The old engine (and turbo) was getting tired (still need to get it apart) . Decided to build a stronger one and see what other improvements i could make relatively cheaply while i was doing it . Wanted a reliable 350whp on a greddy . Something not done before even with much larger turbos. Also wanted to try my port runner mod idea out .

it looks like with the boost leak fixed you gained faster spool time,
I would think going with a larger compressor housing does create some lag time, but minimal, and your engine maybe breathing in more air so its harder for the compressor to build up pressure to a hungry engine :)

I don't claim to know anything, and I don't claim my statments as facts.

More air in equals more exhaust out for the turbo to spin :P

thewird

Brettus--you lock your ssv open yet?:)

Tried that - like the way it works stock :)

The greddy manifold is the weak point in your set-up ... its waaaay restrictive

Veee shall zeee !

If I can make 350 whp at 10-11psi ................... maybe it isnt ?

^----- Thats my goal~!

I guess that is a difference between a SC system and a turbo? My car responded very well to locking the the ssv open. I also like that I was able to eliminate a fail point. Remember? I lost an engine once when the ssv lost vacuum while I was tracking--it closed and I had a boost spike.
I will send you a data log--see what you think?
My tuner is ok with it.

A turbo wouldn't spike the boost if the SSV failed . :)

Better be quick ! ;)

Ugh still not even close Brett. I should have my engine mount done in the next few weeks though.

dang you and your fancy fail safe systems:)
maybe I need a wastegate too--lol

Speaking of which ..... I really want to rig up something that cuts boost pressure if fuel pressure gets low . Pretty sure i can do something simple with the blow off valve

How about AEM wideband failsafe that can be programmed to cut boost if AFR goes lean under boost.

thewird

that would be interesting. Didnt mazdamaniac have something like that?

Details ?

seems you could get a gauge with a warning light or warning output, then have that go to either your boost controller to cut it, or go to a solenoid connected to a vacuum box that opens when the warning happens, IE forcing your wastegate or blowoff valve to open

But where do you set the warning light ? Given 14.7 is normal running which is too lean under boost , you would need a signal for boost as well which prevents operation out of boost.

by the time the a/f was registered and signal sent it would be late?

Good point - . The FP guage idea is better for this reason i think .

Hmmm.......

Low Pressure Shut-Off Switch - Speedway Motors, America's Oldest Speed Shop

what he said ^^^

Better, it's adjustable.

Nitrous Express EFI Fuel Pressure Safety Switches 15718 - SummitRacing.com

I think he meant a fuel pressure gauge, mine has a warning light and you could rig this up to relieve boost pressure when the warning light comes on I imagine

I wonder if this is what you would want - something that shuts off the fuel with engine under full boost ...... hmmmmmm .

I dunno, what if it just killed the ignition? Could be scary if it killed the EPS. But I am sure there is a way to do it.

Could just run a pressure switch that disconnects the ESS. It will instantly kill the ignition. :)

I wonder if Dannobre has something like this on his ride.

trying to remember how many years ago I suggested the idea and got booed off the stage, lol

I assume you're no longer using the air pump so you can use that solenoid and rewire it to trigger off of a fuel pressure gauge warning light, Stored vacuum in that canister would then open your BOV. Simple yet effective.

great thinking - had actually thought of using a vfad solenoid but it would work much better if i had the BOV line going through that and then connected the vacuum tank to the dump port . The solenoids on the tank are no good because there are only 2 ports.

The same valve could also be used as an overboost protection with the addition of a pressure switch.

Think I've done as much as i can and this is as good as I can get it - within a few hp.

After reviewing / analysing many logs I have come to the conclusion that the Brettspeed port modification has done ............................ Nothing good .
Low end seems to have suffered a little and top end seems about the same . I'm pretty sure a dyno will confirm this.
Disappointed . Now considering pulling it out and going back to stock port runner.


https://www.rx8club.com/attachment.p...1&d=1359329488

it will likely only cause you a problem down the road if you don't

I told you it wasn't a good idea >_>

theiwrd

least you had the guts to try something you thought may help. Kudos to ya.
pm sent.

If I believed everyone that had said that to me ...................... ;)

Cheers OD . I thought i saw something in my dyno of a few years ago that made me think it would work - guess it was a red herring .


Swapping it out now and leaving everything else the same will tell the full story . At least I made it so i could pull it out without disassembling the engine :)

Sorry to here you're disappointed in everything Brett

hehe :)

Well - not everything ....
*The engine build seems solid
*The gearbox has worked out well .
*Stock fly feels better

*The larger compressor wheel : in hindsight I think I should have left the 57 trim in there . Removing the port mod will give me a better idea though.

Since it didn't work out are you willing to tell the specifics now? I'm really curious.

If I remember correctly the solenoids on that tank actually have 3 ports, one on the back is capped off, depending on how those ports are configured you may be able to make it work. I would have to take one of the solenoids off and apply voltage to it to see which ports open and close at what times.

They have three ports. The third one is in the back covered by a black plastic plug/filter. Pops right off.

That's what I thought, now if both the front and rear ports are inputs(One for the Vac Canister and the other for Manifold vacuum/pressure) and the one that points toward the passenger side is the output(to the BOV/BPV) and the solenoid switches between the two inputs it will work.

:yesnod: Props Brettus. Whether it worked or not, you have tested something for the community. Now we can move on to other mad scientist ideas to overcome the limitations of the renesis :)

I've always wondered if it were possible to "yin and yang" the divider into a bigger port divided diagonally or even horizontally.

Good effort Brett. Interested to see the differance after the swap

the plastic vacuum canister with the solenoids can actually be cut off that uim and relocated.
The one for the vdi is not being used --is it?

Yeah - my bad . Had one in my hand but didn't see the extra port hidden under the cover!

The assembly unbolts from the UIM. If you want to separate it from the oil sump filler/vent then you will need to cut the two apart. Either that or build a custom one.