since it seems to be quite extreme, EFILive's Custom Operating System or HPTuners 1barSD would seem most appopriate. you can go quite crazy with intakes or cams, because when all else fails you can run it in n-alpha.
SD is great because it measures all the properties of air going in (accounting for current conditions so no retunes necessary), without obscuring it's path like MAF does. most importantly for LSx computers, you dont have a 512g/sec limit, which is what MAF forces you to do, and it's very easy to hit with bigger setups even in NA trim.
or just skip all the kiddy stuff and get a standalone like Motec or Autronic
if you want to fully understand SD, here's 10 pages of math, physics and bit of chem explaining where does it all come from and what it can do for you:
http://redhardsupra.blogspot.com/200...ity-works.html
SD is great because it measures all the properties of air going in (accounting for current conditions so no retunes necessary), without obscuring it's path like MAF does. most importantly for LSx computers, you dont have a 512g/sec limit, which is what MAF forces you to do, and it's very easy to hit with bigger setups even in NA trim.
or just skip all the kiddy stuff and get a standalone like Motec or Autronic
if you want to fully understand SD, here's 10 pages of math, physics and bit of chem explaining where does it all come from and what it can do for you:
http://redhardsupra.blogspot.com/200...ity-works.html
TECH Senior Member
Joined: Apr 2004
Posts: 6,157
Likes: 1
From: Texas
Originally Posted by Hodgesz28
The car has a 10pt cage, tubed chasis, 4 link suspension, tubed, and a narrowed ford 9inch..... I really don't think its going to be a pretzel....so either help me out on what my thread is about or stay the **** out.
that sounds bad ***...wheres the pics
i would go maf less on a 1 bar setup
As others said, with that "big cam" and 441, 1-BAR SD is the only way to go. As for your other questions:
105mm Throttle Body = Accufab
100 Degree Elbow = Wilson Manifolds
Other Carb Intakes = GM Perf. Parts
We use all these parts, less the 105mm TB ... we use a 90mm TB. There have been alot of carb intake setups that have exceeded 1000hp, so I am not sure where you got that 600hp limit. Maybe unported?
105mm Throttle Body = Accufab
100 Degree Elbow = Wilson Manifolds
Other Carb Intakes = GM Perf. Parts
We use all these parts, less the 105mm TB ... we use a 90mm TB. There have been alot of carb intake setups that have exceeded 1000hp, so I am not sure where you got that 600hp limit. Maybe unported?
Originally Posted by RedHardSupra
for your setup, since it seems to be quite extreme, EFILive's Custom Operating System or HPTuners 1barSD would seem most appopriate. you can go quite crazy with intakes or cams, because when all else fails you can run it in n-alpha.
SD is great because it measures all the properties of air going in (accounting for current conditions so no retunes necessary), without obscuring it's path like MAF does. most importantly for LSx computers, you dont have a 512g/sec limit, which is what MAF forces you to do, and it's very easy to hit with bigger setups even in NA trim.
or just skip all the kiddy stuff and get a standalone like Motec or Autronic
if you want to fully understand SD, here's 10 pages of math, physics and bit of chem explaining where does it all come from and what it can do for you:
http://redhardsupra.blogspot.com/200...ity-works.html
SD is great because it measures all the properties of air going in (accounting for current conditions so no retunes necessary), without obscuring it's path like MAF does. most importantly for LSx computers, you dont have a 512g/sec limit, which is what MAF forces you to do, and it's very easy to hit with bigger setups even in NA trim.
or just skip all the kiddy stuff and get a standalone like Motec or Autronic
if you want to fully understand SD, here's 10 pages of math, physics and bit of chem explaining where does it all come from and what it can do for you:
http://redhardsupra.blogspot.com/200...ity-works.html
Christ almighty thats some badass info thanks a hell of a lot!!!!!
As far as where I got the 600hp recommended intake was the edelbrock
victor jr.....
and pix I will get you some ASAP!
Thanks now where do I go about buying this 1 bar SD? And is there an entire computer harness that I can buy to run all of this?
Both HP Tuners & EFILive offer 1 bar SD custom operating systems that add a ton of functionality.
Here is some info on ours http://www.hptuners.com/forum/showth...newpost&t=8632
It just uses the stock PCM & adds a few tables as well as makes the current tables more functional.
Here is some info on ours http://www.hptuners.com/forum/showth...newpost&t=8632
It just uses the stock PCM & adds a few tables as well as makes the current tables more functional.
Originally Posted by jeffstar
Go SD for sure, that's how my car is set up. I love it 
Do you feel like you gave up anything, by going SD ?
How come more "Pro" tuners don't go SD ?
I envy your combination,
Have you dynoed yet ?
How come more "Pro" tuners don't go SD ?
Originally Posted by SERIALPIMP
Do you feel like you gave up anything, by going SD ?
How come more "Pro" tuners don't go SD ?
I envy your combination,
Have you dynoed yet ?
How come more "Pro" tuners don't go SD ?
I envy your combination,
Have you dynoed yet ?
I gave up the VCM's ability to try to correct things with a sensor that doesn't cope well with low speed/choppy air flow.
I gave the time it took to learn, test and manage the entire setup.
I gave up roughly 300 dollars for my wideband setup.
So yes, it did cost some extra money and it did take more time but the results are great!
From what you have said, and what others are saying it sounds like SD is the way to go,
Your White TA and your LT1 ran hard,
And while past performance is not a promise or guarantee of future performance I see a trend.
Can you recomend some specific reading for understanding SD tuning ?
I understand the parts and sensors and what role each play, but have never approached or thought about tuning at all, I worked as a tech at a dealeship for a while, and we never got into any of that.
Your White TA and your LT1 ran hard,
And while past performance is not a promise or guarantee of future performance I see a trend.
Can you recomend some specific reading for understanding SD tuning ?
I understand the parts and sensors and what role each play, but have never approached or thought about tuning at all, I worked as a tech at a dealeship for a while, and we never got into any of that.