I humbly request information from PACC Racing/The Nelsons.

BENCH RACING/BUILDING AHEAD:

I snagged a caged '87 Mustang roller for peanuts recently and, being a caged roller/former drag car, it's basically a blank slate as far as the drivetrain goes. 

I have a free '79 302 sitting in a friend's shed. (140 hp LOL) That would be the easy button with the built C4 that the former owner of the roller has.

A guy I work with has an ailing '04 5.3 LS he's giving me, if our schedules ever mesh properly. This one would most likely get a TH350 behind it. (again, bench building)

Another co-worker has a 400M, a 460 or two and a 5.0 out of a '93 Mustang Cobra so there's no shortage of cheap engine choices but there are very few cheap transmission options outside of my local junkyards.

Obviously the 5.3 offers the best combination of weight and power potential. But the transmission would be my sticking point. I would like to stick to the $2,018 budget rules just as a personal challenge. Admittedly I'm not the most well-versed person when it comes to GM transmissions.

The Question:

What transmission was in the SR-71 Datsun? What did you do to it to enable it to live up to all of the testing with the turbo LS engines and the nitrous SBC? How about the converter?

Sorry if I missed it somewhere, I've searched but I have very little time outside of work and was unable to locate the info.

I'd just like to come here to say the 460's can be mean motors and well over 500ci.  Also, I'm sort of a ford guy.  

In reply to grover :

That's been a temptation, for sure!

They seem to build tons of power for relatively few dollars. 

Biggest issue with 460s in a fox is headers. There exspensive unless you can build your own. I am a ford guy so id go short deck windsor with a single plate nitrous system

Depends on what you are planning on doing with the car.  Anything road racing pretty much rules out the 400M (oddball motor - 460 weight with 351 power) and the 460 IMHO, unless you do some crazy setback.  302/5.0 and LS are cheap to build, LS might require non-native electronics that might get pricey ish compared to the 302.  

I know the 4L60 will not hold usually up behind a turbo LS (for long), and most drag guys swear by the 4L80 or a TH400.  By that standard, I would question using a TH350 if you are going to slap a turbo on that 5.3.

LS turbo Mustangs are like belly buttons, but if you want fast for cheap, it's hard to beat.  

Barring disaster, the first engine will be the '79 302 with a small cam and either a C4, 4R70W, or T-5. And the car will be a drag racer.

The next engine will be much more powerful and of unknown make at this point. 

I don't mind the belly button thing. 

Being consistent, durable and fast for cheap is the plan! Which is what lead me to looking into Chevy transmissions, which is what I assume the SR-71 had/has.

The Datsun had a TH400 with a transbrake. My dad can speak more to what was or was not done to it. 

One great thing about Chevrolet engines is Chevrolet transmissions (if you are into automatics). 

I have also heard bad things about the 4l60e.

The bone stock th350 that I have in my Studebaker is still running strong (knock on wood). I'm making about 400 whp from an LQ4.

I think you know what my vote is on the engine choice. LS swap all the things.

dropstep said:

Biggest issue with 460s in a fox is headers. There exspensive unless you can build your own. I am a ford guy so id go short deck windsor with a single plate nitrous system

The kits aren't too bad.  Heads get expensive, but that's every motor.  I find the 460 a cool platfrom to build from but the orignal 4 bolts are awfully hard to come by cheap. 

I was looking at this from a purely drag perspective.  sorry about that.  If I was building an autox vehicle then I'd pass on the weight of a 460 platform.  A lot of drag guy do use a powerglide with the 460's btw.  

grover said:

dropstep said:

Biggest issue with 460s in a fox is headers. There exspensive unless you can build your own. I am a ford guy so id go short deck windsor with a single plate nitrous system

The kits aren't too bad.  Heads get expensive, but that's every motor.  I find the 460 a cool platfrom to build from but the orignal 4 bolts are awfully hard to come by cheap. 

