|
MSII getting 16x16 tables soon
I think I'm going to wait till August/September then I'll give Jerry my bank details again :)
http://www.msextra.com/viewtopic.php?p=159347#159347 |
I think I will wait until MS3 to do a big upgrade - full sequential injection and COP ignition :)
|
Originally Posted by Lex
(Post 117163)
I think I will wait until MS3 to do a big upgrade - full sequential injection and COP ignition :)
MS3 is definately on the cards tho, Ion sensing is where it's at! |
Sequential Injection doesnt that fail at high RPM due to the valves not being open long enough?
|
Originally Posted by LunaticDriver
(Post 117300)
Sequential Injection doesnt that fail at high RPM due to the valves not being open long enough?
|
Originally Posted by LunaticDriver
(Post 117300)
Sequential Injection doesnt that fail at high RPM due to the valves not being open long enough?
|
Originally Posted by Lex
(Post 117319)
You will still spray in the back of a valve, but you will be doing this at the same time during the cycle of each cylinder.
he benefits of sequential injection are that: * you may get slightly better mileage and lower emissions at low engine speeds, * you can tune each cylinder's fuel amount independently (if you know how). The effect on maximum horsepower is general negligible. However, sequential injection does not necessarily mean you are injecting into an open intake valve all the time. The intake valve is only open less than 30% of the time in a typical 4 stroke engine. Once you are trying to produce more than about 25% of maximum HP your injectors are firing for longer than the intake valves are open. If your maximum HP is correctly calibrated to a safe 80% duty cycle, your injectors are injecting well over 50% of the time on closed valves. With MegaSquirt, fuel is injected on ignition events only, and while these are loosely related to cam events, it is a complex relationship, Try to 'squirt' through an open valve under all conditions is generally a bit hopeless, because: * fuel that is injected when the valve is closed doesn't go anywhere, it just sits near the valve vaporizing until the next time the valve opens (some OEMs deliberately squirt against a closed valve to improve vaporization). So squirting against a closed valve does not generally affect the AFR for that cylinder (though there may be a small effect on the combustion quality, good or bad, depending on the port wall temperatures, etc.) * the valve is generally effectively open (0.050") less 300° of a 720° 4-stroke cycle (and closer to 200 for 'stock' engines). So hitting the open valve requires precise cam related timing, * to inject the full fuel charge at high loads/RPMs through an open valve requires very, very larger injectors, about 2.5 to 4 times larger than is usually recommended, * as the duty cycle for the injectors rises, the injectors come closer and closer to squirting all the time, and injection timing becomes irrelevant. However, for those applications for which sequential injection is desirable to maximize idle stability and smoothness, lower emissions, and make incremental improvements to cruise fuel economy, Bowling and Grippo are working on a 'router board' for MegaSquirt-II which WILL do sequential injection (and can be used to operate COP ignition systems as well). It will likely not be released until mid-2007. this is where direct injection has advantages over port injection, it's 1 squirt at exactly the right time per cylinder :) |
Originally Posted by richyvrlimited
(Post 117321)
at low rpms this is true, but at higher rpms, not necessarily, you just can't inject fast enough to be able to.
|
Originally Posted by Lex
(Post 117325)
of course you can inject at the same time for each cylinder ... I am not saying the valve is open, I did say in the back of the valve.
|
no worries, I'm just about to leave work :) have a good night!
|
COP is already available. Sequential injection is a waste as far as i am concerned. It works at very low RPM's but at mid-high RPM's is essentially same as bank injection. Nothing will be gained.
|
Originally Posted by bcrx7
(Post 117541)
COP is already available. Sequential injection is a waste as far as i am concerned. It works at very low RPM's but at mid-high RPM's is essentially same as bank injection. Nothing will be gained.
You'll probably gain 3-4 mpg on the combined cycle, who wouldn't want that? |
by lower rpms i mean under 6-700 rpm. i guess you spend quite a bit of time there to get your car started. ask the guys that switch the wiring on their link to sequential, no noticable change.
|
Or you could ask the guy that wired up his Tec 3 for sequential and noticed great improvement over banked injection. sbrian maybe?
|
Originally Posted by bcrx7
(Post 117549)
by lower rpms i mean under 6-700 rpm. i guess you spend quite a bit of time there to get your car started. ask the guys that switch the wiring on their link to sequential, no noticable change.
I was hoping to see a smoother, easier to tune idle with the sequential injection. |
It's the better resolution that is needed Lex. And it doesn't help if you don't have an idle valve. I am upgrading to MS-2 in the next couple of weeks and we will see how that goes. Although my idle is as smooth as stock, if not better and i am running 550's.
|
my idle is smooth as stock as well except when it's cold (because of no idle valve) but I have to run it a bit richer or it will pop. What I'd like is an idle closer to stoich that is smooth.
I got my 550s in as well and will be putting them in a couple weeks. Let me know how much better the MS2 is. |
| All times are GMT -4. The time now is 08:33 PM. |
© 2024 MH Sub I, LLC dba Internet Brands