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I got the xcessive lower intake manifold and the ffe primary fuel rail. I have a question about the fuel system. I am looking for 300-400 hp for this build probably right around 350 to the wheels would be perfect. Planned on getting 850 primary injectors. My question is about the secondary fuel set up on the xcessive lim there are four ports for secondary injectors is it beneficial to use all four injector ports at like a 1650 sized injector with ffe four port injector rail meant for the xcessive lim or block off the middle two ports (block off kit included with the manifold) and just run the two injectors like factory at let's say a 1750 or 1800 injectors with ffe two port secondary rail. Sizing wise is that right on or a little overkill is fine with me hopefully would bring injector duty cycle down. One more thing is pump size would a Walbro 255 be good for that would like to keep an intank pump and run with FPR or should I go up on fuel pump size Walbro 450 or do you guys have a recommended pump thanks a lot for any input hope all is well.
I did 2 primary and 2 secondary injectors and I'm aiming for much more power than you are, so I would think the 2x2 setup will be perfectly fine for your setup. I copied what Mad Max did for in-tank fuel setup with a Walbro 450 and modifying the Rx8 pump assembly for return-style. Max is pushing 20+ psi and is having no fuel pressure issues. I'm noticing rock solid fueling as well but I technically haven't had the car running perfect yet and haven't hit any boost.
My car drives fine with 6x 1000 🤷♂️ I know i could use smaller injectors for primarys but works fine imo
I know ID1300 can make good idle
with the adaptronic you can control the distribution some, but ultimately it does make more sense to have the appropriate secondary sizing overall for the best balance. As Dan mentioned, it’s been proven that balancing the injector fuel flow distribution relative to port flow does provide the best power level. It’s not a huge difference though.
With 4000cc total P and only 2000cc S it’s unlikely you can achieve that balance. It doesn’t mean the engine will be way off. With a larger pair of S you might be able to achieve balance by minimizing or shutting down the P1 pair at the iron port position for high load/rpm. That’s a fairly common strategy.
I have 4 injectors in secondary rail and 2 in primary(obviously)
i use 3 stages of injection, they are all independant
im adaptronic you can do injector staging (control when they kick in and blend with other stages) and also the angle of injection on each stages
injector dynamics have good atomisation and i cant say anything bad about my idle
check your emails Team
You are still pushing a lot more fuel into the smaller primary runners.
What happens is you end up with a stratified charge and a less homogeneous mixture in the combustion chamber. You can end up with lean pockets that light off when you don't want it to and super rich bits that don't burn quite as good.
Dont get me wrong. It does work...
but there is a distinct difference in the tune when you balance it better.
I think there is a confusion to primary port/secondary port and primary rail/secondary rail.
With a excessive lower you have 4 injectors in the secondary rail (2 primary port/2 secondary port) + primary rail (2 primary port).
So you have 2x the injector in the primary port, which is counter-intuitive to the size. I would say that the secondary port is about 50% bigger.
In a perfect world with 6 injector bungs, I would think the perfect combination would be somewhere around 725cc/min P1 (primary port, primary rail), 1,000 cc/min P2 (primary port, secondary rail, and 2,600 cc/min in the secondary (secondary rail, secondary port). Then fire them P1, secondary, P2.....With the injectors maxed out, you would be pretty close to equal amount of fuel in each runner for their size.
At 1000, 1000, 1000, you would be putting 2x the fuel in the smaller port, half in the larger. If you calculated out port volume vs fuel being injected its probably 3:1 lopsided toward the primary port....
OF course if your car is running fine then I wouldn't worry about it.
Last edited by strokercharged95gt; 08-17-2020 at 11:38 AM.
