Josh's Syclone build thread

[DaveP's Ghost]

Lastly, took the driveshaft and cut half an inch off the slip yoke so that I won't have any problems installing it anymore.

The splines bottom on the INSIDE. Cutting the end of the yoke isn't going to do anything to "help install the driveshaft". All you've done is reduced the area of splines that will be engaged when it is installed. The yoke is still going to bottom in exactly the same place it did before you cut the end off.

 

[Goodgollyjosh]

These are the measurements i took:

5.900" is length of inside of yoke from tip of yoke.

4.456" is tip of output shaft of tcase to rubber bump stop inside tcase. It appears designed to contact rubber bump stop first but i could be wrong.

I'm putting the tcase in today. Should have an answer tonight on this. Thanks for the help Dave. I'll keep you posted.

 

[Goodgollyjosh]

The driveshaft goes in much further now...as far as it possibly could. It doesn't bottom out against anything except the end of o.d. of yoke. Let me know if I'm missing something Dave. Maybe i have an aftermarket driveshaft.

 

[Goodgollyjosh]

Got the tcase installed tonight. No issues with the rear driveshaft, thank God. Also, got the shifter installed and got the shifter cable routed and adjusted properly. I used a 1" thick piece of aluminum to gift the shifter the lift it needed to sit in the correct position. The aluminum is bolted to the gold console support from the bottom and the sides. Feels very solid. I'm so happy with the way it turned out. Other than the shifter, the gauge pod, and the shift light hiding in the cigarette lighter...the interior still looks very stock, which i like. I have a few more things left to button up and then we will hopefully have her on the road again.

 

[dgoodhue]

That sucks about your transmission. Years ago, I rebuilt the 700r4 transmission in my C4 Corvette. I took it to local old school transmission guy, I told him I wanted a basic rebuild with the upgraded clutches and I didn't want a shift kit. My Corvette was mostly stock but my friend mentions that I brought it to the track. Anyways, I goto pick it up and the transmission guy said he did some upgrades and mild shift kit. It would no longer do 3-4 WOT shift (which sucked because I ran out of gear at the end of the 1/4 mile) and the 1-2 was really low, 2-3 was too high and the transmission no longer shifted smoothly. The gut told me to use the TV cable to adjust my shift points.. I tried a transgo shift which did not help, and then I met a transmission guy who was good with 700r4 on online. I probably dropped the transmission pan or servo dozen times. I found a couple hacks and a plugged passage but I couldn't figure it all out. I gave up, bought a used stock transmission and it worked like the original. It is so frustrating.

For my Syclone, I bought a used transmission from a typhoon as core and rebuilt that. While I was rebuilding that, a prior owner mentioned the Typhoon transmission did not work properly. Sure enough when I put it together it didn't work. I spoke to Brian Hartman went over the pressures. He said to swap the valve body and separator plate from Syclone original and sure enough that work. I pulled the Typhoon VB apart but I could never figure it out.

Now that I will be shifting this thing by myself, I am curious what a good safe shift point is on these engines when running the stock internals?

The shift points depends on the engine mods and camshaft. The stock shift points are around 4100-4300rpm 1-2 and 4400-4600rpm for 2-3. If you are still running the stock cam/heads, you might be able to shift it a little higher since your running bigger turbo and more boost.

 

[Goodgollyjosh]

Dgoodhue, I'm glad I'm not the only one who has had hell with the 700r4. Sounds like you know more about them than i did, but i was learning a little bit here and there. Thanks for the tip on the shift points.

 

[Goodgollyjosh]

Truck is running and driving. No issues. Shifts amazing. Feels like I'm driving a standard...a clutchless standard lol. Very firm and strong. I tested the trans brake, works beautifully. The ratchet shifter feels great too. I am now working with Rob to fine tuning this thing. One step forward, two steps back with this truck, always. But, I feel like things are finally headed in the right direction. More to come later.

 

[DaveP's Ghost]

I always think about what I'm posting before I push send. Even though I've had at least a couple dozen of these T-cases apart, I don't remember a "stop" inside the T-case, I recall the next thing the yoke can hit is the reluctor wheel which is pressed on the output shaft. I'm obviously wrong. I don't work on these trucks anymore like I used to. The community of owners in SoCal has pretty much disbanded. I don't hear or do much with the trucks or the guys anymore. I still work on my own Ty which I've owned for 23 years, but it is bone stock, the engine has never been out with 120k+. It doesn't need much, so I don't learn much from it either.

