ULTM8Z

I abandoned the 4L80E swap (won't go into all the details)...

But I'm now looking at a built 2004R as an alternative to going back to the 700R4 and that stupidly huge spread between 1st and 2nd gear.

I can get a complete 2004R set up (converter and everythign else) for $2400 from Bowtie Overdrives, capable of handling any future 427 sbc I hook up to it.

Question is, what speed sensor do I need to run in order to be compatible with the 7730 TPI system I'm running?

jmd

iTrader: (4)

4004 pulse per mile sine wave.

Aftermarket that threads onto the GM 7/8 speedo gear sleeve is going to be the way to fly.

ULTM8Z

There was no factory electronic speed sensor for the 2004R?

TTOP350

iTrader: (8)

89 TTA used one

On a side note, I have a TTA trans crossmember just sitting around

jmd

iTrader: (4)

It is discontinued by GM and the aftermarket.
The 200-4R speedo gears are available.
The aftermarket sensor is available. JagsThatRun and others.
I have looked a little.

The_Punisher454

JTR also has inline senders that are cable driven.
Then to make it even a little better you just need to get a DRAC and solder on a set of DIP switches and you are good to go for any ratio or tire size.

RBob

iTrader: (1)

First question needs to be asked, are you using any of the digital VSS pulse streams from the '7730 ECM to another device? If so then need to use a magnetic VSS input to the '7730.

If not, can then use either a digital/optical VSS or a magnetic VSS.

The '7730 has both inputs, while GM used the magnetic in the f-bodys so that the ECM provided pulse streams to the speedometer and cruise control.

RBob.

ULTM8Z

The ECM is currently driving the Autometer speedometer

RBob

iTrader: (1)

That speedometer is programmable isn't it? And since the ECM also is, just need a magnetic (A/C output) VSS. The PPM doesn't have to be 4K, with both the speedometer and ECM being programmable in that regard. Even a 16K PPM unit would likely work.

Just check the Autometer speedometer specs for the PPM range that it can handle.

RBob.

ULTM8Z

It's an Autometer Sport Comp II electronic speedo. I'll have to look it up...

I believe I hooked it up to the cruise control output from the ECM (I recall somehow I couldn't get it to work on the speedo output). But I do recall having to calibrate within the ECM pulses/mile value.

MaxpowerTA

I've looked into doing this with my 2004r equipped GTO. The last 2 years of the Cadillac brougham that had a 2004r 90-92 I believe, Came with a VSS that went in place of the speedo cable bullet adapter that is on all the other 2004r's. I think they had the same thing on the 89 Turbo TA's but those are obviously impossible to find. I've been looking for the caddy one in the local pull a part but no luck so far.

ULTM8Z

I think my problems have just been solved. Turns out there is a close ratio gear set available for the 700R4 (through Bowtie Overdrives, whom I've been talking to about the 2004R).

2.84, 1.57, 1.0, 0.7.

I simply rebuild my existing transmission with this gear set and I accomplish the same objective without having to reconfigure anything on the car.

TTOP350

iTrader: (8)

Hope the price has come down on that.

ULTM8Z

Bowtie quoted me $675 for the gear set (worth it to me since I absolutely despise the factory wide ratio). The Stage III 700R4 build is ~$1900, so $2700 doesn't seem to shabby. It was going to be more than that for the stage III 2004R plus all the peripherals to install it in the car (I'm already set up for the 700R4).

TTOP350

iTrader: (8)

That's fairly cheap, when I looked at it, I was quoted something dumb like 1500 just for that. To me, it wasn't worth the 1/2 to a tenth et reduction.

JP86SS

iTrader: (1)

The 4PAC unit from JTR has cable and mag VSS output at 4 pulse per rev.
That's what I've used in my 700 for a long time now.

I need to look into that new ratio set as well. PATC, and Bowtie have some good options available that didn't exist several years ago.
I already had all the tough parts and all roller-ized (close to Raptor 3-4 except planetary sets) The cost have been prohibitive to change it (until now that I've done some damage to my trans before putting it away for the winter)
Did a Naaaaassssty romp getting on the highway and thinking the converter ballooned, and overrun clutches are gone!
It has to come apart anyway now so looking to make it even meaner/tougher.
PATC has it listed at $599 for the 2.84 ratio set.
https://transmissioncenter.net/shop/...t-carrier-kit/
Jp

ULTM8Z

The gears are actually made by Sonnax btw...

I'm about ready to pull the trigger on this close ratio gear thing... my tranny builder said he can get the gear set for a decent price (a little higher than PATC, but I figure with shipping and stuff....) besides, better for him to order everything that way he can warrant it all.

Once he quotes me a price on the rebuild (hopefully it's reasonable and cheaper than Bowtie), I'll likely have him do the rebuild.

He had rebuilt it back in 2002-2003 time frame and it lasted until earlier this year (and they do all the tranny work on Vic Edelbrock's cars, so I know they do a good job.

I put way less miles on the car now, so I figure it should last even longer (though I'm having him build it in preparation for a possible 525-550 hp 427 sbc down the road).

After that, throw in some 3.73's (up from my current 3.42) to get 1st and 2nd gear ratios back to where they were (along with a boost in 3rd and overdrive from where I am now), and boom... this thing should be bad-a$$... it'll be out of control if/when I get that 427 in there!

TTOP350

iTrader: (8)

From what I've heard, those were originally made back when the 700r4 was being developed but they went with the deep 1st instead.

I'd really like to see some solid back to back testing with the stock gears and then the close ratio before I pull the trigger.

ULTM8Z

Looks like about $2k for the tranny with the gear set. Not to shabby! I'm going to go for it.

JP86SS

iTrader: (1)

Can you PM me some info on that.
If it can handle what you are planning, maybe a discount if ordering 2
Jp

ULTM8Z

I'll just post the info here for anyone else's benefit..

http://www.sonnax.com/parts/3734-2-8...ut-carrier-kit

The gear set seems to be constructed with heavy duty application in mind. Sonnax tells me it'll easily live behind my future 427.

I'm not sure about the "volume" discount thing... my tranny builder is ordering mine for me.

Gary Anderson

iTrader: (2)

Am I missing something here? The 3.06/1.63 gearset is a 47% drop and the 2.84/1.55 is a 45.5% drop, virtually the same except for less first gear. A turbo 400 at 2.48/1.48 is a 40% drop. Where is the "close ratio"?

ULTM8Z

Hmmm..... your post got me to thinking...

I had taken the advertisement at face value... saying 11.72% improvement in rpm drop between 1st and 2nd gear.

But plugging the gear ratios into a shift point calculator is only giving me a 3.5% improvement.

Looks like what they're doing on the advertising is saying

3.06 - 1.63 = 1.43
2.84 - 1.56 = 1.28

Then 1.43 - 1.28 = .15

Then .15/1.28 = 11.7%

Which is apparently not correct... For one thing, they're dividing by the wrong number... but in either case, it's not translating into a 11% reduction in RPM drop...

TTOP350

iTrader: (8)

Which may be why some of the people that have them have only reported .05-.1 reduction in ET?