Any experience with supercharged SBF motors in a GT40?

OK, I'm a newbie, but I've been reading the forum for quite a while. I did a search for "blower", "supercharger", "supercharged", and "forced induction" and came up with nothing. I am planning on using an SBF, most likely a stroked version of the 302 (331 preferred over the 347), and would like to use a centrifugal supercharger. I have yet to see a post regarding anyone using this combination in a GT40 kit. Does anyone have any experience with this combo, or, perhaps more likely, is there a reason I need to forget about the blower? I do know some kits include brackets to relocate the alternator, so I can see that there might be space issues (however, if the engine bay is big enough to hold a Ford FE or one of the Ford modular motors, there ought to be space for a centrifugal blower, it seems).

If anyone can help me with this issue, I sure would appreciate it. I am in the process of rebuilding a couple of SBF motors at this time and I don't want to invest in a blower (ala Vortech, etc) if it is going to be unusable.

Thanks, guys!

YD,E./PNB

Doug

I haven't seen any replicas yet with a blower.
Reason is space in the area where centrifugal blower is usually located is very small since engine is set so close
to the firewall. Of course where there is a will, there's
a way, and I have no doubt it could be done with a lot of custom fabrication/engine placement.

There's actually been more talk about using a Roots blower,
particularly with the Mod motor as done in the new Ford GT.
That's more likely to happen as people want to to copy
the new Ford's sexy engine.

I believe there are a couple replicas running a turbo...
but your question specifically was about a blower.
Regards

MikeD

Thanks, Mike. I suspected as much--with everything that ends up in that engine bay, I would rather save room for an A/C compressor than a centrifugal supercharger. I happen to like the idea of a Roots blower and I read the Ford Modular Motors forum, too--those good ol' boys report some pretty significant figures when they tie a blower on top of that big, wide mod motor.

As of now, I think I'll go for more displacement rather than try to get a Vortech in there. I want my first build to be pretty straight forward, not a fab nightmare.

I really appreciate the input.

Doug

Hi Doug,

The great thing about these cars is each one is a dream realized. Anyone who's built one can attest to the blood, sweat and tears to get it takes to get one done. The results are worth it!

Everyone has there own idea about how to equip a car, so whatever you ask for opinions on, you'll get a responce.

Then there's the personal perspective, for me a supercharger isn't the best way to go for high horsepower for the money or complexity that comes with it. Not to mention heat and noise.

Nothing else sounds like a GT40, no superchager required Go more cubes and keep it simple. You're in for a helluva ride... enjoy

Do your search again and pay careful attention to the dates. A search of blower with results newer than 5 years old turned up 164 hits.

Ron

I built a 1988 Mustang 5.0 engine thatI did a lot of work on the engine. I did a lot of port work to the heads and had the intake extrusion honed. The pulley combo I used ended up giving me about 9 lbs. boost. At about 3000RPM the engine really came alive and the car was wicked fast. A very good street racer!
My Gt40 is unblown, but is faster than my Mustang was. A 2400lb. car with about 400HP works real good.

Vic

Thanks, Ron. My mistake was limiting my original search to posts within the past 4 years, not 5. I'm still learning to use the search function, so every hint helps!

I share your disappointment the SBF hasn't been fitted for a Roots type blower (meaning similar to the one on the T-Bird S/C). It seems such a shame--I suspect the SBF is the second most utilized engine overall, right behind the SBC, so it makes sense that the demand is there. A low profile blower on or integrated into a dedicated manifold could be made to fit in our car of choice, IMHO.

Does anyone else have any suggestions or comments? It's true anything is possible, it's just that since this effort will be my first build I don't want to have to chop into bulkheads for room, to say the least. Still, I like the idea--perhaps if a builder were willing to custom build the chassis with room in the bulkhead for the blower???? Just wondering.....

We newbies really need the help that you with the experience provide in this forum--Thanks, again!

YD,E./PNB

This is the space on an ERA. (That's a special short water pump too.)



It seems to me that if you want to be foolish, there's much more room for turbochargers.

B&M used to have a blower for the SB Ford, but it would not fit in a 40. I really do think there is a market for a Tbird SC type Eaton manifold and kit for the SB Ford. Hell, if I had time I might be interested in making one - I did go so far as to acquire a 3.8L blower manifold to look at while thinking about doing it.

