Brentis

Ok I got a 94 fd with a bunch of stuff on it, but last time it dyno'd it only got 280whp at RP at 13psi after several efforts to tune it for more. (added new plugs, did 25 runs so it was probably heatesoaked to hell- probably dynos around 300 or so now. Chris suspected it was due to a aging primary turbo. (entire car only had 21k miles on it - but could be). The primary will only boost to 11psi or so. My secondary will hit 13psi though.

Recently i had Don at Marvelspeed install a act s/s extreme clutch and he said he found a busted vacuum line that made a difference when he drove it. Feels better but I can't boost much more than .9 on my pfc regardless of the boost settings on the pfc.

Boost leak is possible, just don't know where it would be. I'm planning on having Don scrub the car for leaks and vacuum line issues to solve, but in lieu of him finding anything - what is the best way to get 335 whp.
not really interested in a midpipe and don't think it is required to get to 335 whp - I'm willing to crank the boost up to 1bar to get there.. BNR stage II's seem like a good alternative if I'm going to have someone take my turbos off - I should probably upgrade - right?



My perf upgrades include:

pfs exhaust
high flow cat
greddy smic w/ spal fan & petit duct
pfc
apexi intake
hard intake pipes
greddy elbow
efini y-pipe

the vacuum line upgrade's been done with tie wraps.
I've also clamped the BOV hoses.

So give me your ideas on what to buy or how to fix!

Thanks!

Foz'sRX-7

How about adding a 3" SS downpipe, you can get one from Pettit Racing for $150. Also, take a look at their cold air induction system.

go to www.pettitracing.com

wanklin

iTrader: (2)

downpipe, grounding wires, and stock turbo upgrades ,w/ a small increase in boost, should do the trick. There are plenty of FDs making around 375-400hp on the stock twins.

7racer

i think Brent has a DP...

Almost sure of it.

Brent why not upgraded turbos and larger secondaries....

not super cheap but the easiest way to get to where you want to be...IMHO

Godzilla-T78

Get rid of the PFS exhaust.. its a power hog.. Get a hks hiper or somthing and free up that flow.. and like said above.. get a nice downpipe. upgrade your injectors posibly, get a fuel pump and FRP. Also a boost controler and get that puppy tuned for about 14lbs.

Godzilla-T78

Here go to www.thepartstrader.com and get you some turbos

jramosrx7

Here's how my car is set up. With a midpipe, it does 337 at the wheels. With the hi-flow cat, ~315. Boost is just a tad over 13, 13.2 psi.

Medium stock-mount intercooler with polished pipes and GReddy intake elbow - M2
Cold-air intake, carbon fiber - M2
SS downpipe - M2
Bonez ss hi-flow cat (for smogging and most street use)
SS midpipe - ?
Cat-back - Racing Beat (RS*R)
A'pexi PowerFC w/Commander
Cosmo fuel pump for stronger fuel delivery
3 mm seals
SR Motorsports radiator
CWC second oil cooler
J&S knock retard sensor with a/f meter
Jacobs sparkplug wires
Rotary Performance "Power Pulley"
RPS Turbo clutch

Running 13 psi means I have room to do more, but am quite satisfied with it as is.

7racer

jramosrx7...

with the 3mm seals did you port the engine?? Brent is still stock and I think that would make a difference.

Brent, regardless of what you end up doing, I think you need to figure out why you can't boost past .9

If I remember right you could before. Fixing that might be the CHEAPEST way to over 300hp

jramosrx7

No porting. The engine was rebuilt by Rick at Rotary Performance in Pleasanton, CA. He cleaned up the ports a bit, but didn't make them bigger. It's my understanding that the stock ports will easily accommodate up to 15-16 psi, and since I have/had no plans to go that high, I left tham as is.

the_glass_man

iTrader: (2)

Fix your turbo problem and then up the boost. With some good tuning you should make it.

Radical Rotary Avantgard

Brentis, bite the bullet and think SINGLE!!!!!

