Supercharging a 3.4 DOHC with an M-90

Forever-Fiero · Post by **Forever-Fiero** » Sat Apr 15, 2006 1:18 pm

Hi This is my first Post so forgive me if I do this wromr. :scratch: Im in the process of Supercharging a 3.4 DOHC. This is not an attempt this will happen!! I Have access to a CAD Lazer so cuting out the flanges and all other parts to make a custom lower intake come's EZ!! The computer work is were im lacking!! Im going to use 3.8 sc s2 injecters but will that be enough fuel and flow for a 3.4 to stop the detinatino?? If you know any info or just have a hint or comment please let me Know. Think you, Tony

crzyone · Post by **crzyone** » Sat Apr 15, 2006 2:09 pm

We have discussed this in another thread. I think an Eaton M112 would be better suited for the 3.4dohc, depending on how much power you want to make.

crzyone · Post by **crzyone** » Sat Apr 15, 2006 2:11 pm

Here ya go, found the thread where it is discussed

phpBB/viewtopic.php?t=2156&highlight=m112

Shaun41178(2) · Post by **Shaun41178(2)** » Sat Apr 15, 2006 3:09 pm

slow'n'steady · Post by **slow'n'steady** » Sat Apr 15, 2006 4:14 pm

:rotflmao:

been there, almost did that... was talked into a turbo instead

Forever-Fiero · Post by **Forever-Fiero** » Sun Apr 16, 2006 1:06 pm

Ok I Know its easier to turbo but thats what everybody dose!! Thay start out with a goal in puting a supercharger on the 3.4 DOHC and then get's talked out of it by every one that thay asked. I Know some of you got to be curious on what it will do!!(Not what the paper's say but what it rilly dose) I say overdrive the super. to a 2\1 ratio and if it wants to eat it's self the o well. Ive done the turbo to miny times and I want to supercharge this one!!! I would like to know if the injecters will work!?!? This is somthing i will do. the 3.4 N\A is some what weak on the low end right, and thats were a super. will come in the most! Not on top were you dont need it but on bottem. at 7000.RPM's it will still keep the boost above 0. witch is 100 tome's better them vacing 15. or 20. psi with the N\A's righr?? I Know if you do nuthing but keep them out of vac, it's still a whole new car do to just that!! please let me know if i got it wrong!!

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Apr 16, 2006 1:20 pm

why don't you show us pics of where you are at now in your project.

donk_316 · Post by **donk_316** » Sun Apr 16, 2006 1:30 pm

"Ive done the turbo to miny times and I want to supercharge this one!!! I would like to know if the injecters will work!?!?"

Hold on...you have built alot of turbo engines but you dont know how to size injectors?

This is the WRONG forum to bullshit people on.

I dont even know what your saying in the last few lines of that post.

whipped · Post by **whipped** » Sun Apr 16, 2006 1:47 pm

righr. i tink

:scratch:

Aaron · Post by **Aaron** » Sun Apr 16, 2006 5:18 pm

Forever-Fiero wrote:Ok I Know its easier to turbo but thats what everybody dose!! Thay start out with a goal in puting a supercharger on the 3.4 DOHC and then get's talked out of it by every one that thay asked. I Know some of you got to be curious on what it will do!!(Not what the paper's say but what it rilly dose) I say overdrive the super. to a 2\1 ratio and if it wants to eat it's self the o well. Ive done the turbo to miny times and I want to supercharge this one!!! I would like to know if the injecters will work!?!? This is somthing i will do. the 3.4 N\A is some what weak on the low end right, and thats were a super. will come in the most! Not on top were you dont need it but on bottem. at 7000.RPM's it will still keep the boost above 0. witch is 100 tome's better them vacing 15. or 20. psi with the N\A's righr?? I Know if you do nuthing but keep them out of vac, it's still a whole new car do to just that!! please let me know if i got it wrong!!

Owned by English.

