Injector questions
Thread Starter
Intermediate
Joined: Jan 2013
Posts: 47
Likes: 0
From: Leominster MA
Injector questions
Right now I'm running a mildly modified late '86. Edelbrock intake, SLP runners, buncha other stuff. I had planned to pop in a set of Bosch III 22lb injectors, but they leaked like a sieve so I put back the stockers.
Car seems to run fine, but the SLP runners were a tight fit on the #7 and #2 injectors, forcing me to remove the spring clips and cut back the injector plugs a bit to fit (barely). One of them (#7) ticks rather loudly. Seems to work ok (runner temp seems in the ballpark), but I'm reconsidering trying to install Bosch IIIs, this time 24lbs.
I'm assured by another vendor that their IIIs have a modified seat that stops any leaking. I'm looking at the blue 24lb set. I'd like to increase my capacity a bit for some better mid-high rpm capacity and some future headroom.
These are rated at though 43.5psi. My pump is 40psi. If that's linear, then the 24lb/hr rating drops to 22lb/hr.
Questions:
1. Any advice on leakage?
2. Should I go bigger than 24lb@43.5 to get headroom?
3. Recommendations on what injectors to use, and how to reprogram the tables for them? BTW I use modified $6E and run at 13.7 stoich (as low as I dared go with the narrow band o2).
Car seems to run fine, but the SLP runners were a tight fit on the #7 and #2 injectors, forcing me to remove the spring clips and cut back the injector plugs a bit to fit (barely). One of them (#7) ticks rather loudly. Seems to work ok (runner temp seems in the ballpark), but I'm reconsidering trying to install Bosch IIIs, this time 24lbs.
I'm assured by another vendor that their IIIs have a modified seat that stops any leaking. I'm looking at the blue 24lb set. I'd like to increase my capacity a bit for some better mid-high rpm capacity and some future headroom.
These are rated at though 43.5psi. My pump is 40psi. If that's linear, then the 24lb/hr rating drops to 22lb/hr.
Questions:
1. Any advice on leakage?
2. Should I go bigger than 24lb@43.5 to get headroom?
3. Recommendations on what injectors to use, and how to reprogram the tables for them? BTW I use modified $6E and run at 13.7 stoich (as low as I dared go with the narrow band o2).
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
First, many are claiming that Bosch III yellow 280-155-700 flow 22 lbs, but are really closer to 20. I've dealt with numerous people who's BLM counts go way up, and even to the max add fuel of 160. Using an adjustable regulator with pressure up to about 48, and reprogramming the flowrate from 22 down to 20 can bring back most of the drivability. The type III's require a slightly bigger O-Ring just above the bottom one to keep them from dropping into the intake and staying up in the rail.
The Bosch blue 280-155-715 flows just a bit more than 24, but installed at 40 would be a great fit for you. Why in the hell you changed your AFR to 13.7 I'll never understand. I rarely go under 14.5, and the ECM goes open loop under WOT which should be tuned to .860 or slightly higher on the O2. this will get you close to 12.5:1 AFR.
The Bosch blue 280-155-715 flows just a bit more than 24, but installed at 40 would be a great fit for you. Why in the hell you changed your AFR to 13.7 I'll never understand. I rarely go under 14.5, and the ECM goes open loop under WOT which should be tuned to .860 or slightly higher on the O2. this will get you close to 12.5:1 AFR.
Thread Starter
Intermediate
Joined: Jan 2013
Posts: 47
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From: Leominster MA
One of my projects has been to try to get the car to run cool, as in between 166-177 or so (with the AC off). One way I did this was to richen the mixture a bit. That, along with several other things, has me running at those temps even on a hot day. When the hot weather returns, I'll experiment with a higher ratio since I've made further mods since changing the A/F.
One thing I can't cure is the hot-air shroud the condenser makes. I've thought about fabbing brackets to hold a smaller (in LxW terms) condenser that lets some cool air get to the radiator. I could get away with that because my aux fan is triggered by the compressor clutch signal. But unless I get an 85F-plus day in November (not looking likely up here) I'll probably wait until summer to see if I even need it.
One thing I can't cure is the hot-air shroud the condenser makes. I've thought about fabbing brackets to hold a smaller (in LxW terms) condenser that lets some cool air get to the radiator. I could get away with that because my aux fan is triggered by the compressor clutch signal. But unless I get an 85F-plus day in November (not looking likely up here) I'll probably wait until summer to see if I even need it.
Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
One thing I can't cure is the hot-air shroud the condenser makes. I've thought about fabbing brackets to hold a smaller (in LxW terms) condenser that lets some cool air get to the radiator. I could get away with that because my aux fan is triggered by the compressor clutch signal. But unless I get an 85F-plus day in November (not looking likely up here) I'll probably wait until summer to see if I even need it.
Thread Starter
Intermediate
Joined: Jan 2013
Posts: 47
Likes: 0
From: Leominster MA
It seems that when I run richer I can get away with something close to the crazy stock advance curve without accumulating knock counts. I was fairly horrified when I looked at the advance curve (I'm using apyp but true for anything I saw) so I backed it down, but that also contributes to high temps. So it's almost back up to 'normal', and the richer operation seems to quell knock. I suppose my mileage suffers, but I didn't get the car for mileage anyway...
BTW, some of the things you find... after jumping through hoops to cool the oil, I noticed the other day that my dipstick shaft was pressed up against the AIR tube (which is not in use but sure gets hot). I moved it off a bit and voila, my oil temps around town seemed to drop a good 10* from what I'd been seeing even on cooler days.
BTW, some of the things you find... after jumping through hoops to cool the oil, I noticed the other day that my dipstick shaft was pressed up against the AIR tube (which is not in use but sure gets hot). I moved it off a bit and voila, my oil temps around town seemed to drop a good 10* from what I'd been seeing even on cooler days.
