Highrevnrx7

I have stock ports, and i am going to be running a t78. I want to know how much boost is safe with 1300 injectors, and a fuel pump and stand alone of course. But how much boost can a stock motor hold?

Chris

Resource

You could answer you just as easy as you could hit the search button

Dougie_fresh_007

yup whigger rigger... ur right... but also how much boost is a question of a couple things... are ur temps gonna get too high and are u gonna detonate.. which is more likely to happen that u wont have enough fuel in my oppinion.... but many people will say no... u need more fuel... id say 15 psi is the safe number.... but with everything be cautios..... the best way is to get an a/f monitor and do 3rd gear pulls and change ur boost until u are at an a/f that seems good to you...

racedriver

I had one, 12 psi is max. I would either get 850 primaries, or 1600 secs.

Dougie_fresh_007

wait do u still have a stock ic... if u do keep that boost down

Resource

I plan on running 24psi with my 1300cc/950cc setup.

SERIES7

kaboom! LOL!!! I run 15lbs. daily on my stock secondary 850's.

SPOautos

With a T78 and stock fuel pressure your going to be pushing it with 550/1300's at 15psi which from what I've seen is well over 400rwhp when properly tuned

STEPHEN

jeff48

What is going on here????

cc injector size=boost??????

Since when is that a direct correlation?

You could run 20000s in the primary and secondary with an aircraft fuel pump and still blow your engine with overboost.


Highrevnrx7 we are gonna need a few more parameters to work with before you get a coherant answer.

BTW look at my mods list (including 550/1300s). I can and have run 16psi with my AFRs in the high 11s low 12s and injector duty still under 80%.

Resource

Lets just say that the stock motor can handle much more boost than you are ever going to run.

jeff48

And the choir sings: AMEN

Highrevnrx7

Im going to be running t78, fmic, pfc, fuel pump, 1300cc, full exhausts, and ignition, and whatever else i need to run it. I was wondering how much boost i could run with race gas on a stock motor. Thanks for the help.

Chris

Highrevnrx7

Ill probably run 12psi or so everyday, and 15psi every now and then..

ErnieT

iTrader: (2)

On stock ports, I ran as high as 28psi on 550 primaries and 1600cc secodaries. On the street I ran 15psi with no problems. I would upgrade your secondaries if you want to run more than 15psi. But if you really want to know strap it on a dyno with a wideband and up the boost till your fuel pressure starts to drop and that will be your max point.

Dougie_fresh_007

u ran 28 psi earnie??? did u have any internal upgrades at all???

ErnieT

iTrader: (2)

Bone stock reman. Although it wasn't ran at that boost level long. At the track I ran 20psi all the time with no problems. I also had a bone stock ignition system.

AJatx

iTrader: (1)

You never mentioned what fuel pressure you plan to run.

As for the stock intercooler, just make sure you monitor your air temperature.

Wideband O2 sensor is highly recommended for tuning it on the road or dyno. It'll help with the WOT tuning.

You can run high boost on pump gas given the right tuning and set-up (water injection or what not).
15psi is a safe boost level for most 93 octance fuels.

28psi? You must be running race gas or water injection.

Later on, you may want to get an oil temperature gauge.

J

3isacharm

is it just me or does that seem like a waste of a t78?

T88NosRx7

iTrader: (1)

yeah, 12psi on a t78, you should just stick with stock turbos.

Highrevnrx7

Well, why do you think that i posted this thread. I wanted to find out what i can run on a stock motor so i could figure out what fuel, and psi i should run so i dont waste a good turbo you know what im saying. Can i run 15psi daily? What could i run at the track w/ race gas and w/o race gas? Im new to this allright, so dont give me to hard of a time, you were new to it once too!!!
I appreciate you guys helping me with this!!!

Chris

3isacharm

i'm not trying to insult you, just that a t78 is capable of producing well over 15 psi and you can make similar power and boost, faster (much less lag), and cheaper many other ways. sure it's cool to look in your engine bay and see a big honking t78 sittin there, but it isn't going to make a damn bit of difference if you're only going to run it at 15 lbs on its highest setting.

Highrevnrx7

What would be a good turbo to use. I will probably run 20psi at the track. What do you think?
THanks

ErnieT

iTrader: (2)

Chris,
Don't listen to this BS. Run 15psi daily on 93pump and your fine, no matter if your running the KKK stage 2 or HKS T51R. Anything more than 15psi, use C-16 race gas to be safe. Thats it, no rocket science involved. Get any turbo you want. Just remember the more power you want, the bigger turbo you'll need, hense a little more lag. The lag issue is blown out too. I've driven a RX7 with the T51R and its not bad at all. In fact, when I do it again, thats the turbo Im getting. Its bad ***.

3isacharm

i was just trying to save him some money, that's all. i saw 12 psi daily and 15 psi every once in a while (assuming this was as high as he wanted to go). it just seems like misplaced money.

you're right about lag, once it gets moving there's no issue, and if you're dropping from 5th on the highway, it'll be no contest. choose whatever you want, in the end it's your car and your decision.

maxcooper

Here's some help with the fuel question:
http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

-Max