A supercharged 3.4 DOHC is OK, if you use the right blower. The 90 ci blower is not the right blower for our application, it is too small for our volumetric efficiency and RPM. And why would you want to hurt the RPM where this motor really shines at? If you want all that spread of power, get a Northstar, it will have all the top end of a turbo TDC, with all the low end of a blown TDC. Use a M112 or Whipple 2300-3300, then you will provide noticable low end increases, whilst also improving the high end dramatically.

At 5500-6000rpm the vacuum on these motors is just barely below 0, not the 15-20 you quoted. But you had to ask if the 3.4 is weak on the low end? (Of which it isn't btw, making more torque from idle to redline than ANY N/A 60* V6 produced up until now). You don't even have a 3.4 DOHC! Yet you're already talking about supercharging it?

And the top end IS where we need power. Tell me the last time you were racing and used sub 3000rpm. If you can, you need to learn how to drive.

crzyone · Post by **crzyone** » Sun Apr 16, 2006 11:49 pm

Low end torque is only used in 1st gear, and my 3.4dohc had plenty.

Where did you get the idea that they have little low end torque?

Forever-Fiero · Post by **Forever-Fiero** » Mon Apr 17, 2006 1:35 am

I get this from My 93 olds cuttles!! Its a Q car on motor number 2 and is stronger at top end then at lower end. this is the only 3.4 i have to base my real power feal on!! Im not a 3.4 prow by any means. thats why i asked for some help!!! not a bitch bash!! So you think the M-112 is the one to go with over the M-90. I can see your point and thats what im going to go with!! Im not out to dis-clame your know who, Its not ase ez to fined a M-112 but I will!! Think you for your help there!! As fare as the injectors gose its not the flow or psi, its the Ohm defrenc of the 3.4 and the 3.8 ECM!! Not a BULLSHIT, Just the need to know what it will efect!! this is the first GM boost for me!! Ive turboed DSM's 3 times, love what it dose for them but just want to get back to a GM motor!! Its time to bring my Fiero back to life!! Just to see what a supercharged 3.4 will be like!!

crzyone · Post by **crzyone** » Mon Apr 17, 2006 1:46 am

Take nearly 1000lbs off your car and you will get an idea how a stock 3.4 feels like in a fiero. Its quite fast, a high 13 low 14 second engine.

A M112 would be pretty cool, but 100% of the people who have said they were going to supercharge a 3.4 end up changing their minds.

Kohburn · Post by **Kohburn** » Mon Apr 17, 2006 7:14 am

come one guys - your witchhunt smacks of Old Europe - you know, that place you always mock for doing just that?

The Dark Side of Will · Mon Apr 17, 2006 8:59 am

Moderated!

On a serious note, lay off the exclamation point! We can hear you just fine!! It would be easier to understand what you're saying if you proofread what you type, too!!

Just use the same rules for sizing injectors in a forced unduction 3.4 as you would in a DSM!! Are you saying that you turbo'd non-turbo DSM's?!? or that you upgraded turbos on DSM's!?!

Forever-Fiero · Post by **Forever-Fiero** » Mon Apr 17, 2006 5:33 pm

Ok I boosted 1 non turbo with a 14-B and 2 turbo upgrade's to Big 16-G's And its not that i dont proofread my post it's that im just that bad at spalling and know and then I hit the wrong keys. Sorry for the inconvience. On the other hand you say its the weigh of the cuttles that give's the false power feel. Think you for that help! And supercharging this 3.4 is somthing im realy dedicated to doing.

Mach10 · Post by **Mach10** » Mon Apr 17, 2006 5:36 pm

Heh... Watch them pistons!

phpBB/viewtopic.php?t=3177

Indy · Post by **Indy** » Mon Apr 17, 2006 7:11 pm

To answer a question...I believe that the 3.4 DOHC and 3800 injectors are both high impedence type.

The Dark Side of Will · Mon Apr 17, 2006 7:53 pm

The vast majority of production GM injectors are high impedance.

whipped · Post by **whipped** » Mon Apr 17, 2006 8:04 pm

*multiport

Real Fiero Tech

Supercharging a 3.4 DOHC with an M-90

Supercharging a 3.4 DOHC with an M-90

0 is better then vac15.

Re: 0 is better then vac15.