There would be a market for it because you simply can't beat a positive displacement blower - Lysholm, Roots, Screw, etc. Those centrfigual blowers are okay, but they don't provide that proper supercharged feel.

If you are using a SB Ford in your build then a centrifugal is, I think, the only thing you'll be able to fit if you must have a blower. You'll be able to fit it in there, you'll just need to fab all the brackets etc. to mount it. Use a serpentine front dress with the 94-95 Mustang style water pump and you'll end up with a front dress shorter than what Bob describes without special pumps so you can get off the shelf bits and pieces.

Use this kick ass alternator/water pump pulley combo shown here:

http://www.gt40s.com/ubbthreads/showflat.php/Cat/0/Number/70718/an/0/page/0#70718

And I know you'll have room for a blower. I saw this at Fran's a few weeks ago and was impressed.

More importantly though, if you use one what sort of fuel injection manifold will you use? One of the short runner types or "bread box" style are small and compact and might be about your only option. Having one made that would accept the air from the rear might be a good idea as you could route the blower discharge tube around to the back. Front input would be hard, and side input might run into trouble with the clip.

Thanks for the input, Bob and Ron.

Bob--your point is well taken--I'm not sure I do want to be foolish. I've spent quite a bit of time cruising through all the tech posts and more than one post has suggested that it is better to use a naturally aspirated motor and put the extra $$ into a good LSD transaxle, etc. From a simplicity standpoint that sounds good--less to break, need maintainence, etc. Still, if I am unable to resist these self destructive urges, it is nice to know that there are kits out there that will allow me to embarrass myself. BTW--you would not believe the amount of time I have spent reading all the info on your website!

Ron--what a wealth of information you are! Re: the EFI question you posed, one of the Cobra manufacturers has started marketing a system that uses a modified Edelbrock single plane manifold plumbed with fuel rails and using a 1000 CFM throttle body. The throttle body had sealed bearings so that it could stand the positive pressure of a forced air system. The system also includes an stand alone electronic control system. The photo I saw in one of the kit car mags showed a compact system that looked to be shorter than a carbed system w/air cleaner. I, too, like the positive displacement blowers, and particularly since the manufacturers seem to have tamed the whine a bit. I judge from your comment "if you must have a blower" that you may think this is inadvisable, too. Believe me, there's no ego issue here--I'm open to any and all input. My end goal is to have a car I can spend my time washing, waxing, and most of all driving. The old adage "there is no substitute for displacement" may eventually rule here, but the thought of having a blower chugging away right behind my right ear sure is enticing. One thing is for sure--the SBF can be built for whatever power level I want in a naturally aspirated form. I am keeping in mind that this will be my first build, so simplicity may eventually win out here.

Please keep the comments and suggestions coming, guys. Right now the block is sitting at the machine shop, so the next decision is pistons--I don't mind waiting for that decision if there is more input from anyone else.

YD,E./PNB

Doug, if you are worried about whine, don't be. That will be the least of sounds in a GT40. Besides, the blower whine is all apart of the experience of a blower motor, music.

You don't need a blower in a GT40. At 350-400 hp naturally aspirated it'll be plenty fast. At higher hp levels it is just bragging rights which very few cars are setup properly to handle. Sort of like the wide flairs and superwide tires on the rear - I'll bet you a Ben Franklin I can setup a better handling track car on symmetric race rubber without all that - it is just some folks prefer the flairs and tires for looks.

I've been kicking around the idea of building a similar mid-engined but related car to the 40 and my first impression was to put my 530+hp Ford engine in it. Now I think I'll be much better with a 300hp motor - much more drivable on track I'd imagine, so if I do the car I'll go that route I think.

And that should be left ear, hopefully you are considering building a proper 40?

Now, that's what I like--honest, straight from the hip, realistic advice! Thanks, Ron! It's unanimous now, so I can forget the blower. I like that--like I said, less to need attention! In fact, it doesn't even look like I need to go for a killer SBF build--just a moderate boost in power. That sounds even better--more reliability! I can still use the Edelbrock based EFI system--in fact, with an oval air cleaner it is hard to see the fuel rails, so it will look just like a carb'ed motor to the uninformed. The feature mentioned that they were able to get the 302 to much higher revs than with the stock type FI manifold (I think they mentioned 6500 RPM). As a kid I had a 64 Fairlane with a stout 289 and I fell in love with the sound of a high winding small block--looks like history will repeat itself.

