BDC

Wee, I love my rotary.

B

crispeed

As The World Turns!

crispeed

Race Cars!
Just about 99% of the 7.99 and quicker cars are semi-pp now along with a nice big S-400 or GT-45 turbo, an E&J 4bbl throttle body on a 4bbl intake, 10 to 12 injector, some M3 methanol and most important a good engine builder, good tuner and good chassis builder and vola you have the combination. !

Oh yeh! I forgot you don't need an adjustable clutch like the Yankees do! All you need is to run an E-bbost controller to vary power by gear!

HMMM! Let's see? Did I forget anything else?
Ok I'll sum it all up!

The leaders
Falito.......OSO
Edwin......Siguel
Gaby
Maiky
And the list goes on and on.
You guys are just followers!

BDC

Attached is my dyno sheet from March 30, 2000. Linked below is the dyno sheet from Dec 30, 2006. Same turbo (Turbonetics 60-1 HIFI). Street port in 2000 vs. a half-bridgeport in 2006 as well as going from a chilled air-to-water intercooler to a stock top-mounted intercooler. I invite everybody to thoroughly compare the two and critique them.

http://bdc.cyberosity.com/v/Tuning/D...geViewsIndex=1

John,

I haven't done anything special with the BP and I've never claimed that I did. I just experimented with it a few years ago and found that it worked on a turbo app, despite my predilection for street ports. I still don't understand all of the science behind it, but it nonetheless still works. I just make a couple small cuts and let it do its thing. Zoom, zoom.

There were a few logs that went to 7500-8000rpm, but admittedly not alot. They were all on the street and only one on the dyno. The runs on the dyno were my fault. I screwed up in going to the session with overconfidence of the tune, not recognizing the lack of high RPM street tuning I'd done by way of not removing fuel way up top once I was ramping alcohol up. But, I suppose you'll wrench that out of context, make up an excuse about that, project that on to me, then argue against it as you've done I don't know how many times already, right? Give me a break, man.

Horsepower?! What's the big fricken deal about a single horsepower figure? Whatever happened to torque, powerband, peak power, etc. etc.? Are you willingly choosing to ignore the torque figures on my car, not to mention the overall powerband, given the turbo that was used on that setup? Nevermind the fact the bridgeported motor was easily able to out-pace that 60-1 HIFI compressor without breaking a sweat. Nevermind the fact a bridgeport's potential power band, given having enough compressor up front, doesn't drop off at your typical 6000-7000rpm range like you and your buddies' street ports. Nevermind the fact that the boost thresshold is dramatically more aggressive and poised earlier in the powerband. Nah, none of that stuff matters. Don't confuse you with the facts, right? What the heck do you think happens when you crank the VE way up in a motor anyways, John?

Think outside the damn box already.

B

J-Rat

iTrader: (2)

I dunno, my streetport made 395 ftlbs of torque and 60 more HP the you at the same PSI rating..

But I dont really care about the SP/Bp debate.

rotarygod

iTrader: (1)

Are you running a 60-1 HiFi? Try running 15 psi on a stock TII turbo as wee how well it does. Your results are irrelevant compared to his.

enzo250

No Way Man. All the fast guys run street ports man..

Here's an easier way to understand it for those that don't get it..
PP > Semi-pp > BP > Street port

thegoatc

ok so the debate is street port over bridge port right and from a timing stand point the street port is more practical in the turbo application because the exhaust intake overlap is better than on the bridge port there for the boosted air is not just ramed out of the exhaust port instead of being used.

but on the other hand if you are able to build up the boost enough then you are able to over come the lost boost pressure in the overlap by sheer flow. making the bridge port a higher hp engine with suffecent boost.

like stated before the compression ratio is going to make a difference also so a stock engine street ported is going to make more power at lower boost than a bridge port.

just my 2 cents but what do i know this is only theroy.
eric

Turblown

iTrader: (12)

Exactly, you don't want overlap on a turbocharged car. Infact if you could have zero that would be the best, however the car will hardly run out of boost. And you don't need a ton of intake duration under positive pressure. This is quite proven on piston engines, and I'm not speaking from what I heard or read on the internet. I've personally yet to try it on rotary however, I'm going to find out for myself shortly..

classicauto

iTrader: (3)

Well you've just touched on the biggest missing factor in this thread.

Turbo or N/A?

Since most are talking street port on a turbo car, we'll go with that a bit.

Really, I can't see port size/shape (bridge vs. street) making a gigantic difference in power because the air is being crammed into the engine. It won't care if there's a brow to go through or not because its got a giant turbo at the other end mashing it into the engine.

