For some reason my cell phone camera makes the car look red,
http://www.youtube.com/watch?v=YZ6Mo...7&feature=plcp
http://www.youtube.com/watch?v=Utb6w...5&feature=plcp
cant find your thread
For some reason my cell phone camera makes the car look red,
http://www.youtube.com/watch?v=YZ6Mo...7&feature=plcp
http://www.youtube.com/watch?v=Utb6w...5&feature=plcp
cant find your thread
I love the pics of the Blazer and the bedliner paint job. I've always wanted one of those, but they're hard to come by. I don't have the want or need for 4 doors so a Tahoe has never interested me. Glad to see that you found the issue in the diaphragm, but I don't think that my car has ever held residual pressure after being shut-off. I don't pay much attention either because I don't have any starting issues. I'm curious about the taller spring just because elevated pressure replacement springs are usually shorter, but have a much higher rate. As long as you've got a good running vehicle, I wouldn't concern myself with something that trivial. 14psi is excellent pressure for TBI injectors and as long as you have a good and consistent idle quality with the larger injectors at that pressure I'd say you've got no need to mess with anything. I figured that at least the higher pressure gauge was off a little as those gauges aren't going to be very accurate compared to a test gauge usually. The camaro is pretty sweet too I might add and I'd take one of those over a 5th gen any day of the week. It looks like you've got staggered wheels on it, though. Are those original or did you install those ? There were too many setups the last couple years of the 4th gen cars for me to remember all the specifics. I've got a similar set of wheels (17x9.5 front 17x11 rear) sitting in the shed because the chrome is bubbling and peeling badly and I haven't found an affordable DIY method to remove the chrome yet. I took them off of my 3rd gen firebird over a year ago and I'm dying to get them back on there. But now I've gone completely away from the topic though.
Mark, I'll post a few things I've found to be common issues on them in your thread.
I was thinking the same thing about the spring, I wish I would have taken pics now but it was late last night. The longer spring was made of heavier gauge wire and was obviously stiffer. I thought about cutting it down to the length of the other one to make it stiffer like you said. Just like a car spring when you cut a coil off the spring gets stiffer. I left it alone. If I do mod the regulator I will snap a picture of both springs and regulator housings. As far as the fuel bleeding off, when my truck sits for a while which it has been doing a lot of here lately, it has to crank longer to start. The regulator spring keeps fuel pressure in the TB so that it starts quicker. The old one with the groove in it was letting it bleed off. Plus the pump has a check valve it so I know thats good now too.
Yeah, we all got a little of topic but hey...it happens with true gear heads. The front wheels on the Camaro are the stock 17x8.5. After I lowered it the rear wheels looked bad tucked up under the quater panels so I bought the 2 rear 17x11's. They are aftermarket. I love thidgens too, my best friend growing up had a 89 Formula 350 WS6. I almost had the car a couple years ago but the engine was locked up. It was his first car, lots of memories in that car. Wish I would have went ahead and bought it.
So instead of starting a new thread I'm digging this one up because this is an issue I'm faced with at the moment. I have two sets of injectors (61&80pph) and need to decide which to use. Either set I'll need to run at higher than stock pressure and I will be sending the injectors off to be cleaned and flow rated as well as having witch hunter measure latency.Quote:
Originally Posted by EagleMark
My engine setup should hopefully be close to 400 hp and assuming 0.45 BSFC and at 85% DC I'd need to run the 61pph and 80pph injectors at 35 psi and 21 psi respectively to give the engine the required fuel. So larger injectors/lower pressure or smaller injectors/higher pressure? What are the pros and cons of each?
I'm running a vortec EP281 pump so higher fuel pressure is not an issue with respect to fuel supply.
Whatcha guys think?
Bigger injectors at lower pressure! Pro is they work fine at that pressure, Con at higher pressure is they open slow and casue issues, no need for latency on TBI injectors, just a service. :thumbsup:
Sounds good, thanks for your input. You don't think it would be beneficial to have latency checked at the pressure the injectors would be operating at though?Quote:
Originally Posted by EagleMark
The only drawback that I can think of with running so much fuel through only two injectors is the pulsewidth at idle, it may be difficult for the PCM to get it to idle as lean as it should. I have found that the smallest pulsewidth I can run is around 0.488msec, which barely gets it down to stoich at a warm idle.
If it doesn't cost any more it wouldn't hurt to check the numbers against what is in the PCM.Quote:
Originally Posted by 907 Chevy
It's be cool to see how they stack up to factory specs too!
But I don't think it's called latency is it? Voltage offset?
In $42 it's "INJ - Injector Correction Multiplier"
In $0D it's "Injector Offset vs. Battery Voltage"
Or did I miss the boat?
No, you got it right. I'd really like to have some solid offset numbers at say 22psi on 80pph injectors. It'd def take the guess work out of adjusting injector offset for increased fuel pressure. Witch hunter charges $25 per injector to measure latency or lag time, whatever you want to call it.Quote:
Originally Posted by EagleMark
You make a good point. Unfortunately, I've been dogged by mechanical issues ever since installing the engine in my truck last summer so haven't had many opportunities to tune anything, including idle.Quote:
Originally Posted by gregs78cam
It seems like running a vacuum referenced FPR would help with resolution at idle? Although it seems like that may create issues elsewhere. I dunno, I'll cross that bridge when I come to it I guess.
What PSI do you run?Quote:
Originally Posted by gregs78cam
There's also an issue that comes in around 20 - 22 PSI and up which slows the injector opening. In $42 the adjsutment is "INJ - Injector Bias " "Added to the total BPW. used to compensate for injectors that open slowly." More pressure makes them open slower.
I'd rather poop shards of glass then try to tune TBI at 35 PSI.
There is no guess, the data is there for voltage and there's no other paremeter? At 22 and 80Lb TBI injectors it's never been changed before? It's not like your putting in an injector with unknown settings where this comes into play.Quote:
Originally Posted by 907 Chevy
A vacuum referenced regulator has it's place. Like if you needed 35 PSI on max size injector but could not get to idle because of what Greg said the pulswidth at idle. These are usually monster motors and works well. But a real PIA when not needed.Quote:
Originally Posted by 907 Chevy
If you have calculated that 22 PSI on 80lb injectors will fuel the engine then you don't need one.
I settled for my BB 80 pound injectors at 15 PSI and I have all kinds of fuel.
As I understand it, injector offset times increase at lower voltages and vice versa, but offset times are also affected by fuel pressure... yes?Quote:
There is no guess, the data is there for voltage and there's no other paremeter? At 22 and 80Lb TBI injectors it's never been changed before? It's not like your putting in an injector with unknown settings where this comes into play.
So if an injector takes say ~700 usec to open at 14V and 12psi fuel pressure...how much longer does that same injector take to open if you increase fuel pressure 50% or 100% or 150%? It seems that this value is very important to have correct as the PCM adds it to injector pulse width, even more so at idle.
Or am I completely over thinking this? Lol
I'm just trying to mitigate Murphy's law for when it comes time to tune this thing...