1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

The Great RX-7 Rally Car Build!!!

Old 04-15-10, 11:44 AM
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[youtube]http://www.youtube.com/watch?v=OfA7P3rfaA4[/youtube]

more motivation
Old 04-16-10, 04:37 PM
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OK I just tried Sterling's 10-step on the idle and I can't figure it out. I can get it to idle at 1k (roughly). Maybe 900 with precise adjusting of the two screws, but it's rough either way.

Would not having any vacuum to the leading/trailing advance things on the dizzy contribute to the power loss too?
Old 04-16-10, 04:45 PM
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Originally Posted by dre_2ooo
OK I just tried Sterling's 10-step on the idle and I can't figure it out. I can get it to idle at 1k (roughly). Maybe 900 with precise adjusting of the two screws, but it's rough either way.

Would not having any vacuum to the leading/trailing advance things on the dizzy contribute to the power loss too?
yes, when you gutted the rats nest you need too the vaccum advance to one line and connect it to the 2nd nipple from left to right looking at it from the driver side, you should be able to get it to idle at around 800-750 if you have no vaccum leaks
Old 04-16-10, 06:56 PM
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When i timed my engine, i forgot the hook those vac lines back up at first. Couldn't give the car any gas or it would just die. So yes, they are VERY important.

Also, i would REALLY time the motor before you tune it. You won't be able to tell if the "rough idle before it dies" that sterling talks about is a result of the lean mixture or the ignition being too far off.

Last edited by FunK73; 04-16-10 at 06:59 PM.
Old 04-20-10, 02:45 AM
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any progress towards making it rally legal?


(<-- rally car build in progress in my own garage)
Old 05-09-10, 02:52 PM
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NO! Because I can't get this car to run right! I have spent hours now trying to get it to run right.

It won't hold idle below 1k. I used Sterling's guide to no avail. The idle is lumpy.

It doesn't have near the power it should. It sounds like it's gasping or gurgling when trying to rev or accelerate over 2500 RPMs. I have adjusted the timing from advanced all the way to retarded and not much difference.

The vent solenoid is vent hole is now uncapped. I ran vac to the vacuum advances for L/T on the dizzy. The teeter-totter is good. I have quadruple checked for vac leaks and spraying starter fluid all around doesn't smooth/raise the idle.

I'm about ready to just give up on this goddamn car!
Old 05-09-10, 03:19 PM
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Originally Posted by dre_2ooo
NO! Because I can't get this car to run right! I have spent hours now trying to get it to run right.

It won't hold idle below 1k. I used Sterling's guide to no avail. The idle is lumpy.

It doesn't have near the power it should. It sounds like it's gasping or gurgling when trying to rev or accelerate over 2500 RPMs. I have adjusted the timing from advanced all the way to retarded and not much difference.

The vent solenoid is vent hole is now uncapped. I ran vac to the vacuum advances for L/T on the dizzy. The teeter-totter is good. I have quadruple checked for vac leaks and spraying starter fluid all around doesn't smooth/raise the idle.

I'm about ready to just give up on this goddamn car!
time to try another carb, or some different idle jets
Old 05-09-10, 05:08 PM
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QC

Hey Dre,
Just wondering which category of group 2 are you planning to enter? Also which rule book are you reading from because the CARS (Canadian) rulebook has some differences to the SCCA rulebook. But that's only if you want to rally in Canada and the US. I'm only wondering because I may be allowed to run a S4/5 13B N/A and tranny in the FB chassis under the CARS rulebook, but i would have to confirm on that with CARS themselves. It may be worth asking SCCA if you are able to do that as well, but it somewhat depends on which category you want to run.

I too am building up a rally car, an 85 GS. I will post some pics when I find the cable to plug my camera into the pc.

keep up the good work, looking forward to seeing the car finished, and hope this helps some,

Chris
Old 05-20-10, 09:37 AM
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In the US, there is only one group2. I am running Rally America rules, not SCCA. I am so frustrated trying to get this car running right. Let alone all the work that will come turning it into a racerar!

Is there anyone in MN who knows these carbs inside and out? Like I said, it idles high, lacks power everwhere, and over 2500RPMs (under load) it's like it's struggling to breath or something --sounds like gurgling.
Old 05-20-10, 05:28 PM
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Does your carb still have it's shutter/coasting valve? Mine stuck open awhile back and was running a lot like how you describe yours. What part of the Twin Cities are you in?
Old 05-23-10, 03:27 PM
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Don't give up. I started from the ground up and i'm now on year two of my gsl-se build. Things seem to crap out right when it's almost road worthy... I'm also having a very hard time tuning my holley 650 on my 6-port(overkill?).
Old 05-30-10, 06:54 PM
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Originally Posted by [robert]
Does your carb still have it's shutter/coasting valve? Mine stuck open awhile back and was running a lot like how you describe yours.
I just rebuilt my carb twice. Checked compression. Checked ignition. Checked for vacuum leaks. Happened to put my finger over the hole to the shutter valve and ta da. I found my culprit.
Old 05-30-10, 07:27 PM
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yeah, plug the shutter valve in the air cleaner "floor" with your finger and see how that goes. You can usually pick one of those up at a J/Y for about a whole dollar!
Old 12-25-11, 02:55 AM
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updates?

have you considered just running group 5?
Old 12-27-11, 11:49 PM
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Originally Posted by dre_2ooo

Is there anyone in MN who knows these carbs inside and out? Like I said, it idles high, lacks power everwhere, and over 2500RPMs (under load) it's like it's struggling to breath or something --sounds like gurgling.
I bet it's low fuel pressure. Need a gauge while you're driving it. And a wideband air/fuel meter. Get data, stop guessing. Have someone rebuild the carb.
Old 12-31-11, 03:22 AM
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Hey Dre,
I just discovered this thread which, so far, has been great!

I'm also working on an FB rally car so it's fun to see other guys out there with these things.

I have noticed that it has been over a year since you've posted an update. Is the project put on major hold? Have you just gotten lazy with updating? Did you give up?

Wishing you luck,

Evan
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