BUILD-OFF CHALLENGE: Tygaboy's '75 LS3, It seemed a good idea at the time... Options

[Krieger]

Chris, how much are you paying him? (IMG:style_emoticons/default/biggrin.gif)

[tygaboy]

V2 exhaust system essentially done, complete with peek-a-boo of the end of the trans/muffler mount. Hopefully, Pete @horizontally-opposed will approve! (IMG:style_emoticons/default/happy11.gif)

I still have some final welding to complete but it's drive-worthy so tomorrow, I'm back to prepping for the next trip to the tuner.

[tygaboy]

The new version of the muffler mount is more visible, but you sorta have to know to look for it. Yes, I know, there's finish welding to do on this piece.

And re: that other pic? Well, it wouldn't be a Tygaboy production with out multiple versions/test pieces...

[strawman]

I really enjoyed meeting you (briefly!) at the WCR in Petaluma, and your build is EPIC! One thing you might consider doing is beefing up your trans mount... see the carnage my Suby-powered engine caused to my chassis beginning on post #444 at Suby-engined rustoration. Your engine surely puts out more than my 302whp...

[horizontally-opposed]

(IMG:style_emoticons/default/chowtime.gif)

[Cairo94507]

That looks very nice. (IMG:style_emoticons/default/beerchug.gif)

[tygaboy]

I really enjoyed meeting you (briefly!) at the WCR in Petaluma, and your build is EPIC! One thing you might consider doing is beefing up your trans mount... see the carnage my Suby-powered engine caused to my chassis beginning on post #444 at Suby-engined rustoration. Your engine surely puts out more than my 302whp...

@strawman - Good meeting you, too! Your build created quite a stir. Everyone was talking about how fast that thing is...
And yes, I've been noodling on that same cross-brace mod you did. Seeing the carnage on yours, I'm thinking I should get after that update sooner rather than later. Thanks for the poke!

[djway]

So no crossover anymore? Is there a performance advantage?
Also you mentioned a while back using a manifold and a center mount TB. Can you elaborate more about that?

[cassmcentee]

Crisp and Clean! That looks so good Chris!
Congrats

[tygaboy]

(IMG:style_emoticons/default/blink.gif) (IMG:style_emoticons/default/screwy.gif) and a little bit of (IMG:style_emoticons/default/headbang.gif)

Let's start with the "bad" news:
In testing out the new exhaust, I uncovered an issue I created that, surprisingly, went unnoticed not just by me, but by everyone who has heard the car run.

Turns out I had switched two of the coil connector harness plugs: # 6 and #8. This error was in play in each of the driving videos I've posted. I'm certainly not saying someone should have noticed, it's totally on me but, can you believe it?
Go back and watch those videos... And a few of you heard it run when you were at my shop during WCR.
I would have thought it'd have run like total crap. Note that I have a single O2 sensor that happens to be on the 1-3-5-7 header so the tune wasn't aware of the problem.

Now the good news:
With everything correctly connected, I took it out for another test drive.

HOLY.
MOTHER.
OF.
GOD.

This thing is now scary quick. Well, when it hooks up, anyway. I wasn't even hard on the gas, more rolling into it and it's breaking loose easily through 3rd. I decided not to try 4th.

Remember, this is still with a tune that isn't optimized for the new throttle bodies, throttle cam, correct firing order ( (IMG:style_emoticons/default/chair.gif) ) or the new exhaust.

Am I happy? Yes. Am I a little afraid? Yes to that, too.

[Cairo94507]

Glad it was a simple fix and that it now runs the way it should. Better order some new tires because you will surely burn thru the ones it quickly. Cant'e wait until the next time I come up to see and hear it. (IMG:style_emoticons/default/beerchug.gif)

[tygaboy]

So no crossover anymore? Is there a performance advantage?
Also you mentioned a while back using a manifold and a center mount TB. Can you elaborate more about that?

@djway - So the muffler I was using is actually designed to have both inputs on the same end, the outlets on the other, not one of each, as I'd installed it. Watch the video - that I should have watched before doing all that work!

Short version is that the cross over ended up pointing about 50% of the input tubes all but right toward each other. It was surely creating a ton of turbulence that couldn't possibly be helping.

When I fired the new system, there was a HUGE imbalance in the volume of air exiting each side. This was what clued me in to the fact that something on the 2-4-6-8 side wasn't right.

So yes, a BIG improvement! (IMG:style_emoticons/default/laugh.gif)

Re: the center mount throttle body, that was a comment about how to get an LS in a 914 without cutting the trunk.