RTS3GEN

I'll chime in on this one, although your primary turbo may be not producing full boost, 13psi off the stockers is still enough to net more than 280 at the wheels. Although I have a ported motor, with essentially the same mods mine made 342rwhp at 14psi. At the time I had a high flow cat but still made a nice amount of power. 335 is attainable with your setup however, if you have a vacuum leak as you suspect, this will affect the output greatly depending on where the leak is. Also, if the clutch was slipping on the dyno obviously you lost hp through that, and lastly if the tranny or differential is damaged, you can eat hp in the driveline if there is excessive resistance. Good luck in your quest.
Art

Brentis

sorry guys - I also have a downpipe and a fuel pump. I always forget a couple of things..

I also got a new clutch after I had it dyno'd their is the possibility that it was slipping a bit on the dyno - hard to tell though. Could imperceptible slipping account for 5-7% of HP loss?

RTS3Gen - I agree that I should have more at 13psi. If the pfc is registering 13psi though isn't the engine getting that much boost? Does it mean other factors are that far off (timing/etc.)?

Thanks again!

Jason

iTrader: (5)

Three things I see holding you back. The catback, highflo cat and intercooler.

If the clutch was slipping on the dyno you would smell that.

Jason

kwikrx7

yeah, you'll probably get some more power just by figuring out your boost problem - but as others have said - a more free-flowing exhaust, a better IC like the M2 med or large (or fmic) and a midpipe will get you to 335 at 14 psi with your mods. Don't know if you need new turbos - the stockers can handle 13-14 psi for a little while - especially if they only have 21K on them. If 335+ rwhp is what you want and you want to keep the HF cat then you might want to go BNR 2s. They are much better than the stock turbos as far as spooling and power - mine made 380 rwhp at 15 psi even with a HF cat. Also get the HKS Ignition amp - I understand that made a huge difference on my old car from what the new woner was telling me.

Louis M

i'd prob. say tuning... go down to gothom and see what they say

Brentis

Thanks everyone - why does the pfs catback suck? Granted - I don't like the way it looks - but what is behind its suckiness?

As far as the hks ignition - I want the cheapest way! That thing is expensive and I have trouble seeing more than a few HP's from it.

I'd like to think it is tuning, but one thing I left off is that I clamped the precontrol hose so that it would never blead boost from the precontrol wastegate. I set the primary pfc to 1 bar and found it impossible to get past .76bar or so. It was pretty hot out, but I'm clueless.

Might be the tuning, but if I recall my afr's were not that bad. It may be my hiflow cat. The thing is now rattling when I start & stop my car. Probably a big molten ball of ceramic in the middle of my exhaust passageway...

The thing that keeps me from going midpipe is a) added noise, b) lost torque, c) no incremental 1/4mile improvement. I asked several "1/4mile experts" on the zo6 board and some ricer board which dyno chart they prefered and they both said the flatter one with the hf cat. The dyno charts I refered them to were these...

http://www.efini.net/myrx7proto.htm

Likewise someone on this board once upon a time posted that the difference in their 1/4 mile runs was same trap and a 1 mile an hour improvement with the midpipe.

I'll probably have my crap bonez cat converted to a resonated midpipe....

thanks for the thoughts.

7racer

Brent,

how long do you think the high-flow lasted you???

You don't drive the car much and it is alittle disconcerting to me to see you needing a replacemnt so soon especially with running the airpump.

Herblenny

iTrader: (13)

hmm... this is just my suggestion.. I drove my car today and I hit 1.06 bar.. kind of unusual for me... anyhow, I think you might have boost leak somewhere.. possibly small maybe one of the nipple or something around the UIM.. My car is still running on stockers and my primary hits .9 easily.. I know my secondary is going.. but still hits .85..

Also, I remember from Rotary revolution earlier this year.. i remember seeing a guy who made 360-370HP with non-seq (true non-seq)... That might be the way to go.. I think he had stock intake and IC with full exhaust.. i'm not sure though... All I remember was I was very surprise to see it.. Do anyone know who this was???