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Well I have decided to abandon my Independent Throttle Body setup after much deliberation. A few buddies and me have decided to supercharge the engine instead. I will be using a Whipple supercharger, and I will be buying it come this summer. Here is what I posted over at W-body:
Here is the most recent update. I checked it out, and animul used a 2300AX Whipple twin screw on his 97 GTP. This blower, after looking at compressor maps and such, is very slightly UNDERsized for the L67, and way undersized for the 3.4L DOHC. Even though we are down .4L, .3 after the .060 overbore, due to the 90% volumetric efficiency posted by 4 valve per cyl motors, we need a bigger blower. A typical 2 valve engine makes about 80-85% volumetric efficiency. So I am looking right now for more compressor maps offered by Whipple to see if I can find one. Using a 2300AX, I would be putting Adiabatic efficiency at about 63.5% at any boost from 8-14psi. This is really good for a supercharger. The L67 with the 2300AX sees about 64% from 8-12, 63% at 14, and a max of 65% at 10psi, but is still on the small side.
The Eaton M90, I now believe is one of the worst blowers made. At 10psi, it is only at 42.5% Adiabatic efficiency. This SUCKS. The discharge temp is 65* higher thna that of the Whipple, and it has to spin 4300rpm faster. It also costs 12 more hp to run. Also, it flows 55cfm less than the Whipple. So we have established that Whipple=good.
The max you will see from a Whipple is about 65%. A Vortech S-trim will see about 70%, and a good turbo for a L67 will see 74%. But the advantages of the twin screw design (low-midrange boost, ease of install, reliability, etc) make it a better choice in my opinion.
The next size up is the 3300AX, 3.3L per rev. After studying the flow charts for this blower, it is perfect for what I need. A bigass blower for sure, but perfect. These are my values, using a 3.46L enigne, 7,000 rpm, 90% VE.
Boost(psi)-CFM-Cubic meters-Adiabatic efficiency with 3300AX-AE with 2300AX
8-593-16.8-64%-63.8%
10-647-18.3-64.5%-63.5%
12-701-19.9-63.6%-63.2%
14-751-21.3-63.5%-63%
16-809-22.9-62.5%-62.5%
18-855-24.2-60%-62%
Although they look pretty much the same, my boost line, form 5psi to 20, runs right across the apex's of the 3300's AE. So basically, when the blower is at 9psi, it is at 66%, where as it is at 63.5 on the 2300. So the in-between values are a lot higher. Also the numbers should not be compared. The inlet temp on the 2300 is 20*C, it is 25*C on the 3300. So therefore the 3300 is still more efficient for my purposes, even with hotter air coming in. This blower is perfect for me, but it is hard to fathom having a blower that displaces almost as much as the engine itself in a single rotation. This leads me to believe I have an error somewhere, maybe one of my formulas is wrong, I don't know. The price is $2300 for a 3300AX satin black, $2800 for it polished. I will be going satin, and we will see if I can find it cheaper. www.superchargers4less.com gaurantees that they are the cheapest, and they will beat any price, so I will be using them.
Any more ideas? I also need to look at intercoolers, but in the future since the Whipple doesn't need one as of now. The blower is 6.3" high, and my custom LIM should sit at about the same height as the factory LIM. The factory UIM sits about 5" higher than the LIM, so it should fit under the hood of a Z34, but I doubt it will the Fiero. And with the additional 1-2" height of an A/W intercooler, it surely will not. But this is ok.
*Thx to animul for the EXTENSIVE 2300 vs M90 info*
Here is the most recent update. I checked it out, and animul used a 2300AX Whipple twin screw on his 97 GTP. This blower, after looking at compressor maps and such, is very slightly UNDERsized for the L67, and way undersized for the 3.4L DOHC. Even though we are down .4L, .3 after the .060 overbore, due to the 90% volumetric efficiency posted by 4 valve per cyl motors, we need a bigger blower. A typical 2 valve engine makes about 80-85% volumetric efficiency. So I am looking right now for more compressor maps offered by Whipple to see if I can find one. Using a 2300AX, I would be putting Adiabatic efficiency at about 63.5% at any boost from 8-14psi. This is really good for a supercharger. The L67 with the 2300AX sees about 64% from 8-12, 63% at 14, and a max of 65% at 10psi, but is still on the small side.
The Eaton M90, I now believe is one of the worst blowers made. At 10psi, it is only at 42.5% Adiabatic efficiency. This SUCKS. The discharge temp is 65* higher thna that of the Whipple, and it has to spin 4300rpm faster. It also costs 12 more hp to run. Also, it flows 55cfm less than the Whipple. So we have established that Whipple=good.
The max you will see from a Whipple is about 65%. A Vortech S-trim will see about 70%, and a good turbo for a L67 will see 74%. But the advantages of the twin screw design (low-midrange boost, ease of install, reliability, etc) make it a better choice in my opinion.
The next size up is the 3300AX, 3.3L per rev. After studying the flow charts for this blower, it is perfect for what I need. A bigass blower for sure, but perfect. These are my values, using a 3.46L enigne, 7,000 rpm, 90% VE.
Boost(psi)-CFM-Cubic meters-Adiabatic efficiency with 3300AX-AE with 2300AX
8-593-16.8-64%-63.8%
10-647-18.3-64.5%-63.5%
12-701-19.9-63.6%-63.2%
14-751-21.3-63.5%-63%
16-809-22.9-62.5%-62.5%
18-855-24.2-60%-62%
Although they look pretty much the same, my boost line, form 5psi to 20, runs right across the apex's of the 3300's AE. So basically, when the blower is at 9psi, it is at 66%, where as it is at 63.5 on the 2300. So the in-between values are a lot higher. Also the numbers should not be compared. The inlet temp on the 2300 is 20*C, it is 25*C on the 3300. So therefore the 3300 is still more efficient for my purposes, even with hotter air coming in. This blower is perfect for me, but it is hard to fathom having a blower that displaces almost as much as the engine itself in a single rotation. This leads me to believe I have an error somewhere, maybe one of my formulas is wrong, I don't know. The price is $2300 for a 3300AX satin black, $2800 for it polished. I will be going satin, and we will see if I can find it cheaper. www.superchargers4less.com gaurantees that they are the cheapest, and they will beat any price, so I will be using them.
Any more ideas? I also need to look at intercoolers, but in the future since the Whipple doesn't need one as of now. The blower is 6.3" high, and my custom LIM should sit at about the same height as the factory LIM. The factory UIM sits about 5" higher than the LIM, so it should fit under the hood of a Z34, but I doubt it will the Fiero. And with the additional 1-2" height of an A/W intercooler, it surely will not. But this is ok.
*Thx to animul for the EXTENSIVE 2300 vs M90 info*
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