[tygaboy]

Glad it was a simple fix and that it now runs the way it should. Better order some new tires because you will surely burn thru the ones it quickly. Cant'e wait until the next time I come up to see and hear it. (IMG:style_emoticons/default/beerchug.gif)

@Cairo94507 Michael - maybe I'll get used to it but it really is scary fast. It's BEGGING for an LSD, too. So that's likely going on the list of updates.

[914forme]

(IMG:style_emoticons/default/agree.gif) The LSD should have been on the list from the start. OR (IMG:style_emoticons/default/poke.gif) AWD

[Andyrew]

Great bad news!!!!

I bet that thing FLYS!

I have a new toy that I think you'll like. Well have to get together soon (IMG:style_emoticons/default/smile.gif)

[strawman]

Am I happy? Yes. Am I a little afraid? Yes to that, too.

I feel you! Even after a couple thousand miles, my car still scares me -- but it never fails to give me a (IMG:style_emoticons/default/stromberg.gif) -eating grin. Congratulations! I can't wait to hear/see it. I'll definitely vouch for an LSD; the OBX helical gear setup in my Subaru transaxle is very streetable and hooks up when you want (need!) it to do so.
Geoff

[Andyrew]

I will say one thing about LSD vs Open diff.

With LSD you really have to be able to keep it straight when the tires are spinning and at some point you have way more wheel speed than road speed and thats what gets you in trouble. Your short ratio box helps prevent "Trouble" as it keeps your wheel speed relative...

An open diff you still have 3 tires on the ground maintaining traction, so swapping ends is a lot less frequent of a thing. Just something to consider, I know you'll put an LSD in it regardless. But my open diff stays straight pretty much 90% of the time when Im spinning.

[tygaboy]

I will say one thing about LSD vs Open diff.

With LSD you really have to be able to keep it straight when the tires are spinning and at some point you have way more wheel speed than road speed and thats what gets you in trouble. Your short ratio box helps prevent "Trouble" as it keeps your wheel speed relative...

An open diff you still have 3 tires on the ground maintaining traction, so swapping ends is a lot less frequent of a thing. Just something to consider, I know you'll put an LSD in it regardless. But my open diff stays straight pretty much 90% of the time when Im spinning.

@Andyrew - I spoke with the tuner this morning and let him know about the swapped coil wires. He wasn't surprised that it didn't jump out as an issue and told me about an LS that came to him running with only one cylinder bank firing and that it still ran sorta OK. Weird. Anyway, the car heads back to him in a couple weeks. Weather aside, I should be able to get some actual miles on it at that point and I'll make next step decisions at that point. Plus, what fun is "going straight while spinning"? (IMG:style_emoticons/default/happy11.gif)

[Andyrew]

I will say one thing about LSD vs Open diff.

With LSD you really have to be able to keep it straight when the tires are spinning and at some point you have way more wheel speed than road speed and thats what gets you in trouble. Your short ratio box helps prevent "Trouble" as it keeps your wheel speed relative...

An open diff you still have 3 tires on the ground maintaining traction, so swapping ends is a lot less frequent of a thing. Just something to consider, I know you'll put an LSD in it regardless. But my open diff stays straight pretty much 90% of the time when Im spinning.

@Andyrew - I spoke with the tuner this morning and let him know about the swapped coil wires. He wasn't surprised that it didn't jump out as an issue and told me about an LS that came to him running with only one cylinder bank firing and that it still ran sorta OK. Weird. Anyway, the car heads back to him in a couple weeks. Weather aside, I should be able to get some actual miles on it at that point and I'll make next step decisions at that point. Plus, what fun is "going straight while spinning"? (IMG:style_emoticons/default/happy11.gif)

Its a lot more fun than backwards in a ditch (IMG:style_emoticons/default/smile.gif) ask the previous owner of Dad's car (IMG:style_emoticons/default/wink.gif)

I can't wait to see it fully tuned (IMG:style_emoticons/default/smile.gif)

[horizontally-opposed]

Great news on the fixes and JUICE, Chris! (IMG:style_emoticons/default/driving.gif)

Sounds like you need an LSD and possibly R-compound rubber STAT. A good LSD should help you put the power down but also stabilize the rear end under braking. Be careful with factory LSDs, as some are known for wearing their way into open diffs, and quickly. Long been on my list for the next 901 rebuild, along with short 2-3-4, billet plate, and billet side cover. That isn't gonna be cheap… (IMG:style_emoticons/default/unsure.gif)