wptrx7

i am in the market to go single turbo (hoping the band wagon and probably going with the gt35/40), do i have to port the motor? and if i do, WHY?

luigi

Silex

I can't answer that question, but to contribute all I can say is that I have never ported it at all (unless SP pre-ports the motors before reassembling them) and I'm running a t04s.

Bacon

iTrader: (12)

well go big or go home
porting the engine will increase flow wich will make more power and make the turbo spool faster... u can do it without but why spend 3k and not get the fulll potential outa the turbo

wptrx7

bacon i don't understand? "why spend 3000"? does this refer to the porting or the cost of a single turbo kit.

luigi

Silex

I think eh means for the single why spend $3000 and not get your engine ported since it's being messed with anyways .

lzyassmofo

dont port till you blow your engine and need a rebuild. unlike piston driven engines with heads, our ports lie in the center of everything. to get to our ports our whole engines need to be dissassembled and reassembled. this alone is over 20 hours of labor. the ports, for a basic street port are like 4 hours per port. 4 ports total. add up the time add up the cost. you can easily go with a single turbo and have a great time with it on a non ported engine. what makes more of a difference in running high boost is the apex seals and not the port. going to like a 3mm iannetti or hurley seal will provide much more integrity to the engine allowing safer boosting. but you can just go single turbo, enjoy it, wait for your engine to blow, then rebuild with the new seals and port. the only problem is, if you go with a single ball bearing turbo, a lot of times when the engine blows, so will part of the turbo.

lzyassmofo

and most street ports provide around something like 20-30% more power from stock numbers...which is pretty damn good, but considering the cost there are a lot more upgrades that can be done before a port. and on turbo spool...what makes more of a difference then the port is the turbo used, and the A/R numbers.

lzyassmofo

porting and rebuilding typically can cost upwards of 5 grand

Mr rx-7 tt

iTrader: (5)

3 mm apex seals are bad news....DON'T DO IT..

maxcooper

Yeah, wait until you blow the motor and then get a rebuild with a port job. Porting really wakes the car up at the top of the RPM range (it feels great!). But I wouldn't do it until you need to rebuild anyway.

The 2mm vs. 3mm seal debate has been beaten to death, but I chose stock Mazda 2mm for my engine and I'll get the same ones again in my next rebuild.

-Max

KraftDinner

If you are paying that much labour time to have it done, you better watch your mechanic do it. 20 hours just for disassembly and reassembly? Disassembly takes about 20-40 minutes. Reassembly takes about 60 minutes. (this is for rotary specific mechanics). Of course they aren't going to charge you for 1.5 hrs of work, but 20? come on, that's ridiculous. The porting doesn't take 4 hours per port either. For a good rotary mechanic, they can get the ports done (each) in about 40-70 minutes. I can see 4 hours for the disassembly, porting, and reassembly. I know this because I have 1 friend who used to work at one of the most popular rotary shops in North America, and one other friend who still does work at a smaller rotary shop.

jspecracer7

Your joking right?!? I've seen motors bridgported/exhaust ported AND assembled in 4 hours.

HOW THE HELL WOULD IT TAKE 4 HOURS PER PORT?

wptrx7

i think i agree with everyone on waiting till my motor goes to port. it only makes sense especially since i have a strong motor. it was rebuilt before i brought the car (and i had a compression test done before the purchase). now the only thing that scares me is the chance of damaging my turbo if the motor does go. is that highly possible.

luigi

Marcel Burkett

Yes, highly probable it happened to LONDON and many others (I am SURE!!!) , no biggy with a normal sleeve bearing but a damaged turbine wheel on a BB turbo cannot be replaced (cheaply.)

maxcooper

It is possible (maybe even probable) but the odds don't change much if you get the rebuild first. It takes a while to get everything sorted out and tuned correctly when you switch to a single turbo, so I think it is best to get some experience with the setup before you spring for an expensive rebuild. You'll need to re-tune with the new ported motor, but you'll be in a better position to get the car tuned after you work out the other bugs first.

-Max

KraftDinner

I just phoned me rotary friend tonight to make sure those times I gave were accurate, and they are dead on if not a bit high.

JonesersRX7

Doesn't a port job and a single decrease low end hp/speed? I'm not stating... just asking. I thought I read it would be slow as hell off the line with this kind of setup but awesome for track use. But street/strip would suck ****?!?

BTW, what's the difference between a bridgeport, street and all other various port jobs if any?

wptrx7

hey what do you mean "get someexperience with the setup first"?

luigi

Directfreak

iTrader: (2)

SEARCH NEWBIE, SEARCH!

Porting basics

JonesersRX7

Okay... well, I read that and did a search, was up late last nite...So I was not thinking. But for the first part of my question I was unable to find fact or opinion.

KraftDinner

Streetport - this is the first stage of porting, and is what 95% of rx-7 owners have done. the decrease in low end power will be very slightly, not much at all, but you gain a decent amount in the upper 1/2. your driveability will not be compromised at all, fuel consumption will get a bit worse though.

Bridgeport - this is the 3rd stage, since you can have a reg. street port or a large (extended) street port. you will get a lumpy "cammed out v8 like" idle. you will lose low end power, but what you gain in the upper 1/2 will make your jaw drop enough to drive the fat supra in your rear view mirror into. it will guzzle fuel and this is the limit of good streetability. some don't even consider it streetable, but most do.

There are more extreme ports (monster, j, peripherial) which are not streetable at all (i guess )

maxcooper

Cars are complicated, and in my experience it is rare that everything works as you planned it to right after you install it. If you experience a problem with your new setup that causes an engine failure (very common when people go single) you will kill your worn out, needs-a-rebuild-anyway engine rather than your new just-spent-all-my-money-on-a-rebuild motor. Don't expect to bolt the turbo kit on and have everything work perfectly and reliably for 100,000 miles.

-Max