Advice taken and decision made. I'll call and have the machine shop order the higher compression pistons and forget all about the blower.

You don't know how much I appreciate the help, guys. It's nice to deal with a group that seems to be united rather than divided.

As for which ear, well, this will be a street car, not a race car, so I am going to do a left drive build. Sorry if I disappointed you, but driving in the Houston traffic would be a real task with a right hand drive!

YD,E./PNB

Ron, your statement about 400hp and fat tyres etc is 100% correct /ubbthreads/images/graemlins/beerchug.gif---could we do that in neon lights /ubbthreads/images/graemlins/1poke.gif ( so we don't have to keep repeating it) /ubbthreads/images/graemlins/flehan.gif /ubbthreads/images/graemlins/grin.gif

Glad I could help. We could make it a global annoucement?

Seriously, you want to be able to drive and interact with the car on track and if you are timidly driving around at 1/2 - 3/4 throttle you are not getting a good driving experience and are not going to be able to push the car to the limits. If you can't push it, you can't learn to drive it well.

I really thought to put the motor I've got in the garage into this car I'm contemplating building, but since I want it to be a very capable track car for my skills I feel backing it off would really allow that to happen.

Doug, get yourself a nice and crisp 350-400hp motor, good compression, mid-upper RPM bias, and you'll be happy. And, you'll be faster on track I bet, aleibt with less bragging rights, than the 500+hp motored cars. Now if street talk is what you are looking for you might have to re-think, but remember - just get the motor in and driving, you can change that later.

Ron

If not in neon lights or as a global announcement, how about in the FAQ section? I know it is not really a "frequently" asked question, but as a newbie I can attest to the fact that the FAQ's were the first thing I read. If others follow this practice, perhaps the Q might not be asked again, or the answer need repeating. Just a thought....

Ron, your comment regarding track use is well noted--I can't imagine anyone building a GT40 kit and not wanting to drive it in a spirited manner. It makes sense to "test the limits", so to speak, so one knows where not to tread. We all know that the street is not the place to test limits.

The decision is to build a naturally aspirated 302 based small block--not a hard decision since there was not a single post that wholeheartedly recommended the blower. It is hard not to notice that at some of the events sponsored by manufacturers and magazines the small block Cobra replicas are often qicker than the big block cars. I want to move the car, not burn up tires. I have 3 years to build this motor before I can actually order a kit, so that ought to give me plenty of time to solicit advice in the tech forums. I do know it will be slightly oversize, although I don't want to go to the max available in a stroker crank b/c I want long term reliability. What I will do is build it with only the best parts available--forged crank/pistons, H-beam forged rods, roller cam/rockers, etc.--which reminds me, Dove sells an aluminum alloy block w/cylinder sleeves that is represented to have the potential for 380+ CID, as I read their website. That sure is enticing from a weight standpoint, since these GT40's are so light. Yet another reason to not need a blower to make respectable power--no substitute for displacement. It sure bears further investigation, IMHO.

BTW--if anybody is interested in that Edelbrock manifold based EFI system, it's marketed by Quality Roadsters (and maybe others)--check this link: http://www.mass-floefi.com/. They weld injector bungs onto a Victor Jr or Torquer single plane manifold and use a 1000 cfm dry flow throttle body with a GM MAF sensor, and if you are building a system that already has Ford ECI there is an adaptor to convert the GM MAF signal to a format the Ford system can understand. Otherwise, they also sell it with a stand alone EFI system for a few more $$. It looks like a simple system and IMHO seems to eliminate the starvation problems associated with fuel sloshing around in a carburator fuel bowl while offering both the carefree drivability of EFI and the enhanced RPMs associated with carbed motors. Win-win???

Onward through the fog!

YD,E/PNB

For the next car I'm comtemplating, and doing so quite a bit, I am thinking about a de-stroked motor. My 342 is netural balanced with solid roller cam, lots of lift, and Jesel valve train with some henious springs. Good for RPM.

But, I am thinking of maybe a little 289, max bore possible, some killer heads, all solid stuff like my current engine, and making a high winding piece for even more RPM. Why not give tha some thought? Less torque, easier on drivetrain, lots of fun and noise, and plenty of power? Plus, fits well with short geared transaxles.