Yeah its not terribly priced, but its not the 500 dollar 5.3swap everyone on the internet has cheap. 

dropstep said:

grover said:

dropstep said:

Biggest issue with 460s in a fox is headers. There exspensive unless you can build your own. I am a ford guy so id go short deck windsor with a single plate nitrous system

The kits aren't too bad.  Heads get expensive, but that's every motor.  I find the 460 a cool platfrom to build from but the orignal 4 bolts are awfully hard to come by cheap. 

Yeah its not terribly priced, but its not the 500 dollar 5.3swap everyone on the internet has cheap. 

Don't forget the 800 dollar turbo kit instant 900hp swap cheapness.

I would imagine the TH350 living in the Stude is because of its light weight. Marginal can live if it isn't trying to accelerate a tugboat. The 4L60 is really a 700R4 with is almost a Turbo 350 with overdrive. It could live in a light weight Fox.

TheV8Kid said:

 

I have also heard bad things about the 4l60e.

 

I’ll let you know when mine pukes, hasn’t happened yet.  I plan to find that threshold of just how many 5.3 with 150 shot on slicks quarter mile runs it takes to kill an unknown 4l60e.  The internet experts would probably suggest that i’m on my 10th transmisison by now.  

Congrats on the Mustang purchase.  I think that if I had to start at zero and wanted to build a challenge car it would be a 5.3 turbo fox.  Next to a Camaro/Nova it is the cheapest most well sorted, performance part available platform.  That said, does it have an 8.8" rear?  If not....get.

I am a big fan of the 460.  But...in order to get a trans to work or hold up you will be out of the Challenge due to cost.  And if you are out of the Challenge, the 460 is easy to stroke to over 500 inches.  If you luck out with a trans and able to use at the Challenge, go NOS.  Word of caution, there was a BBF Fox at the Challenge in 2004 or 2006.  The owner had to do a lot to set the engine back.  His demise was his transmission.  IF I built a non Chevy powered Challenge car, a 460 Fox was going to be my poison.

With a SBF, stock ported heads and the right cam makes 360 rwhp easy (BTDT).  Nitrous and you're fast.  Again, the trans will  dictate if it is successful at the Challenge.  The Ford trannies, converters and associated cost make them unattractive.  I have gotten rid of every Ford performance part except one higher stall C6 converter that would work behind a SBF/Nos combo.  BTW, many Ford guys are using T400, T350 or PG transmissions, but its not a cheap adaptation. 

IMO, the Chevy engine is the best choice.  You mentioned ailing so that issue is not considered into anything I offer.  You have to determine if the repair is worth the Challenge cost.  We are building another car and the Nova is on hold.  The other car is a Turbo LS that we want to build and run 10s for under $1300.  We are documenting in case GRM wants to do an article.  If not, we (Fuzzy) will post into the build page.  The goal will be to show the parts needed to go 10s on a budget.  Unfortunately, both projects have been slowed. 

Ultimately, (and finally getting to your question) the Chevy offers the best engine/trans options for projects with a Challenge budget.  We use T400.  Cheap and easily modifiable to get good shift control.  I use the early units from late 66 to early 70 do to the internal parts being stronger.  Don't  touch a 65 or small yoke 66.  While they have a 32 spline output they also have a unique yoke and tail stock.  The 71 and later need more reprogramming and make the 1-2 shift at 5200 without the reprogramming.  But for Challenge money you can get a working T400, drill 2 holes and have a serious transmission.  The T350 is viable, but too hit and miss, and definitely needs more work to hold any real power.  The SR-71D trans was/is a T400 with a brake that has been together since 1989.  We got it through a series of trades and is one of the most common race trannies in the world.  The combo of the Chevy engine with the Chevy transmission is why it is hard to beat for challenge money.  There are a lot of good engines out there, you just can't go quick/fast without the trans/converter working with it/them.  FWIW, the converter is an unknown, but we use it because it only has 4.7% slip which works with the SBC/Nos or turbo....it's tight.

Try to find an early LS1 or LS2 cam.  The Sunbird had a 59MM turbo, LS1 cam, dished pistons and ran 10.8.  We are expecting good numbers from it on the next series of passes.  

