Bridgeported

A mild port is a small streetport, and an extended port is a large streetport. I'm sure you know this, but a streetport is just an enlarged stock port.
Almost everyone running a large single turbo has a streetport, generally an extended (large one). It's rare to see a large single on a stock port engine, and in north america it's pretty rare to see it on a bridgeported engine (unfortunately).

Hey phatdex, everyone should do crazy and bridge it

Marshall

I just threw together a little Excel plot on Ihor's GT 3540 and LETHAL RX-7's T-78. I used tire height, rear gear, and our 4th gear tranny ratio to determine the rpm for the T-78 since it was in mph.

https://www.rx7club.com/forum/showth...hreadid=144021

https://www.rx7club.com/forum/showth...hreadid=142247

They are virtually on top of each other from 3000 rpm up. With the GT 35/40 being *more* peaky than the T-78. I know that the conditions were different, ect ect, but I wanted to get an idea as to how much quicker the 3540 would make power than the T-78 on the average street ported motor. The 3540 may indeed spool quicker, but it doesn't look like makes any more power than the T-78 in the 3000-5000 rpm range -maybe because of flow?

I'll try to attach the spreadsheet. I guess time will tell once we see some more dynos.

Chronos

this is crazy...The slower spooling T-78 makes more power quicker than the Ball Bearing GT35/40! What gives?!

RICE RACING

I would suggest that they are two differnt styles of engine, one makes power much earlier than the other, so it is hard to compare them back to back.

I know with my engine when I ported it more heavily it did not make the same POWER lower in the rev range even though the turbo spec had not changed.

There are other factors to look at such as the effect of other systems, it is not just a turbo and bare block that make the power, you have manifolds, exhaust, air filters, IC's, health of the engine the list goes on and on and they can all have a large effect on the result Or maybe the conversion is wrong ? as the peak power rpm seems low for a t78 street ported car ?

Chronos

I also thought that it probably had a lot to do with different settings and properties of the two cars...It'd Be a lot better to see a comparison of dyno graphs from someone who switched from T78 to GT35/40 with the same mods and engine.

the_glass_man

iTrader: (2)

Damn this poll.