R

That sounds like a good plan, too--the fun would really lie in the upper half of the RPM range. Too much torque=too much tire smoke, in my experience. It will be a balancing act between CID and RPM, that's for sure, but one thing that isn't negotiable for me is that high rev limit--I bet the shorter stroke of the 289 crank will help with that issue.

What a symphony I bet the 180* bundle of snakes exhaust makes at high RPM with our beloved SBF!

Suddenly 3 years seems like such a long time /ubbthreads/images/graemlins/frown.gif.

YD,E/PNB

Hi Ron, Doug /all -

Having experienced both 302 and 347 variants of engine in Roy Smart's GTD40 I can say the following.

The original steel 302 he had with 4-bolt mains and heavily modified TFS heads would rev cleanly to some 8000rpm. We regularly saw 7500+ rpm with the limit usually set to about 7800rpm, Roy once recording 7990rpm in second gear (and they call me 'Hooligan!'). Anyway, the motor was ok and certainly had some power, pulling 130 on the quarter BUT, it mainly pulled from about 6000rpm onwards, where it seemed 'all hell would break loose'. For sprints and hillclimbs, it was reasonably successful but did not pull very well out of slow / tight corners and on a twisty hill, you had a job to use any of the power available at higher rpm as it came in too suddenly. It also had a tendancy to destroy rocker gear/pushrods too often, possibly due to excessive valve spring loads.

This all changed when Roy took delivery of an Alloy Fontana 302 block. This was bored +.125" and stroked 0.25" giving about a 343. This also gave masses of low down torque, which made the car pull much much harder lower down in the rev range. This in turn also made it far more effective on both hills and circuits, it pulled out of tight turns more easily than the 302 and on slicks we could hold 4th through Lavant at Goodwood, shifting to 5th on exiting on the main straight.

Personally, I would say the 347 was easier to drive than the 302 as it did not have to be 'wrung' to achieve reasonable times but it did however, not rev as easily as the 302 which was a bit of a pain. At hill-climbs/sprints, where I would pull 7500rpm on the 302, the 343 would'nt rev much past 6200rpm, so I either had to change up, then often immediately back down, or sit at about 6200rpm, knowing that the 302 would have been faster at the same point on track... very frustrating.

In fact I did come to the conclusion that the injectors were too small being fired sequentially, but by the time I had sourced replacements, we had other issues regarding the cooling of the motor that led to its demise last season. /ubbthreads/images/graemlins/frown.gif

Anyway, the older 302 lump is back in the car now and all we need to do is re-map it when we get a chance.

Oops - sorry Doug, I think I have strayed a bit off topic /ubbthreads/images/graemlins/blush.gif but supercharged or turbocharged is way cool IMHO. /ubbthreads/images/graemlins/beerchug.gif

Flatchat and Ron you are both spot on.. But don't the flares and the fat tires look cool? /ubbthreads/images/graemlins/1poke.gif

[ QUOTE ]
BTW--if anybody is interested in that Edelbrock manifold based EFI system, it's marketed by Quality Roadsters (and maybe others)--check this link: http://www.mass-floefi.com/. They weld injector bungs onto a Victor Jr or Torquer single plane manifold and use a 1000 cfm dry flow throttle body with a GM MAF sensor, and if you are building a system that already has Ford ECI there is an adaptor to convert the GM MAF signal to a format the Ford system can understand. Otherwise, they also sell it with a stand alone EFI system for a few more $$. It looks like a simple system and IMHO seems to eliminate the starvation problems associated with fuel sloshing around in a carburator fuel bowl while offering both the carefree drivability of EFI and the enhanced RPMs associated with carbed motors. Win-win???

Onward through the fog!

YD,E/PNB

[/ QUOTE ]

Hershal Byrd has one of these EFI systems on his Cobra and he likes it. I'm not one for the aesthetics of them though - they are busy with a lot of harness and senors.

RE: the carb - if you've got fuel starvation problems you need to look at your fuel system and mount a surge tank if needed. This is a non-issue on a properly setup system and we race with carbs every time we go to the track, no problems. A properly setup Demon, Holley, etc. will offer years of trouble free operation and have a big advantage over more expensive EFI systems - simplicty.

Pete, I hear you on the tires, they look good on your car and a must for Gulf flared cars. But I still think I'll get around the track faster'n you with standard wheels/tires - wait, scratch that, I got no GT40 /ubbthreads/images/graemlins/confused.gif

R