Author Topic: Specialist Components 45 mm Throttle Body (Read 1506 times)

tmsmini · « **on:** November 08, 2019, 11:28:02 AM »

I wanted to install the firewall cover plate and I thought it would be a good time to swap out the 50 mm TB for the 45 mm TB.

The two are not mixing, but it would not have worked with the 50 either. The supplied air cleaner bows into the firewall opening and with the plate in place, the foam air cleaner hits the cover plate.The air filter has to slip past the throttle body assembly to clip onto the bottom of the air cleaner plate and then lock in place.

I have never liked the air cleaner. The setup calls for the breathers to be returned to the air cleaner, but they made their way into the driver compartment. I added a PCV valve dumping into the inlet manifold and wanted to add the cover plate in an attempt to resolve the fume issue. There are not many alternatives for air cleaners. I would love to figure a way to fit an HIF style or MPi style cleaner, but the clearances are tight.

MiniDave · « **Reply #1 on:** November 08, 2019, 12:13:03 PM »

Just the foam is touching, right? Does that matter?

tmsmini · « **Reply #2 on:** November 08, 2019, 01:34:21 PM »

There are plastic supports under the foam. I cracked one of those while trying to ease it into position. Nick Upton fine tuned the original installation and made a custom mounting plate with a spacer to get room needed to fit the foam filter on. I am gong to try to modify that to make it fit. I will get some photos eventually. It will still be tight.

94touring · « **Reply #3 on:** November 08, 2019, 02:17:35 PM »

Those filters fit extra tight. Not sure if you said or have one, but an adjustable engine steady seems to be the fix to gain space with those filters.

tmsmini · « **Reply #4 on:** November 08, 2019, 02:35:26 PM »

I am actually using the MPi style which longer. I will check the adjustable version to see if it extends longer than the MPi version.
Then of course the exhaust tips up towards the body which causes other issues.

tmsmini · « **Reply #5 on:** November 08, 2019, 04:29:29 PM »

Anyone have any idea where to get the smaller OD lock washers? or what they are even called?
The flange for the smaller throttle body is smaller and normal washers hang off the edge.
They use cap screws to attach the TB to the inlet manifold and these washers with them.

jeff10049 · « **Reply #6 on:** November 09, 2019, 12:01:39 AM »

the split type you probably won't find in a smaller od. Look at internal tooth lock washers or serrated lock washers they will be smaller od. They work just as well maybe better.

Smaller od split type exists I have seen them but never been able to buy them. No one seems to list such a thing.

tmsmini · « **Reply #7 on:** November 09, 2019, 09:43:42 AM »

Thank you gentlemen.
They use the serrated version on the smaller cap screws

jeff10049 · « **Reply #8 on:** November 09, 2019, 10:30:40 PM »

Cool I just learned the term for the smaller split type. High collar

tmsmini · « **Reply #9 on:** November 09, 2019, 10:33:35 PM »

The serrated ones are Nord-Lock washers:
https://www.boltdepot.com/Nord-lock_washers.aspx

tmsmini · « **Reply #10 on:** November 10, 2019, 11:04:04 AM »

It is not pretty, but it will work.

MiniDave · « **Reply #11 on:** November 10, 2019, 01:41:12 PM »

Just clears, doesn't it? well done!

tmsmini · « **Reply #12 on:** November 11, 2019, 06:59:53 PM »

Now the hard work starts. It starts and runs, but I need to find a starting MAP for this configuration.
I also added a PCV valve which adds its own issues.
Eventually get it to a tuner to fine tune it.

MiniDave · « **Reply #13 on:** November 11, 2019, 07:14:02 PM »

Seems like the only way to get it close is on a rolling road, or maybe driving around with a buddy who knows how to do the maps while you load and unload it the engine?

tmsmini · « **Reply #14 on:** November 11, 2019, 07:19:58 PM »

You really need a rolling road/dyno and an operator that knows the system.
I got it set up originally, but there were a lot of issues and configuration updates.

