Bridgeport
 

So I'm about to get a turbo II engine and I looked a little in how to do a Bridgeport and street ports on YouTube and what not. It looks really easy if you get a template, but I wanted to know if there's anything else to it besides cutting the metal like if you need to do things to make the new metal that's exposed stronger. And I was also curious as to how much power I'd expect to get. I'm planning on 1050cc injectors, k&n intake, a 3 or 4 inche straight pipe, and a tune. Thank you

Unless it is a big single turbo and you are happy with more exhaust heat and worse fuel consumption all the time and less bottem end pickup and will the getting the rotating assembly clearanced and balanced to rev enough to work the ports don't bother.

If you extend youself learn as much as you can about side and corner seal path/support. The better extend closing edges are basically a straight diagonal line with a really tight corner for the side seal to sweep along rather than letting it sag and slap back onto the plate or worse grab the end of the side seal (if early open and end of side not supported) like poorly done rounded top ports. Again if you go radical on port close timing it just pushes the charge back out at low rpm which means less torque. A bit earlier open and later close should give you more midrange and top end if you have a decent turbo. If the compressor and turbine are poorly matched (too large compressor for the hotside) porting could send you backwards.

What would you consider a too large compressor for the hotside? 70mm mated to a p trim?

It will still make power but should really be a Q trim turbine with that compressor to get the best out of it. That would be better than the T66/35R combos people were trying to do a few years ago.

Ok thank you it sounds like it's not worth the work haha, so with the upgrades besides that, that I have listed, what horsepower could I expect to put out?

Extend port, big exhaust, decent intercooler, minimum GT37/GTW38/ P trim/s362 size turbine with 62mm+ compressor inducer with those injectors and enough pump to support them you are looking at

​​​​​on E85 about 0.77 lambda ~ 11.3 petrol equivalent AFR ~450rwhp Dyno dynamics, 520ish whp on a dynojet (?) at around 23PSI.

On pump fuel with water and or meth injection stepping up to a 64+mm compressor inducer on lambda 0.72ish at 27ishPSI 500whp on DD 575ish on dynojet. More (towards 600 Australian whp) if meth mixed in AI or you are happy to run 11s AFRS with plenty of water. Will need strong ignition.

slighrly larger turbine/compressors will make a bit more torque and extend the peak hp/rpm at any boost level but be laggier.


If you are looking for those numbers you probably want to consider clearance and balance of rotating assembly and better through bolts/studs for peace of mind but I know a guy who was making over 550whp on DD with soft ignition timing (CDI leading but IGN01As would do) on pump and straight water with an ebay chinese knock off gt turbo and self ported (large EP) motor with mazda seals with standard rotors and through bolts.


Also note Australian "98 octane" is like your 93 octane, our 91 is like your 87.

​If you are talking a standard s4/5 turbo it will max out about 250whp on a DD ~285 dwarf american horses 😁 probably need about 0.6-0.7 bar 8-11psi to make that happen.

somewhere between those number for intermediate turbos.

A bridgeport on a standard or highflow factory turbo is a fashion statement only.

Thanks for the advice!