Hey, just for fun I sync'd up the section of the dyno after the a/f went wierd with the section from before it. If the curve was smooth you'd be just over 400 rwhp.

I also think your spool should be quicker with that turbo, at least I'm hoping so since I just bought a GT35R kit myself.

Here's the image:
https://www.rx7club.com/attachment.p...id=86255&stc=1

My spool with this turbo was 3300 for full boost 15 psi. I also had a 10 pound spring. the higher the spring the faster the boost because you utilize all the exhaust flow and the wastegate doesnt bleed it off and slow the spool with a higher tension spring.
I siggest doing the spring change before you tune the car as it will change the tune a bit.

hey zoom zoom, im speculating, ... but dont forget that a boost controller will control the pressure 'signal' that the wg sees, so what you are describing is only when the wg spring alone is controlling boost...in other words it alwasy see the full pressure signal with no boost controller giving intervention.

for example, my track car i ran the entire season with the avcr off, so the wg saw the full pressure signal all the time, that means it probably bleed off a bit before opening fully to control boost, hindering full spool potential, ... if i turned the avcr on but with the same boost setting that the wg was controlling it at, I probably would have seen better spool since the avcr would not show the wg any pressure signal until the boost level required it to control the boost level.

i have the apexi turbo (soon to be r85 kit) so it spooled so darn fast it didnt matter either way for me...

You've got alot going on here, but I noticed on your site that you were at 88% duty cycle at 381rwhp. With 850/1600s, and a 1:1FPR you should be closer to 70% IME. How do you know you have no igniition break-up? I am not familiar with a Profec B, but I imagine it has a gain setting(like duty cycle on an AVCR) Did you max that? Were is your boost controller reading boost from? Are you sure your BOV is not bleeding off pressure? Is your FPR an Aeromotive(pic), or SX(sig) is it adjustable for gain? Basicly, A profec B S/B rock solid at less than 25psi, they are not good at holding boost beyond that however. So, EBC setting, Leak,WG, BOV. Carl

Yeah that's rich as hell, good thing you've got a plug cleaner because those plugs are going to be fouled. Any ignition upgrade would help a little up top, but it does seem like a lot is going on.
When do you plan on getting it back on the dyno and have it retuned?

the boost controler is tapped right into the compressor housing....

Planning in late january to go back for a retune with the twin power in place. Yeah, it didn't take long for the plugs to get nice and blackened when they were first put in....

Why are you reading boost at the turbo for the boost controller? Don't you want the solenoid to reference the pressure in the UIM? Also, your boost controller will see boost sooner, and more of it, than the engine does. When you say you ran X psi, are you using the EBC reading, or some other device? If it is another device, what is the difference between the EBC settng, and the Boost gauge reading(assuming the second is measured in the UIM)? I know Steve likes to read boost at the compressor, but still(after asking) do not understand why. Also, if your gauge is measuring boost at the compressor, you are actually running less boost at the motor(which is what every one else is probably refrencing), which means your spool is even slower than what you are describing. I would move the pressure refrence to the UIM. How were you measuring AFRs? Is the WB known to be a good one? Where was the sensor located? Like I said before, 88% at 380hp is not right for your injectors. I suspect you are running richer than even the dyno showed, and that in combination with the location of your boost signal to the EBC is the source of some of your problems. Carl

the solenoid for the profec is reading from the compressor (steve recommended to put it there) and the gauge is t-ed into the line that runs from the UIM to the map sensor.

I also don't understand reading it from the turbo, it's what's going into the engine that counts. You also bring up some good points.

Just an observation, but almost every Steve Kan tuning session mentions boost control problems, and every time, Steve has had the owner read boost off the compressor for the EBC solenoid(my ill faited tuning session with him as well). I know of at least five seperate examples of this. FWIW...

Every once in a great while ;)

Those numbers are a little lower than I expected.... I remember back when people were raving about the GT35/40 and how fast it spooled and made power. I was considering scrapping my rx6 to get this kit, but it actually made less power than my rx6

if I remembered correctly, David's boost guage reading is tied to the UIM (those two nipples) where the rest of the senstitive conponents (boost control, map sensor, and fuel pressure) is tied by the factory OEM map pickup location. This could explain why his gauge shows oscillation while the map and boost reference for ECU and boost controller is fine.



For those that have a hard time understanding feedback and control systems, you should look at the manufactures manual under *tech* link and Greddy profec B spec II in Greddy's website.

It is very straight forward on how to install it.

If you want to learn more on how control and feedback systems work, you can also get this book in here.

http://www.amazon.com/exec/obidos/AS...358966-0548066

This is the same author/book I studied when I was in college but is an updated version. Eventhough most of the concept applies to electrical in this book, the principle and concept remains the same in both electrical and mechanical. After you read it, I'm not expecting you to understand the math behind it since most feedback system's are calculated in laplace transform (diff eq) but the literature explains a great detail on what and how feedback system works. you'll grasp higher understanding on overshoot and undershoot charteristics in control systems and how to eliminate it along with filtration for frequency resonances in a feedback system.


hope that helps for those who are curious why things were done in a certain way

Why don't you take a look at other's results? This engine is clearly not fully tuned.

I managed 362 RWHP with 12 PSI (Mustang dyno- see the thread) on a stock port reman and that was not a fully tuned run either (clutch died). This is an easy 400+ RWHP at 14 or 15 PSI.

Gene

>>This could explain why his gauge shows oscillation while the map and boost reference for ECU and boost controller is fine.


hey steve, ... but what about the actual dyno sheet, is also showed oscillation? so it wasnt just the boost gauge being goofy, right?

Hi Gene...do you your dyno sheet with AFR for this by chance?

Thanks,

Dave

Thanks
|
V

Not handy, but I can request it from my tuner. Give me a few days...

Gene

Hmm, Which nipple is the stock MAP location on the 3rd gen?

I am running the 3rd gen UIM and have MAP and boost gauge sensor hooked up to the 2 nipples on the primaries of the lowest part of the UIM.

I was getting oscillations of 3-4 psi on data logs once up to full boost. Dynamic effect?
https://www.rx7club.com/attachment.p...chmentid=71357

right in front of your FPR. you'll see a nipple next to the throttle body.

there maybe a possibliity that the vacuum hose that goes to the boost controller may have a leak (hole) causing it to oscillate. It's hard to say at this point though until I can investigate it with David in January.

dont use one guys #'s to determine if you should get a kit.. if you look at i think is "Wargasm's" site you will see other dyno's of 35R's...

Ive seen T-78 and T-88's not reaching even 304 rwhp on some cars! it would be stupid for me to think that thats a fair comparision of that paticular turbo. if the car is not set-up well or is tuned really rich you will generally get low #'s. Look at dynos with a decent 11-11.4 A/F and see what the #'s are.

vist "wargasms" site or do a search and you will find alot of info on many turbos... (not just a GT35R)

very cool.

What boost controller are you guys using? If its one that lets you control the duty cycle then lower that and see if it helps. Alot of times if the duty cycle it to high you will get oscillation.

Jason,
This is the older style Profec...Which, coincidentally, I bought from you :)

Yes, I suppose you are correct...I can't remember but weren't you (PowerAxel) the guy who used 4 different turbo kits? I remember someone had the rx6, t78, t04s, and the GT3540 who said the 3540 was really good. If so can you shed some input?