I have a oportunity to purchase a 3in LS-1 maf and Translator. I was under the impression that the LS-1 units were 3 1/2in. Am I wrong on that? I also need your opinions on getting a 3in instead of the 3 1/2. What do you think the performance limit of the 3in is? Thank you all again.
Kevin Smith had this to say on the mailing list:
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Gary,
You are correct, the LS1 MAF is 3.5". Could be an LT1 MAF if it is only 3". My opinion would be to go with a 3.5" over a 3" (that's what I did) as there is only a few bucks difference in price, plus I've heard that the developer of the Translators recommends the 3.5". As far as performance limits are concerned, I honestly couldn't tell you any personal experience -- but I have heard of quite a few guys going with the 3" initially and then switching to the 3.5". Also, heard that many of them use the 3.5" with step down hoses and 3" ducting.
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Now it is Dean talkin'. :-)
The 3" MAF is from the mid-late 90's Impalla SS LT1.
A guy in AZ flowed various MAFs is various configuration (w & w/o screens, box stock, ported) several years ago and posted the data to tb.com, but unfortunately all that data was lost when the servers died in 2002. Though I didn't keep a copy of the data (dang it), I kinda recall the flow limitation of the 3" equating to a couple hundred HP worth of air more than the stock block could handle. So if your deal includes the 3", that's fine, IMO.
A separate thunk, although the 3.5" can flow more, if you are choking it down to 3" piping, wouldn't that negate a majority of the gain over the 3"? Also, by chocking it right at the MAF, undesireable turbulence may cause irratic MAF reading... not saying it will, but in my head, that's what I'm thinking.
Dean
Just for grins, I ran some numbers. The 3" LT1 is 7.07 sq/in. The 3.5" LS1 is 9.62 sq/in. The difference is, the LS1 is 26.5% greater in area. I seem to remember Kirban's had 3.5" pipes to go with the larger MAF. Check it out. Also if you're getting your MAF and Translator from Ramchargers, ask Mike where to buy your pipes if he doesn't stock them.
I happen to have a saved copy of the flow data Mike Licht posted back in 1998. See bleow:
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Date: Mon, 08 Jun 1998 15:51:55 -0400
From: mike@modernmusclecar.com (Mike Licht)
Subject: MAF Translator
With the demise of the factory MAF we got back to work on this project. The original 3" and 4" sensors we were going to build are officially dead. The company that was calibrating them (Pro M / Best Products) cannot do 2 sensors the same (1 or 2 run good and 20 run very bad) after a year of them putting me off and blaming everyone but themselves it is now clear that they cannot do this job. The good news is that the new "MAF Translator" will be ready to ship in about 30 days. This unit will adapt the GM 3" sensor from an Impala SS or the 3 1/2" sensor from the late F-body and recurve it for use on the GN. These unit provide more airflow, better range, and more performance than stock. A chip upgrade and a Scanmaster upgrade will be available that will allow the computer to read and use data to 512 G/Sec, This will help stop a lot of high end lead out, caused by the sensor being out of range. When the stock sensor hits 255 it can no longer measure air and cannot tell the computer to add more fuel. Another future product will be available (plugs in to existing box) that will allow idle A/F adjustments. This product will sell for $179 and the same unit will support both sensors by the use of a dip switch. Sensors will also be available through us or GM, we will provide proper part numbers. The 3" unit can be bought for under $100.
We have been driving these around, they work great and we are taking orders now.
I was playing on the Superflow 600 and flowtesting MAF's and here is some data:
Stock MAF w/ 1 screen = 687 cfm
Stock MAF w/ no screen = 809 cfm
3" Impala SS MAF stock = 772 cfm
3" Impala SS MAF w/ no screen = 875 cfm
The pressure drop and turbulence on the Impala meter is lower as well. The 3.5" F-Body meter will get tested next but I suspect big numbers from it, ran out of time today. The MAF translator will have 4 MAF curves built in for either sensor with and without screens.
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Right on Freddie!! I'll save this one. :-)
Dean