TOPIC: 1992 Saturn 1.9 l SL1

This is my daughter's vehicle, with around 170,000 km on it. I put the new angle groove in it about one week ago. I also re-shaped the throttle plate and polished it. I do not have an OBD 1 scanner, so I do not have the fuel trim info.

The performance from 0-60 before the groove: ~16.4 Secs.; after the groove: 15.5 secs.

Mileage before the groove: 32-36 (depending on how she drives)
Mileage after the groove: pending: gone on a trip into the mountains with a load of people and stuff, with a fairly high average speed (double lane, following traffic). I will post as new info arrives.

Following are pictures of the Intake Air Control passageway re-route:



On the right side of the throttle body, the whole chamber is attached to the IAC passage, with the air entering the throttle body at the notch in the 3 o'clock position. You can see the pintle of the IAC in the upper right section of the large opening. This is the side which must be grooved, so the IAC passage has to be re-routed.


This is a closeup of the same.


Here is the placement of the bypass: from the deep opening right below the pintle of the IAC valve, to the throttle body over the plate axle. There was lots of metal, and so I took it deep and wide so that the opening into the bore was similar in area to the original opening.




The large cavity is filled with metal epoxy (I use Permatex Cold Weld) including the original square air passageway to the throttle bore.



Here is the finished TB with the groove done with about a 25deg angle. The Throttle plate was reshaped and polished.

More results as they come in.

Luke

Hi Luke,

I would have taken a different approach on the reroute.

The IAC opening, would have done exactly what you did, although the reroute path I would have taken would have taken advantage of an existing pathway into the venturi to minimize
the number of openings that would be drawing air in.





It doesn't make your approach wrong, I'm just looking at it a bit differently , I think.

Karl Fortner
Tacoma, Washington

Hi Luke and Karl. Luke that looks like a good fill in job for that IAC area. Groove looks good too! One thing though. I just read the thread about your Jeep and Ron's advice about technique. Did you use the throttle plate as a jig on this TB too? Looks like a pretty good gap between the plate edge and the Groove. That location will make the Groove effect come on well into part throttle, looks like to me.

I agree w/ Karl about where the re/route trench could go, with a question. That small opening Karl drew the red line to--what is it connecting with? Is that a vacuum passage going somewhere,I think I see vacuum hose ports/nipples above that spot in one pic. Might it be an inlet for EVAP fumes from gas tank/charcoal canister? I'm inclined to think it's a Vac. passage,since it's exposed to manifold Vacuum. I'm thinking you made your trench big in view of Canadian winter temps requiring more air for fast idle when cold.

But I say your workmanship looks quite good. Thanks for these pics, they really tell the story. You are helping us all learn! TracyG Gadgetman Reno

Now that's teamwork!

Either will work fine, although I would use the one requiring the least cutting. So long as the air is entering above The Groove, it's going to be just fine.

Looking forward to the results on this one!

Hey Karl, Tracy and Ron,

It's great discussing different views and I greatly appreciate it, too.
The small opening is a vacuum port. I chose the route I did as it was the shortest, and I wanted it to move roughly the same volume of air as the original opening. As far as the distance the groove is from the plate, here is the story:

The jeep is an experiment. I was using the plate as a guide at first as it was the first one I did, before the new angle came out. I was experimenting on it and for me to know the parameters on it and to practice the cuts, I would use the plate as the guide. I wanted to see what would happen to the performance etc. I love experimenting. I have done it 7 times to date on the jeep. When the new angle came out, I started the new angle, different positions etc. I tried the new angle using the plate as a guide, cocked open quite wide to produce about a 28 deg angle, just to see: I had a beautiful groove, but no performance. Anyway, I did several grooves since then on it, and it has the new angle now, as do all the vehicles that I have done in our yard.

In the meantime, I wanted to find a way where I could make a consistent angle that didn't look as though I used my teeth. So, I made a measuring jig that I use to scribe a line on the throttle body so that when the top of the cutter is resting on the throttle plate, the bottom of the cutter is starting to cut on the scribed line, dictating a measured angle, taking into account the angle of the throttle plate. So, if the throttle plate is 13 deg. at rest, and we used the older technique, there would be no gap between the edge of the plate and the cut if you were to use the plate as a template. As we know, when the angle of the cutter is increased to 22.5 to 30 degrees, the distance between the plate and the cut is increased. So, what you see in the picture is in fact a 25 deg. cut from the bore of the throttle body, using the throttle plate as the touch-point. The scribed line gives a point of reference for each cut, and so again, if the top of the cutter touches the plate, and the bottom starts the cut on the line, I know I am at the proper and consistent angle. I like the 25 deg. measurement because it gives more leeway for error without going beyond the parameters.

If you like, I can explain it better with pictures and put it under the proper heading in the forums.

Thanks a lot for your input and your encouragement guys!

Luke

Well explained,Luke!

Could you show us the Jig tool? I understand it's application, it sounds quite useful to enable marking a line setpoint for the bottom of the bit. I just can't visualize the jig itself. I'm sure if ya show us, I'm going to slap my forehead and say, "of course!"

Something like this jig could help me a lot, as I lack Fighter Pilot's eyes...!

TracyG Gadgetman Reno

Hi again Luke! Any news about this Mod? I would dig it if ya could show us the Jig. Any shots of that Rig, they don't need to be that Big...I'd like to see the gig on the Jig...If it's really cool I'll flip my Wig!

Ok enough of that:

TracyG Gadgetman Reno

hey Tracey: not ignoring you: been away: lots going on: will post soon

Luke

UPDATE: The trip to the mountains had some issues, so what I am going to do, as this car will soon follow my daughter back to University, is to do an empirical test on mileage with my plug 'n play auxillary gas tank: an 'after' test, as the groove has been done already, and then a 'before' test, in which I will fill in the groove and retest.

Luke

Update: coming back from the mountains, car had oil loss issues, and the timing chain piled up, therefore no further testing!! Just to note that the improvement with power was noted (ABOUT 1 SEC FASTER 0-60 MPH THAN POST-GROOVE)

If you had oil loss issues, that can only be one of two reasons. You capped off the Breather and the PCV. (don't laugh! It DOES happen!) Either that or this is a high mileage vehicle and the front seal is long past its service interval and is so worn the only thing keeping the oil in the engine BEFORE was the suction from the PCV port.

First, that is VERY bad for your oil as the air is sucked in as the engine runs from around the seal. This will aerate the oil, effectively destroying its lubrication capabilities.

Fix the sea. That'll make everything Hunky-Dory! Until then, you should re-attach the vac line to the PCV. While your mileage may drop, it is far better than losing your engine!

Hi Ron, in a nutshell, the front seal was the culprit, rock hard. Age was against the vehicle. The PCV was routed correctly. The car was loaded, pulling hard in the mountains. I did replace the front seal, and the alternator and the belts etc, in fall after that, but she never did any highway trips after, just short trips and did not check her mileage. There were also over- heating issues that she was unaware of that hastened the demise of the engine. The timing chain skipped a cog in November and the car is now resting in peace!!