Thanks Jed and the Nelsons for making my spreadsheet melt from the working calculations I need to do now. 

I need to put to use the free glide or $25 t400 I got from Patrick..... Converter selection for what I need sucks and makes it pricey.

Ranger50 said:

Thanks Jed and the Nelsons for making my spreadsheet melt from the working calculations I need to do now. 

I need to put to use the free glide or $25 t400 I got from Patrick..... Converter selection for what I need sucks and makes it pricey.

Should not be. If you have a T400 and an 8.8" rear you can use more gear and less converter. That would work well with the 5.3/turbo package.  

Depending on the engine torque, the converter can multiply the torque faster than the gear ratio.  You have to understand that a torque converter is a TORQUE......CONVERTER. Most people say the two word together too fast and think of it a a component instead of thinking of it as a system. 

So you can set up the 5.3/turbo with less converter and more gear....especially as track condition gets worse.  

The Sunbird had too much converter with too much gear and the tires would light up about 15' out.  We were able to prove that out on Fuzzy's 10.8 run.  He did not floor it until 0.93 seconds into the run.  Post challenge we changed to 3.27 from 3.73 and will test.  We may have to tighten the converter and bump up the gear ratio  but that will all be tested out in a few months.  The original set up was for a 4.8 not a 5.3 and we could not make the change in time.  I know..too much blah, blah, blah for this post.  

The BBF and SBF converters are available but not typically Challenge friendly. Last one I found was a 10" C4 that I immediately sold to another Challenge competitor at the purchase price. It was too good a deal to walk away from and passed it along.

That said GM converters are much more available and much more interchangeable. Ford has differences between C4 and C6. GM T350 T400 BOPCC interchange. And many many many PG converters are built with Turbo spline input shafts so they also interchange. Chevy's use one transmission bellhousing pattern. Ford has 5. Even the SBF C4 has 3 different types of bellhousing. I know because I raced BB and SB Fords years ago. FWIW I also raced  Buick, Olds, Pontiacs, and Chryslers. 

In reply to wheels777 :

Didn’t say it was going behind anything already GM... 

In reply to Ranger50 :

Oops.  I just realized I made two replies thinking it was to one person and just realized you are not the OP.

Thanks for all of the info!

I'm done with work for a bit and finally got the chance to read it!

Ranger50 said:

Thanks Jed and the Nelsons for making my spreadsheet melt from the working calculations I need to do now. 

I need to put to use the free glide or $25 t400 I got from Patrick..... Converter selection for what I need sucks and makes it pricey.

I've made a few rear gear ratio/trans ratio/tire size/engine speed = vehicle speed charts with different gear and trans options trying to decide what would be the best option for what I want to do. I've run 3.08 (most likely in the stock 8.8 that comes with the car, the tag is too rusty to read), 3.27 (also a possibility for the stock 8.8), 3.55, 3.73, and 4.10 gears having each in turn mated to a C4, a 4R70W from a '98-'04 SN95 V6, with converter (manual shift conversion with $200-ish kit, OD and TC lock on toggles), and a T-5. Those combos have so far been run with a 225/60R16 (I have a bunch on hand) and 275/60R15, the tire I will most likely use to have the car tuned to a tire that will give us a class to grow into.

I made the first few charts on my lunch break at work, going all of the way up to 7,000 rpm in 500 rpm increments. These are for the '79 302. Instead of writing 6,000 rpm, 6,500 rpm, and 7,000 rpm I wrote RATTLE, CLACK-CLACK, and POOF.

In reply to The_Jed :

I'm planning on a 3.55 geared 8.8, 275/60r15's, and spin it until it breaks.....

In reply to wheels777 :

The TH400 in the SR-71 hasn't been rebuilt since 1989?!

Has it been in various 1/4 mile monsters the entire time?

Have you measured the diameter of the converter? 

The_Jed said:

In reply to wheels777 :

The TH400 in the SR-71 hasn't been rebuilt since 1989?!

 

Has it been in various 1/4 mile monsters the entire time?

 

Have you measured the diameter of the converter? 

Correct.

Yes

10"