N/A, bridgeport OBVIOUSLY holds an advantage because there's nothign there to jam the air in.....it has to find the engine on its own. Bridgeport = less things in the way and more space to sneak through, therefore making more power.

Me - I have a 1/2 bridge. I love it. But I don't really care about the whole debate, I just love hearing the NOISE!!! brapbrap...brrrapbrapbraaap...brrrapbrapbrap

RacerXtreme7

iTrader: (2)

Your not going to blow boost out the exhaust port in high over lap engine (we are talking about high load open throttle here). Your exhaust manifolds pressure will NOT ever have lower pressure in it then your intake. Theres is an occurance called "crossover" were the intake and exhaust pressures almost or do match, maybe for a couple hundred RPM on a purpose built RACE engine thats peaky as hell you might *might* see more intake pressure then exhaust. But for every day street even high boost race cars, your exhaust manifold will ALWAYS be higher then your intake pressure. We're talking super high end motorsports here to reach "cross over" like Indy of the 80's eras and RACE only engines.

Not makig it up, not saying this is theory, just given scientific facts. I'm not stating my "opinion".

now for my "opinion" as derived from personal experiance.

Every car I've ridding in and dyno I've seen, the half bridged turbo cars spooled faster with more of an off/on flavor over the street ports more progressive/linear boost onset. The Half bridged cars make A LOT more torque from 4000 RPM to redline. Nearly half to full bridge car I've ridding/drove also had horrible light load missing and bucking which makes for shitting cruising. I'd say roughly 3 of 10 were tuned right and didn't display this light load bucking/missfire. I'm sure is a combination of port work, intake and exhaust combinations along with tuning amonst other details.

~Mike...............

13B-RX3

iTrader: (2)

HMMMMM this shall be my new computer desktop.

KNONFS

iTrader: (14)

Damn, don't know if you are with me or at me

Do you know if they are running BP along the semi PP?

13B-RX3

iTrader: (2)

Is their first best kept secret in that post somewhere?

crispeed

Allen,
You're 99% away from 'the' combination. You have the parts and tuner. Now all you need is a motor!
So what's it's going to be?
Like Enzo said.
Sp, BP, Semi PP or PP?

13B-RX3

iTrader: (2)

Hmmmmm tough call. My mind says P Port but my wallet says stock


The one thing that is going to hold me back it the transmission .

J-Rat

iTrader: (2)

My compressor is quite similar to his.

crispeed

As the world turns part two!

enzo250

Not sure if im reading your statement correctly here.
But what i got from it was you said exhaust pressure will never be lower then intake.

Your dead wrong.
You even mentioned F1 from the 80's turbo era.
They had intake pressure almost twice what there exhaust pressure was.

I guess you don't have any experience with high hp /or big turbo'ed engines...

crispeed

That seems to be the general theme in here.
Everyone does have experience quoting others and what they have read elsewhere!

kabooski

I've been using street ports for years now
and I'm about to try my 1st Half-BP and another internal mod
I pieced and built a setup "specificaly" to use for a BP

Your setups needs to be built and planned for what ever engine mod
your going to use....You can not expect a .81 P trim
and a 3" exhuast that you used in a SP then switch to a BP
and expect great gains if any...WRONG combo
You also need a great tuner who has experiance with BP SPP PP
in a turbo application... diffrent tuning animals SP and turbo BPs

crispeed

Exactly!
One mod done in the right direction allready!


Well you allready have that covered.

13B-RX3

iTrader: (2)

Make sure to get some footage of the beast on the dyno, i can't wait!!!.



As for the SP/BP debate i might as well throw my $.02 in. What port you go with should be derived from what you want from the car, not the other way around. For a street to moderate performance a street port would be fine. If your more concerned about going as fast as humanly possible. It is an undisputed fact that a bridge/semi p port/ p port will make more power above XXXX rpm.

When was the last time your tach dropped below 4500 RPM during a 1/4 mile pass?


(the views expressed by this ******* are not based on anything)

joeylyrech

iTrader: (11)

Falito was running a SP before he crashed,now hes coming back with SPP
The Siguel crew its running semmi pp with bridgeported secondaries
Gaby and Mike same as above,in my opinion i use to own a halfbridged turbo fc and a old fb,now i have a sp and its not the same thing,the streetport drive smoother with a linear powerband but at top end my boost start falling and i get that felling that i reached the end of the powerband .the bridgeported fc was more agressive power band was way longer and it kept pulling all the way up 9,10 grand and i never reached that point when you feel that theres no more power(the end of the power band)DAM I MISS MY HBP

crispeed

You bring up some of the best points though.
Seriously you can have a bridgeport with a wider powerband than certain street ports and vice versa!
It's all in the combination and what you want.