Was able to make great progress yesterday got the engine back out and stripped down. Will now get the oil pan drain moved and get the water pump cut where needed and re welded together. Also got a lot of parts ordered yesterday got the rest of the fuel system minus the injectors. Went with the ffe 2 injector secondary rail and the primary rail -6an in and out of primary and -8an and -6an for secondary rail. so I will block the two ports in the xcessive lim and just run two primarys and two secondary injectors. Also got the bhr light weight flywheel (9lbs) with Mazda counter weight for Rew engine. Next is clutch and injectors and getting the engine back together. Thanks for all the input and info guy has been very helpful and interesting discussion. And yes the xcessive has 4 injector spots two for the secondary ports like stock then two that go into the primary ports right before where the primary injectors are on the block so yes you would have more fuel going into the primary ports.
Progress made! Welded up the oil pan and repainted. Also welded water pump housing might be pointing to far down and might have to cut and reweld facing up more but we will see. Got flywheel, counter weight, clutch and pressure plate. Installed all of those today. Went with a factory rew counter weight bhr flywheel and act clutch. Clutch is the sprung 6 puck disc. The clutch kit also came with release bearing and pilot bearing only installed release bearing because engine is new so the pilot bearing is new as well. The engine will be put back in this week or weekend just need to put the manifold on. Once engine is in will test fit water pump modification and adjust as needed. Cleaned up the uim and will be hopefully sending out the xcessive lim and rew uim for black powder coating later this week or next week. Also got the Greddy elbow and will modify that similar to Max's build.
Engine is back in. Water pump is going to have to be rewelded it fits and doesn't hit the steering rack anymore but no way in hell am I going to get a hose on there and I don't want to **** with it but oh well. So point it up more next time haha. Intake manifolds are getting powder coated 1-2 should be done. In the mean time I'm going to mod the pump housing hopefully drop out the gas tank as I'm doing a fuel cell then I can put the trans in drive shaft and ppf fill trans fluid and change dif fluid. Starting to look really good! Thanks.
How much electrical load does the stock alternator handle before mystery problems start cropping up? I’ve chased many issues on boats & dredges with navigation system issues that turned out to be insufficient electrical load capacity.
This car seems to have a large load in its original state.
And there would be the fellow I learned about the electrical load from.
Ya.... there is some controversy about what I think.... but I think.it can be managed as long as you stay with a larger battery and don't run to many auxiliary pumps.
Going to a small battery definitely caused me issues that couldn't be pushed into anything else.
Haha thanks mate. Yeah it's a tight fit but not too bad just enough clearance you can almost just just drop it in. Getting the nuts on the studs is the hard part
The key on an RX8 there is dropping and raising the subframe with engine/trans on it. Working on that for my next NA engine install rather than going through the top. It’d definitely make the low-mount option easier to deal with imo. A little dicy with the chassis on engine stands rather than using a car lift, but am thinking it’s going to work.
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That's how I've been putting the engine in didn't drop the entire front sub frame but just the cross member then bolted up the mounts the took the engine off the stand set it on a plate I built for the jack then just jack it up into place and bolt up the sub frame. First time I tried to drop it down from the top and it sits way to low and is definitely a challenge. Going up from under the car is way easier and definitely the way to go
With the manifold and turbo on it? I didn’t think about it that way, I suppose depending on the packaging and overall size it might make it up through the subframe opening with the engine slid as far over to the other side as possible. I should be able to get the NA motor up in like that no problem though. I still need a hoist to get it up out of the pelican shipping case onto the floor lift.
Edit: now that I think about it, I have to drop the subframe to have enough clearance to get it through the front. It’s dropping the subframe that accomplishes that. So thinking that has to come out.
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Just the manifold on. The turbo would not clear the subframe. Yes just moved the engine over to the left (drivers side) as far as possible then once the manifold cleared the subframe moved it back into place and bolted it up. I was able to get the car high enough to clear the subframe but I just it also depends on what you have on the engine if yours has the intake manifold or the water pump housing on (REW specifically I think the reny one would fit as its lower) it's probably not going to fit as it was close with mine a few inches and it's was basically a short block.
08-13-2020, 09:29 AM
