five7kid

iTrader: (14)

Holley 6210 with CC ignition.

Note: The following is not an emissions-legal set-up. So, don't ask if you need to go through emissions.

Need: External TPS, load on the MCS circuit. If you have TH700, TV cable adjuster for the throttle arm.

What isn't working yet - choke. The hot air port sits just below the secondary throttle shaft. Manual cable isn't a direct attach - still need to work that out.

five7kid

iTrader: (14)

This isn't the final TPS set-up. The one I got had 5 volts between B & C in the "normal" or throttle closed position. The one I ended up using was for a '90 Bonneville 3800.

five7kid

iTrader: (14)

In the "There's no such thing as a bolt-on" department: The fuel inlet on the Holley is closer to the center of the carb, making tweaking of the line necessary. The back port for the power brake vacuum was broken on the Holley, requiring adaptation (not too proud of that set-up, but it works). The cruise control stud didn't have a good place for mounting, cruise doesn't work well. There aren't as many vacuum ports on the Holley, I had to reroute the MAP sensor line to the front of the carb. The TV cable doesn't quite work right at both WOT and idle, so I chose WOT - it shifts late and hard at low throttle. No way to mount the throttle kicker for AC - had to choose for too high idle w/o AC, too low w/AC - I chose too high.

five7kid

iTrader: (14)

Results:

Drove it to work all last week. Idle is great (just as good as the q-jet). Starts okay cold, have to baby the throttle until it warms up a bit. Feels different at low throttle, but mostly you wouldn't know it wasn't the q-jet. Need to tune the primary accelerator pump, has a slight dead spot right off-idle - is fine if you punch it.

My son drove it at the track Friday night. With 3/4 tank gas, 60' was 2.08, with the q-jet it was 2.05 to 2.11, and you never knew which is was going to be. Most common with the q-jet was above 2.1. ET followed the weather, ran a wind-assisted 14.39, backed it up later with a no-wind 14.40 at about 8000' DA. The best was run when almost out of gas and DA about 8000' no wind.

Overall, happy with the early returns. Still need to get a load on the MCS, sets a code after running a few seconds. Planning on using the EGR solenoid: MCS is 23.5 ohms, EGR solenoid is 25 ohms.

Sonix

iTrader: (1)

So.... you've replaced your cc Q-jet with a non-cc carb, and shoe-horned it such that you still use the computer controlled ignition, with a home-brewed throttle position sensor, etc?

Wow, that's.... A lot of work. Main question - why? I thought you were a diehard supporter of the cc-qjet. It doesn't look (to me) that you've gained a lot of performance. Are you expecting more? Was there other reasons for the swap?

Also, couldn't the off idle dead spot be due to primary throttle blade position? ie, open to far or not far enough? (Or is that a q-jet only malady?)

five7kid

iTrader: (14)

Not so much a "shoe horn" job, more an adaptation.

Why? See the 60' times? The q-jet was all over the place, never knew which car you were staging. The Holley follows the weather, which you can dial for. And, other than adjusting the idle, the carb is out-of-the-box at this point - zero tuning attempted.

"Die hard" supporter of the CC q-jet? For the typical street performance car, and if it's what you've already got, yes. But, if you carefully look over what I've said, you'll see that I say DP for manual tranny and strip-primary cars.

The advantages of keeping the CC ignition functioning are: TCC lock-up still works for auto tranny cars without the need for switches, harness changes, conversion kit, etc.; knock sensor still works (for late LG4 and L69 cars so equipped); and the CC ignition is dead steady compared to a centrifugal advance set-up.

As for the off-idle dead spot, the accelerator pump isn't squirting until the throttle gets past that spot, rather the squirting immediately as it should. A simple tuning thing that I simply haven't had time to address.

five7kid

iTrader: (14)

One part I intended to mention was the carb mounting to the intake. Due to the bowl configuration, only studs can be used, and then they have to be the right length. With the standard 1/4" thick gasket, standard studs were too short; and with longer studs and 1/4" thick gasket, they were too long and hit the bottom of the fuel bowls. So, I had to use a standard thin gasket and the short studs.

There might be a stud length in-between, but I didn't have any and haven't looked yet to try and find some. The thick gasket is nice (in concept, at least) for heat isolation. But, it might not be as much of a problem with the Holley as it is with q-jets since the bowls aren't sitting right in line with the intake manifold heat source.

five7kid

iTrader: (14)

Finally got enough time out in the garage to try the EGR solenoid on the MCS circuit. Had to dig the goof-proof tabs out of the solenoid connector, but once that was done, hooked it up and gave it a try - no more SES light. Doesn't seem to run any different, but at least I don't have that SES light mocking me anymore.

Tobias05

hows the transmission like that new carb?

five7kid

iTrader: (14)

It's all in the TV cable. I used the Summit adjuster for the throttle arm. The cable is out a little more at low throttle when adjusted so that it's fully out at full throttle, so it's a little stiffer shifting a low throttle. Other than that, no issues, TCC works fine.

five7kid

iTrader: (14)

I changed the 6.5 PV to 7.5 last night, much smoother off-idle now.

I get a lean O2 under light street cruise speeds from time to time when fully warm, but the engine is running fine, so I don't think I'll worry about trying to fatten it up.

five7kid

iTrader: (14)

Here's a little better picture of the latest arrangement. I wasn't getting full throttle indication from the TPS, needed to angle it a little more and keep it down to avoid the air cleaner.

five7kid

iTrader: (14)

I didn't expect it to run lean stock due to our 5800' elevation, but it has been. So, tonight I upped the primary jets from 60(2) to 62, PV from 7.5 to 8.5, and secondary jets from 83 to 85 (probably should have gone bigger there).

Results with a quick 5 mile combined surface and freeway test drive (with one on-ramp T&T) are much better throttle response, seemingly better power (pulled up to 6000 RPMs with no complaints - next shot at the strip will be Friday), and no cruise surging (wasn't bad before, had to pay close attention to even notice it). Still got a lean O2 SES under light highway and street cruise (65 & 45 MPH, respectively), but not as often or as long as before.

The small primaries are more sensitive to jetting changes than your "normal" squarebore Holley, and the secondaries less. I'll see how it does in the next few days, but I'll probably leave it slightly lean under cruise if the occasional SES light is the worst effect.

Only remaining issue is a slight dead spot off-idle sometimes (not nearly as bad as it was before). I can't seem to get the primary accelerator pump to squirt immediately without losing the .015" clearance WOT, and I didn't feel up to tearing the linkage apart to switch out the pump cam (the TV corrector bracket sits over the screw for the pump cam - guess I should drill a hole through it so I can get at it without disassembly).

Overall, still pleased with the results, even though fuel economy has dropped slightly. Consistency at the track has been worth it all.

327_TPI_77_Maro

iTrader: (8)

It's too bad they don't make a spread bore Holley with a TPS in it. They would sell tons and tons of them. I would buy one and do the same thing you did, dummy solenoid to the MCS. Getting the TV cable right shouldn't take too much other than measuring the travel at the TV mount point on the Qjet, and replicating that on the Holley with your own custom adapter. You do not want to drive with a misadjusted TV, that is a great way to burn up a 700R4 very quickly.