I'm wondering how much does the stock turbo can hold and the fuel system before a upgrade

 

Depends ... how good are you at replacing engines?

Seriously, you could run 13-14psi on the stock injectors and stock fuel pump, but your duty cycles will probably be topped out. It's not very safe to do that ... so I would conservatively say that 12psi should be the max.

 

How about stock turbos, but upgraded fuel pump, injectors and ECU (such as the PFC)?
How much can the stock twins take?

 

the stock intercooler is a limiting factor at 12psi, IMO.

 

well ima be one to say this, i run 18 psi wit my stock engine and a apexi rx6 turbo, i have my mods listed so all i would say is for drag its prob ok but id go 15 psi of the stockers, im not the smartest cookie and i push my stuff WAY to hard

 

I second that...I was running 12-13psi seq with stock fuel, stock IC and making 301rwhp, 12:1 A/F. Needless to say I didn't run that often at all, very powerful but I wasn't convincened it was safe enough.

I will be try to tune non-seq, with clean/balance stock injectors and upgraded SMIC (and a few other goodies) for 14psi and a/f 11.7:1 and see how much power I can make.

After pulling the plugs, looked like I was a little lean.

I'd like to hear people's opinions on that if you don't mind.

 

Technically, the stock twins can withstand up to 20psi. They'll probably cook the carbon seals and smoke oil after a week or so of repeated abuse like that. There's a point of diminished returns as well ... you're far beyond the efficiency limits of the compressor wheels at > 16psi. With the upgraded pump, stock injectors, and a PFC, you could run 14psi pretty reliably with good tuning. On second thought, you'd need to run hotter plugs too ... so at least 9's on both leading and trailing. Running any more boost would likely necessitate 1200cc secondaries (at the very least ... maybe 850cc primaries too).

 

Well this is what I'm planning on BNR stage 3 kit with a Greddy type 24 FMIC. i was wondering if I could run this set up at 15 psi (IC limit is 15 psi) with the stock fuel system and ECU? I was reading a turbo magazine and there is a black FD. Stock everything but the IC, Intake, exhaust and Peter Ferrel ECU. and he's making 420 @ the wheels.

 

I don't know about that, sounds far fetched to me...only because I have stock everything except Intake, exhaust, pullies, and well look at my sig, and PFS ECU and I'm making 120rwhp less than that guy???

 

I wouldn't push your luck, stay at about 12-13psi.

 

15 psi on the stock ecu and a rebuild will be in your future shortly.

 

no way he's making that much HP to the wheels. With better ecu's available nowaday with price being not much more than the PFS PMC, I'd choose a better ecu if your going to try to make serious HP and want tunability.

Tim

 

I just want to run at 15-17 psi but what I'm actually asking was what kind of ECU and fuel system will work with this mods? BNR stage 3, Greddy Type 24 FMIC, then the rest of the works exhaust, intake, etc.

 

id go power fc, upgraded fuel pump of some sort, 1300cc secondaries and 850 cc priamreis, and a fpr that should do the trick

 

Upgrade fuel...upgrade fuel.....upgrade fuel..!

Its cheaper to upgrade your injectors and a fuel pump vs a rebuild engine bud! Good Luck!

 

386.6 rwhp....

from the old thread with stock twins...but he had an upgraded fuel system....

https://www.rx7club.com/forum/showth...hreadid=152260

 

I could run 15-17psi if I was bold but I stick with 1kg/cm2 or about 14.2 psi sometimes inches to 1.05. I may experiment later if I feel the need for the BNR 3's and I have some more cash.

I have rebuilt stock turbos (the old ones had 100k+ miles so I don't think they went from my boosting), 1300cc sec, FPR, PowerFC w/datalogit.

My duty cycles never or rarely go past 80%. I see 80s only when I'm way up in rpm and boost together.

 

If you run more than 12 psi you should upgrade the fuel pump and injectors (I have 1200 secondaries and a walboro). That upgrade is cheap and will allow you to run higher boost RELIABLY. Almost everyone will tell you your'e playing the waiting game with your engine with higher than 12 without the fuel upgrade. If you upgrade the fuel you really need a ECU to go with it. Look at some of the old hats set-ups (Gordon, Riki, etc) to get a good idea of what will and will not work for a reliable upgrade plan.

 

I forgot Fuel Pump..

 

coudl you run 13-14psi on stock motor, stock fuel system and stock twins with a PFC, FMIC and all the other goodies reliabley with good tuning

 

Did you not just read the previous several posts? Or any of the other hundreds of posts regarding this topic? The answer is NO.

 

Ok let me start by saying the Apex Power FC will work but the stock 2 bar map sensor will only be able to read boost pressures up to 17 psi. As far as the intercooler you can run more than 15 psi. The intercooler's max efficiency is up to 15 psi but you could run a few more pounds without ill effects. The turbos should be run Non seq for 17 psi or your likely to bend a shaft on the secondary turbo with the abrupt spool up with a seq system. The fuel system will need to be upgraded. 1300cc inj will probably be maxed out but can probably be run for short bursts down the 1/4 mile strip. 1300cc inj should be a minimum with 1600cc and custom rail recommended. Use a Stock Supra Twin Turbo Fuel pump. It will support the boost you want to run and will be a direct replacement for your in take RX7 stock pump and is reliable/can be purchased anywhere. The car will be maxed out on pump gas at 16-17 psi. Unless you do water injection etc. You will want to open up the exhaust to flow the extra exhaust and increase your cooling capacity with a koyo or fluidyne Radiator. With those boost pressures you will need to fight the increased heat created. I would also suggest Synthetic oil like Mobil 1 etc. Stock clutch wont last long with that power either.

 

umm....no.

I think it was Max Cooper (may have been someone else) recorded a nearly 100 F degree difference in intake air temps at the track going from the stock IC to the M2 medium. Actually, I think Peter Farrell also noted that (with his IC of course). I think even Mazda would admit that the stock IC is barely adequate for stock 10 psi boost levels.

 

...garbage

http://www.sportcompactcarweb.com/pr...11scc_projrx7/

This was at 12 psi, at 15, you're looking at around 230+ degree F after IC temps. This is an engine killer!

 

------------------------------------------------------------------------
The intercooler's max efficiency is up to 15 psi but you could run a few more pounds without ill effects.
------------------------------------------------------------------------


...garbage

http://www.sportcompactcarweb.com/p...911scc_projrx7/

This was at 12 psi, at 15, you're looking at around 230+ degree F after IC temps. This is an engine killer!





Read the entire post. He is using a greddy FMIC 24 row.