This is Renee’s “winter” car, so I need to get a move on.

94touring · « **Reply #15 on:** November 11, 2019, 07:32:48 PM »

On my rx7 with programmable computer I'm able to drive around and watch a tracer on the maps and adjust fuel accordingly. I have a wideband installed and just add or subtract to get the desired ratios.

tmsmini · « **Reply #16 on:** November 12, 2019, 12:42:50 PM »

SX Tune software allows you to update the MAP following the cell tracer as well. But there are times when it is helpful to be able to hold a station and see what is happening to other sensors.

The wideband installation on our engines is installed in the manifold where the narrow band was used in the MPi and SPi. This may not be the ideal location for a wideband reading.
SX Tune also has some idiosyncracies. There was some additional configuration aside from the fuel and ignition maps that might need adjusting.

Theoretically it is possible to extract just the fuel map from one calibration to another. I will soon find out as there is a 45 mm calibration file still on the SC website.

tmsmini · « **Reply #17 on:** November 12, 2019, 05:38:08 PM »

I was able to copy just the fuel map into the existing calibration file, but now the wideband is acting up. So either I disturbed some wiring along the way or the sensor is dead.

94touring · « **Reply #18 on:** November 12, 2019, 06:02:19 PM »

Very similar to the ecu software I use. Only things I really had to adjust on mine were fuel, timing, and injector sizes. The cold start, water temp correction, air temp correction, ect ect maps were all fine from the base map. I did eventually have to expand the fuel and timing maps out to account for running a boost higher than the maps were set for.

tmsmini · « **Reply #19 on:** November 13, 2019, 03:53:53 PM »

Back to basic setup. I fixed the wideband issue. All the wiring checked out so I installed a new sensor. That part is working now.

I am having trouble getting the idle to calm down. I also added a PCV valve which is probably contributing to the problem. It is a valve Moss sells for Mikuni carbs as they have no provision for breathers like an HIF carb. SC has the breather venting into the air cleaner, but with just the foam air cleaner we got a fume smell in the cabin and I though that was a possible source. The cover plate should help and I would like to keep the PCV valve.

tmsmini · « **Reply #20 on:** November 14, 2019, 11:45:40 AM »

Idles OK:

But after a drive around the block the idle jumped to 1250, more trouble shooting...
And the electronic gauges acted up when I switched on the heater fan...more fun

94touring · « **Reply #21 on:** November 14, 2019, 12:21:48 PM »

Lambda 1.0 is 14.7 afr, which is a tad lean at idle, at least on any of my cars. I idle closer to 12:5 or lambda 0.85. Might help settle your idle down, which may be hunting for fuel at idle causing the fluctuation you're seeing.

tmsmini · « **Reply #22 on:** November 14, 2019, 12:40:03 PM »

Supposedly there is a way to update multiple cells in one action. It looks like it is lean at many stations. Plus it was even more lean this morning after it finally warmed up.
I did get rid of the air in the cooling system finally as the heater was only warm yesterday.

I plan to sort out the gauge issue and then get back to looking for inlet leaks. At least it runs with the new TB.

94touring · « **Reply #23 on:** November 14, 2019, 12:59:35 PM »

Being able to select multiple cells and increase in 3-5% increments is an easy way to do it. Then I drove around in tracer mode and tweaked individual cells that were outside a target range. My cold start maps on my rotary are relatively rich under load till my water temps get up to 180f, then things act normally. With all the factory idle sensors and extra crap off the engine it took a bit more idle tuning initially. With a leaner section above idle and as the car warmed up driving, it wasn't unusual for me to suddenly idle near 2k rpms. I could blip the throttle and get it to drop back to 1k rpms. Once I brought the fuel richer in those 2k rpm cells it would get stuck in and found a fuel ratio at 1k rpms the engines porting was happy with, the rise went away.

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Author Topic: Specialist Components 45 mm Throttle Body (Read 1506 times)