if all the supporting mods are in place and a proper tune is also in store.. can you get some life out of a healthy set of twins ported and modded for non seq at 16psi? i dont expect years but a solid years life would be very good at a daily driving experiance..

when i mean DD im meaning maybe 150 miles a week during nice weather.. once winter/rain comes shes parked in a garage.

 

You have to keep in mind that you aren't going to be driving with 16 PSI for the 150 miles. It's not going to be a problem if everything else can handle it.

 

excellent point man.. ill go ahead and get it tuned for 16psi and keep my fingers crossed!

 

heck i may say go up to 17psi and forget about it. cause Mahjik your right, my car will never see the full boost 24-7 only for a split second and only a few times a week if that.. when i daily drive it I wont be beating the crap out of it. and out of those 150 miles I might hit full boost maybe 2-3 times for a quick second..

will i need to upgrade to a 3 bar map sensor tho for 17psi? and will 93 octane be alright for that with all the other mods performed and a 3 core greddy front mount?

 

You won't need to upgrade to a 3-bar sensor for 17 PSI. As for the 93 octane, there will be a lot of debate on that one. Most people these days will tell you to run some sort of alcohol/water injection. Just use your best judgment.

IMO, talk to whoever is going to tune your car. Tell him (or her) what your goals are and they will make suggestions on what you should do to get there.

 

as has been discussed before, there are so many variables involved with boost pressure, I just pulled my SMB cat off, put an RX-7 Store resonated mp on and went from about 14 psi to 15.5 psi...am I worried? no, because the turbos aren't working any harder to produce 15.5 psi, timing is the same (conservative), and charge temps should be about the same...but I'm running BNR Stage 2s, with stockers, charge temps can increase significantly at high boost levels

also, during the hot summer months, of course charge temps will go up, which can increase the risk of detonation/pre-ignitiion, esp if you're running a smaller IC

 

?

a couple of seconds is all it takes if you have pre-ignition/detonation; 16 is definitely rolling the dice with stock turbos on 93 pump, what if you get a tank of low grade gas?

 

Been done before, long ago. Can be done again.

 

I run my non-seq twins on 12-14psi for a couple of thousand miles before they gave out. Run 98 octane in the UK though, so det wasn't an issue with my map.

 

Not sure if you know this (a lot of people do not) but your 98 Octane in the UK is equal to our 93 Octane here in North America. Octane is not calculated the same in Europe and North America. You guys use Ron and we use AKI. RON = Research Octane Number and AKI = Anti-Knock Index.

RON Octane x 0.95 = AKI

 

i think ill be safe at 17psi with 93 octane.. and if i have too ill mix a lil alc/water injection its no big deal to me.. couldnt i just use windshield washer fluid for the mix? cause its a methanol blend already and cheap.

 

Mahjik, about how much power would you be looking at roughly given a pettit street ported motor, full bolt ons including the ignition, and the non seq twins at 17psi? think that will hit 350-360rwhp with a propper tune?

 

the real question is do the little stockers really produce significantly more flow at 15 psi vs. 17, or are they just spinning into oblivion, way past their efficiency range?

consensus seems to be the latter

 

so 15psi will produce the same power as 17psi?

 

if the turbos are outside their efficiency range (which they are) you're just producing alot more heat with negligible increase in flow

you need to upgrade to BNRs if you want to retain the stock set-up

 

i am planning to upgrade to BNR's later but for now I just want to save money for that and max out my twins.. if they pop a year from now I really dont care cuase Ill be able to upgrade then.

 

With a good tune, 365'ish rwhp is definitely doable. There are people who have generated more power with similar setups, but targeting around 365 or so would be a nice setup.

 

thats about what I want mahjik.. i feel this much power out of the twins will rule.. and the spool up even non seq setup would be insancely fast! before 3200rpm since im street ported also..

 

I pretty much have full boost by 3200 with the BNR Stage 2s (non sequential), hogged out manifold, and full exhuast

don't miss the sequential set-up one little bit

 

Just FYI, it still won't spool as fast as sequential. A few years back, a buddy of mine did:

BNR's Stage 3 (old style) non-seq
Full fuel system
All bolt-ons (ignition, midpipe, etc)
Pineapple Large Street port
Steve Kan tuned 370rwhp at 17 PSI

I was running:
Stock twins in sequential
Stock reman motor
Pettit ECU, stock ignition, stock fuel pump
Bonez DP, Hi-flo cat, Greddy catback
If I was lucky, I was probably around 320rwhp

We did a few street pulls back then. At the start, I would always pull ahead. However, with the power difference he would soon go flying by. Non-seq will never spool as quick as sequential. The people that tell you it does, are kidding themselves. I'm not saying it's bad, but you just need to be realistic about your goals.

 

Making 373 on stockers non-seq @ 16 psi and love it. I have low boost at 13 psi and high boost at 16psi. Afr's are never higher than 11.2 at high boost. I always mix a few gallons of 100 octane in when I run high boost. 15000 miles on this build. I weekend drive the car and take it on 1 long trip a year. Just be concious of what you are attempting and have a good tune. G

 

that's true, but it's really an insignificant difference (even on the street) when non-sequential is done right with all the mods...2800 vs. 3200 rpm? come on...and you can chuck about 300 solenoids and vacuum hoses right in the garbage can where they belong, much easier to work on

 

ever tried it without (the 100 octane)? straight midpipe?

 

Just for debate and keep in mind I am one of the biggest supporters of Non-Seq on this forum. The response difference is huge between the two, there is no replacing the feel of the sequential setup. However, as years of racing rx7s have shown on this forum, the stock twins in either setup can hold their own compared to singles on the dragstrip when considering E.T and the responsiveness of the twins are hard to match on the street. However, trap speeds and interstate pulls are a whole other story

 

That's a matter of preference. That 400-600 rpm difference could add up to 1-2 seconds per lap difference on the track if you are doing something like Time Trials (depending on the track).

Either way, I'm not stating one is better than the other. Just simple facts. Each people can decide what they prefer on their own.