700R4 1-2 shift point - is this normal/optimal?
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Race Director
Joined: Nov 2018
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It's a longer story. I was competing in the NHRA Craftsman ET Bracket series for a couple of years. So they would have something like a 11.00 - 12.49 time class and have say 32 cars show up at every event for the 10 or 12 event annual series. The top two in points get to represent your track in the regional events at all the member NHRA tracks in my Division 7 events. It become costly and time consuming. You have to meet the rule books tech inspections. cage and all SFI equipment including apparel.
So I had a 355 ci and TH350 with 3.55 gears doing consistent 12.20's and constantly changing my dial in time as the track conditions change. You buy a hand held practice tree to work on reaction times and set your slicks air pressure...... I tore up lots of parts behind the engine. I kept putting in better and stronger parts. Well my hopped up TH350 finally blew chunks of busted metal in the pan. The mid 80's rave was the hot rodded 700R4. Very poor internals, but anyway my first Test and tune day was very disappointing. 700's have bad gear spacing, too low of first gear and too high of second. But what really kills them in comparison to the th350 is that they burn up something like 25 more hp. So I was on the edge of not being in the 11-12.49 second bracket. So to prop up the HP loss I installed a 4.11 rear end. Also as a street driver the OD was way too much with 3.55 gearing.
Even with 3500 stall and 4.11 it wasn't a 12.20 car anymore. IMO it's better to be the faster car and let the other car leave first and then run him down at the finish line. So my grand idea was to build a 7500 rpm 383 ci solid roller motor. Then it became an 11.70's winning bracket racer. In final road racing form before I pulled my 434 ci sbc with a 5 speed I clicked off a couple 10.96's at a 4200 foot elevation track that wasn't prepared on road racing slicks
So I had a 355 ci and TH350 with 3.55 gears doing consistent 12.20's and constantly changing my dial in time as the track conditions change. You buy a hand held practice tree to work on reaction times and set your slicks air pressure...... I tore up lots of parts behind the engine. I kept putting in better and stronger parts. Well my hopped up TH350 finally blew chunks of busted metal in the pan. The mid 80's rave was the hot rodded 700R4. Very poor internals, but anyway my first Test and tune day was very disappointing. 700's have bad gear spacing, too low of first gear and too high of second. But what really kills them in comparison to the th350 is that they burn up something like 25 more hp. So I was on the edge of not being in the 11-12.49 second bracket. So to prop up the HP loss I installed a 4.11 rear end. Also as a street driver the OD was way too much with 3.55 gearing.
Even with 3500 stall and 4.11 it wasn't a 12.20 car anymore. IMO it's better to be the faster car and let the other car leave first and then run him down at the finish line. So my grand idea was to build a 7500 rpm 383 ci solid roller motor. Then it became an 11.70's winning bracket racer. In final road racing form before I pulled my 434 ci sbc with a 5 speed I clicked off a couple 10.96's at a 4200 foot elevation track that wasn't prepared on road racing slicks
If you believe the gear spacing on the 700R4 isn't good, any insight as to why they made it like that?
I'm curious what you mean by this. The OD was "too much" in what way?
Also as a street driver the OD was way too much with 3.55 gearing
Last edited by brassplyer; Aug 16, 2020 at 01:26 AM.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Performance motors are higher rpm. Lets say that you have a 27 inch rear tire and 3.55 gearing and a .70 OD You if you could would be doing @195 mph at 6000 rpm. Not going to happen because of air resistance in a c-3 body unless you make lots of power. I was able to redline my vette in OD with 4.11 with 28 inch rear tires.
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