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Discussion Starter · #1 ·
Hi,
I just bought my Opel. She's a 1970 OPEL GT. I have a lot of work ahead of me, this I know, but I welcome any advice. One burning question is this: Does the battery hook up like a normal car or is the wiring reversed? If it is hooked up normally, the gauge reads that it is discharging at -30, but everything seems to be working. If I hook it up backwards, everything still works, and the gauge seems accurate. I'm wondering if someone has rewired stuff and I need to start completely over. Any ideas?
My next question, what were the orginal tires on an OPEL? Mine has 13 inch rims, with 175, 70 R13 on the front and 185 70 R13 on the back. The rims have four holes, but are very rusty. Does anyone have any ideas? Finally, when restoring an OPEL, does one want to restore it to original (and is this possible) or to a more modern version?

Thanks from South Dakota
 

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Welcome to the Board!!!! you'll have many great moments while working on your opel... but before you start driving it ,replace the rear fuel vent lines underneath the tire self.... If ya dont you will get sick... :rolleyes: Good luck with your opel and I hope it comes out nice.
 

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P.S. -- WWW.opelgtsource.com ... that place has almost every thing ya need to restore to original or custom.....
 

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the polarity on the opel is just like most any other car, negative to ground, positive to top post on starter. if your amp guage seems to be working backwards, somebody may have just hooked the amp meter its self up backwards, easy fix if thats the case. i can't speak for origional tires sizes, but from your description, you have a stock set of wheels. stock rims are 13 inch wheels/
 

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Stock tires were 165 R 13. That is approximately equal in diameter to the 185-70. Good luck finding tires that size though. 165's are still available; however, they're narrow by today's standards. I run 175 - 70's on my 1970. The speedometer is off by 10% but that's not due to the tire size. If the speedometer is calibrated correctly the 175 -70's should read within 2% of the correct mph. The stock wheels won't handle anything wider than a 70 width.
 

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Re: 1970 Opel GT

First, welcome to the site, and (presumably) to Opel ownership. Second, it is preferred (especially by AR moderators) that technical questions be started in the Technical Forum, under the appropriate heading, and one question per thread so that it will stay "on-topic". Third, the GT forum is intended for questions or facts specific to the GT model, that are not covered in the Technical Forums. Otherwise, we will have a HUGE GT forum, which will make searching for answers to questions pretty darn difficult. OK, the housework and lecture is complete, so...
OPEL GT from SD said:
If I hook it up backwards, everything still works, and the gauge seems accurate. I'm wondering if someone has rewired stuff and I need to start completely over. Any ideas?
What do you mean by "backwards" If you hook the ammeter up in reverse, it will just show a discharge when it is charging, and vice versa. But if you reverse the polarity (positive to ground) of the battery, BAD stuff happens. Could you be a bit more specific? My best suggestion is to get a Factory Service Manual, or at least a good electrical schematic (JJ Wheatley, of DESTEC Engineering, makes a TERRIFIC laminated GT schematic), and then start seeing what is hooked up wrong. The wiring is pretty simple on these cars, but a typical re-wiring job by the PO (the dreaded "Previous Owner") is, typically, dreadful.
OPEL GT from SD said:
My next question, what were the original tires on an OPEL? Mine has 13 inch rims, with 175, 70 R13 on the front and 185 70 R13 on the back. The rims have four holes, but are very rusty. Does anyone have any ideas?
Too easy, and already answered. The stock tires were 165R-13's, which are about a 165/78-13; hard to come by these days. The most popular fitment with stock wheels are 185/70-13, which is a near perfect diameter, and quite decent performance. Some folks do the 205/60-13, but the sidewalls bulge quite a bit with the stock 5J wheels. And the four-hole rims are probably four slots, which means they are from the '69 or '70 model year. The '71 and '72 GT had 15 round holes, while the '73 had four-spoke steel mags.
OPEL GT from SD said:
Finally, when restoring an OPEL, does one want to restore it to original (and is this possible) or to a more modern version?
The BEST things about Opels (and that includes GT's), is that you can do a very nice "original" restoration, and many will admire it. Or you can do a funky, ground effects, 3.4 litre V6 with a Targa top and 17 inch wheels, and many will admire it. Or anything in between. And many will admire it, if any of those are done well. So this group isn't as AR about keeping it "stock" as, say, the Austin Healey folk. Heck, you can't even MATCH engine numbers to chassis numbers, so what's the point?

Anyway, again, welcome.
 

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Discussion Starter · #7 ·
Thanks for the help!

Sorry about the posting rules. Thanks for all the help. I will get started on some of the stuff tomorrow! :)
 
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