Dietbudda

Ok so i got my bridgeport up and running and need a little help.

First, where should the timing be set at? It's about 20 degrees advanced, but i don't know if this is right

What should i do about an exhaust? Best bets and sound]

Finally, what do the power curves look like for a Bridge with a weber 48 IDA?

Thanks for the help.

12abridgeport

It probably would be better if you retard the timing a little bit just to break it in so it don't get as hot.

As far as exhaust, don't even try to rev the motor hard if you have a really crappy one. If it's not hi-flo enough it's just going to surge on you. That happened to me and i had at the time a really small bridge.

The power curve depends a lot on the sizes of your bridges. Could be anywhere from 4.5-6.5k all the way to 9.6-9.8k.

rotarygod

iTrader: (1)

The power curve is affected by more than just bridge size. It is affected by your exhaust, by how your intake manifold is designed, etc. The port size is only half of it. Don't even remotely begin to think about using a true dual exhaust. Use a collected system and get the collector near the back of the car somewhere. For proper lengths it will take some dyno tuning since everything from your port size to temperature to altitude where you live will play a part in its tuning.

12abridgeport

I'm thinking of getting a g-tech to monitor changes in hp rather than taking the car to the dyno all the time. Has anyone tried it by any chance?

alien_rx7

A friend of mine has a g-tech. Sweet little device. It seemed to give a good estimate but the results were easily thrown off if it was off level when you stuck it to the windshield.

rotarygod

iTrader: (1)

I have one and my best friend has one. We ran them both hooked up at the same time in his Camaro. That car has 2 outlets. One registered a 12.02 at 116 while the other one said 12.04 at 115. Close enough for me. His actual times at the trck are right with that. If anyone tells you they aren't very accurate, call them a pure math genious and then see if they even know how to use it. Then ask them to define the word: accelerometer. It is a good little device. I do have my doubts about the horsepower aspect of it though as it can't calculate wind resistence, gearing, etc. It needs to know the exact weight of the car at that moment. How much gas do you have, how much do you weigh, do youreally know the actual weigtht of the car? You get the idea. Level ground is a must but if you can find it and want a good quarter mile time estimate then it is a great little product. It is absolutely not a substitute for a dyno. It can't tell you if you only gained in one area at the expense of another or if you just gained at all. How you drive will throw off the numbers. Thank god here in Houston there is a shop that only charges $60 for 2 runs instead of some of the more outrageous places.

12abridgeport

That's a good point you brought up about exact weight of the car and wind resistance etc...

So if i drive the car right before tuning it and right after tuning it on the same day and road do you think i should be able to notice some difference then?

DriveFast7

iTrader: (1)

Powerband is primarily determined by port size, location, and shape. Secondary influences are carburetor choke size, exhaust size and collection point. I think that's what he meant.

My full J-Bridgeport's powerband is 7000-9600rpms. Although it is making good power starting at 6k.

A full sized peripheral powerband is roughly 8k-9.6k for comparison.

20 degrees L 10 degrees T total advance is a nice conservative timing that won't get you into trouble. I set mine to 18L during break in just in case but you'll be fine @ 20. Bump it up to 24-26 for some more power and get closer to the danger zone.

Bridge exhausts ...... less restriction is more power of course. I got the ISC racing stainless header, RB dual presilencers and merge into a 3" inlet supertrapp 5" discs. With five discs on there i drive it up and down the neighborhood and the girlfriend said it was loud enough to call the cops!!!!! A 2.5" inlet 2.5" offset outlet 18" can MAGNAFLOW muffler would be nice and certainly quieter but not as obnoxious. I had a similar one on my 12a streetport and it was bearable but tough to talk @ 80mph freeway speed. Still revved real good.

I prefer dyno time, it's real hp and air/fuel numbers and not the guestimate hp of a G-Tech, AND in a controlled enviornment.

DriveFast7

iTrader: (1)