I was wondering if anyone has supercharged a bridgeported motor. Bridgeports can make massive top end power but tend to not come alive til 4k, but if it was supercharged it would have good low end too. Not to mention the fact that it should yield around 400-450 hp from a 13b4port. My main concern would be the blower being able to handle the revs that a Bridge is capable of. Any info is appreciated

 

I would be searching in the direction of a turbo. Considering it uses spent energy and you dont have to worry about revs! If you are worrying about torque, don't. You can get a turbo from a Grand National or a Merkur XR4ti. Both produce more torque than hp and produce it at about 2000rpm. If you cant find a merkur turbocharger get an SVO or thunderbird Turbocoupe. But that's only if you dont wanna spend any cash.

 

Its better to turbo a bridgeport. It is good to turbo or supercharge a stock, mild, or extendport. Superchargers are better for engines with long duration but not too much overlap. Turbo is good for either though.

 

it's not good to turbo or supercharge a bridgeport. Since the exhaust and intake overlap, turbo will force some of the air into exhaust which is useless. It's recommended to go as far as a streetport on a turbo or supercharged rotary

 

The reason I said its best to turbo a bridgeport rather then supercharger is the lag. Supercharger gives much better lowend response, and your right, it forces some out the exhuast raw. However with a turbo bridgeport, the low gas speeds at low rpm keep the turbo from spooling up till a little velocity is going. Then the overlap doesn't matter much as at 4000rpm+ the intake charge will not be able to escape out the exhuast.

I've heard of some TII people going turbo bridged with good results and even more response in the 3000rpm range which is pretty low in the power band on a bridgeport.

 

Well in turbo world, it's a NO-NO to have a bridgeport turbo, you can ask it on Turbo forum and I am pretty sure you will get flamed at.
If I had a chance of having a Bridgeport engine, I would keep it NA.

 

I happen to have a N/A bridgeport, I wouldn't turbo it for the reasoning that carbon seals are not for boost since detonation shatters them quickly(I know) and compression is wrong and cost, etc, etc. I like using 87octane thank you very much.

 

yeah its a big no-no, thats why all the top drag racers use bridgeport/combo port jobs.

i would just look at a turbo setup instead of a supercharger for 2 reasons.
a. power lost from drag of super charger.
b. a properly sized turbo can make the same power at lower rpm as a supercharger

but you can do what you want its your money

 

I think you need to spend more time in said Turbo forum. There's quite a few people on this site running either half or full bridge and peripheral ports with turbos.

If you're after maximum horsepower and aren't too worried about poor fuel economy and reduced driveability below 4000rpm it's the only way to go.

 

Actually it's the exact opposite... claim that you can't turbo a bridge/peripheral engine and you will be flamed mercilessly

plenty of forum members have turbo/bridge setups... soul assassin, crispeed, pluto, Exit13B, MikeL....

heck I'm sure if he weren't so busy, RICE RACING would come in here and give you solid hard numbers on bridg/peripheral port turbo engines

 

Exactly. You can turbo a bridge, but I have personally seen it as it was being ported. Crispeed's bridgeports (for turbo use) are different. They have slightly different position and shape of the ports to minimize overlap/blow-thorugh at higher RPMs.

 

I didn't say you can't turbo a bridge. But face it, say you have 10deg. of overlap between intake and exhaust ports at 5000RPM (just for example) and you are running 15PSI of boost at the same RPM, so the job your turbo is doing is to compress the intake gas and send some of it to exhaust without burning, tell me which part of this is efficient???

 

You forget that there is pressure on the exhaust side too. It takes force to spin the turbine!

 

AGAIN..

 

This is pretty much just crap. Bridge and periheral ports have been shown to provide supperior VE in the order of 20-30% (which means more a lot more torque) when compared to normal side ported engines. This is from revs as low as 2000rpm. Apprarently intake design plays an important part as they need to maintain good air speed to work well. The only problem is low load running where they suffer from high BSFC which means poor fuel economy and driveablity. This is the only reason they aren't for everyone as a street engine but in terms of outright power they're unbeatable.

 

well i guess it would be possible to change the design so there is almost no overlap, but then the HP will be sacrifized.

 

Overlap is WHAT MAKES THE POWER POSSIBLE!

The overlap period is bad on piston engines where the intake and exhaust valves are right next to each other. But in the rotary it's BENEFICIAL because they are at diametrically opposite ends of the chamber. Intake and exhaust resonance tuning allows the incoming inlet charge to force out the exhaust charge, or likewise the outgoing exhaust charge can "draw in" the incoming inlet charge. Much superiod chamber scavenging compared to no overlap! The tuning gets to be to the point where it's similar to a 2-cycle engine in that resonance tuning is key for big power.

Now with a turbo, things aren't much different... the pressures are higher but the resonance tuning is still there. I've said it before... what is so magical about bridge/peripheral ports that they stop working above atmospheric pressure? Do they stop running if you take them down to the Red Sea, for example?