Supercharging and compression - Ford Mustang Forum
 
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post #1 of 13 (permalink) Old 02-27-2010 Thread Starter
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Supercharging and compression

I recently had a motor put together for my Cobra. I always intended to put a supercharger on it. I am now being told that I shouldn't do it because when I had the motor built, I had the compression raised to 11:1. The bottom end is built pretty well. It has a forged crank, Manley rods, CP pistons and ARP studs. The question is can I supercharge this and what do I need to do what kind of boost could I get without running race gas all the time. I found a Kenne Bell top mount supercharger for it and that is what I plan to go with.

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post #2 of 13 (permalink) Old 02-27-2010
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you could supercharge it, but you are going to have to be wary as to how much boost you run. high boost and high compression can lead to detonation, so just keep the boost down and watch out for detonation. you of course are going to have run the highest octane you can find.


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post #3 of 13 (permalink) Old 02-27-2010 Thread Starter
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I really didn't want to go higher than 93 with octane boost.
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post #4 of 13 (permalink) Old 02-27-2010
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Man, doesn't sound like a good combonation at all. Just had a TVS blower put on mine and they dropped the c/r to 8:6. Even with out a blower and todays gas, you could be in trouble fast.
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post #5 of 13 (permalink) Old 02-27-2010
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11:1 you still might want to run race gas man thats some high numbers

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post #6 of 13 (permalink) Old 02-27-2010
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it would be like a time bomb ticking ready to explode !!!!!!!!!!!!!!!!!

thats to much compression....

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post #7 of 13 (permalink) Old 02-28-2010
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11:1 with a supercharger will blow up in a hurry even with race gas. You should've done your homework before selecting that compression. Even n/a that's pretty high for pump gas and will need to have a very good tune to be safe.

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post #8 of 13 (permalink) Old 02-28-2010 Thread Starter
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I was wrong. After doing some checking, the compression ratio is actually 10.8:1 not that that is going to help significantly with what I want to do.
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post #9 of 13 (permalink) Old 02-28-2010
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Your OK with that compression! Lots of Cobra guys are starting to go from 8.5-9.0 to 10-10.5, when your not on the Boost an 8.5 motor is gonna be lacking in the power dept.. I went with a Manley piston that has me a shade under 10! I know guys running 23 degrees spark advance on 93 octane with Eatons!
You should be OK with spark advance in the high teens and the fuel tables set fatter than normal like 11.0 instead of 11.6! Your close to me who built your shortblock? Is the same place gonna do the supercharger? And what year Cobra do you have?

99 SVT Cobra-Teksid.020(284ci)
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post #10 of 13 (permalink) Old 03-02-2010 Thread Starter
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Jay at Real Street Performance in Longwood Florida. Nelson Competition did the machine work. He used to work at Lamotta Performance and started his own shop. I don't think I am going to have him do the supercharger because when he built my motor it was three grand more than what he told me. He did a good job but the price change left a bad taste in my mouth for his shop.
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I hate places that do that, agree on a price and get it in writing!

99 SVT Cobra-Teksid.020(284ci)
Stock HCI,Manley Pistons & H Beam Rods
Polished Vortech V-2,Reichard 3.10/6.75ATI(14lbs Boost)
GodSpeed SpecV Intercooler,60's,Twin Aviator's,
04 SVT Tank/Twin Hat,SCT-BA5000,BF IRS Brace
MPH Powerpipe,ProCharger BPV,
Mac O/R H & 2.5 CB
Vogtland Springs,Bilsteins,MM CC Plates,Steeda Tri-Ax,MT ET Streets
Home of Worlds Fastest All Ford Outlaw 10.5 Car 4.03/200.80 Fordspeed Racing
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post #12 of 13 (permalink) Old 04-13-2010 Thread Starter
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Re: Cobra.‏
From: <img id="P___2082481286" webimdisplaystyle="inline" style="display: none;"> [email protected] Sent: Tue 4/13/10 4:37 PM To: Jay Meagher ([email protected]); Me ([email protected])
I sold it and the in invoice it said competition head job. I assumed that was part of it for $1100. I believe it was briefly mentioned that I wanted it done. Beyond that I told you the motor made a slight clatterring noise from the time I put it in. It also had a lite vibration at around 1200 rpm's. I know you said bring it in and you would look at it but I wasn't happy with it and after having the motor out 3 times I was tired of dealing with it. Also I don't think I said anything bad, just stated that it was way more than we talked about and that I wasn't happy with it. I still owe you $500 which I intend to pay when I get out of a financial slump. Should be in a few weeks.Sent on the Sprint® Now Network from my BlackBerry®
From: Jay Meagher <[email protected]>
Date: Tue, 13 Apr 2010 16:17:55 -0400
To: John Gebhardt<[email protected]>
Subject: Cobra.


https://www.allfordmustangs.com/forum...mpression.html

As far as the CR, keep in mind your plans changed from NA to blown in the process. If the engine was going to get boost it would have been 9.1



I don't know that thin slicing really does the situation justice. I did the job as cheap as it could be done. Clearly if I thought bottom line was more important than quality I would have handled it differently. I did take all I could off your invoice, that included any of my time I had in the job.


I did spend a few minutes talking to a guy in Tampa the other day about the car and told him you were a straight up and honest guy.


You may want to take the "fully ported" off your car add as just a valve job and springs.


Thanks

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NICE letter, DON't give that clown any more business! If you need work done in the future my good friend Joe Bonzcek owns FordSpeedRacing here in Clearwater, getting ready to install my Vortech there next month (Hopefully, haha!)
FYI they build and race Very Fast Cars and their labor pricing can't be beat!

99 SVT Cobra-Teksid.020(284ci)
Stock HCI,Manley Pistons & H Beam Rods
Polished Vortech V-2,Reichard 3.10/6.75ATI(14lbs Boost)
GodSpeed SpecV Intercooler,60's,Twin Aviator's,
04 SVT Tank/Twin Hat,SCT-BA5000,BF IRS Brace
MPH Powerpipe,ProCharger BPV,
Mac O/R H & 2.5 CB
Vogtland Springs,Bilsteins,MM CC Plates,Steeda Tri-Ax,MT ET Streets
Home of Worlds Fastest All Ford Outlaw 10.5 Car 4.03/200.80 Fordspeed Racing
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