Anyway glad it worked for you. That's a nice Syclone. Good to see there are still some people interested in these dinosaurs.

 

[Goodgollyjosh]

Thanks for the kind words Dave. I appreciate the help thus far with the truck. A lot of you guys have been around these things longer than I have. I'm glad to be among the crowd that is working on keeping Sy/Tys on the road.

 

[2500avalanche]

Looks great!

 

[Mikeysy15]

Wow , congrats on all that work . That shifter came out really nice . Glad to hear everything works at it should . You’ll love that longer first gear of the th350 once you get to the track .

 

[Goodgollyjosh]

Christmas came early. HD front driveshaft. Got the shifter bracket on the TH350 all trimmed up. Been data logging and tuning with Wyosyclone. Nearly finished with pump gas tune, then will start on tune for pump gas with octane boost, then finally a tune with the alky injection.

 

[Goodgollyjosh]

The tuning has been a lengthy but necessary process. A huge shout out to WyoSyclone and everything he has done to help me. The man's wizardry with the factory ECM has been a huge blessing. All the datalogging that I have done has enabled him to catch a lot of things. We have dealt with a whole array of problems. I had spark break-up that led me to making a better ground for my MSD box and ditching the NGK UR6 plugs in exchange for Autolite AR24 plugs that Wyo had suggested. We encountered knock early on in the tuning that had me re-adjusting the exhaust and looking for anything touching or rubbing that might be setting off the knock sensor. Wyo had discovered that my injector voltage was dropping off during WOT pulls and I performed his mod to fix this issue (Wyo will be posting this repair soon). We then dealt with what appeared to be poor grounding issues causing a glitch in the datalogging during WOT. I cleaned every ground connection that I could find and we seemed to have dealt with that issue.

The TH350 trans and it's different gearing caused it's own unique challenges in that a different timing and fueling strategy is necessary because of the different loads it's puts on the engine at different times compared to the 700r4 so you can't simply use a BIN for a truck with a stock trans. 1st gear in particular is much taller. The Royal Purple Octane boost that Wyo had suggested allowed us to dial in a little more boost and timing than we would have been able to use otherwise. The work that he did to cold start, idle, cruise, tip-in, and WOT have all made this truck run so much better than it ever has. I think we are up to 24 different updates to the tune. That is something you simply cannot have with an off the shelf BIN. We have a good and safe street tune now and will begin adding Alky and tune for that as well, we will start turning up the boost and see what she will do. Looking forward to it!

Thanks again Rob!

 

[Thunder_Lloyd]

This is a great build. I've enjoyed reading and learning

 

[Goodgollyjosh]

Thanks Thunder, i appreciate that. A lot of blood, sweat, and tears have gone into it.

 

[Goodgollyjosh]

Before starting the process of alky tuning we ran out of injector with the 50 pounders. Decided to switch to 80 pounders per Wyo's recommendation. This will leave the window open for E85 in the future. I want to get as much out of the street tune before working on the alky tune as possible. In the meantime, I decided to add two more systems to the trans brake button on my shifter. I took the 2 step off the brake pedal switch and ran it to the shifter, it works when it sees 12 volts just like the trans brake. I also ran the purple wire for the alky system to the trans brake button as well. It has a pause feature that will stop alky spray while the 2 step is engaged. However, it works backwards, instead of wanting to see 12 volts, it wants to see ground in order for the pause feature to work.

So, I had to incorporate a relay so that when the trans brake button sends out 12 volts to the purple wire on the alky system, it goes to the relay instead, which I have wired to go to ground when turned on...simple solution.

Also, I have been chasing a small oil leak on the back of the motor, up high along the bell housing area. I have narrowed it down to the oil pressure sending unit or the back of the intake manifold. I tightened the oil pressure sending unit and it's still leaking so maybe the manifold. I'll have to do some exploratory surgery and figure out where it's coming from. But, while I was poking around back there with a mirror to try and spot the leak I discovered that my distributor is an MSD unit....sweet! Thanks previous owner!

 

[Goodgollyjosh]

Oh, and with regard to the fuel pump, i have no idea what pump the previous owner installed. I guess i will know....when i run out of fuel pump. But, I'm sure we'll only get another pound or two of boost out of it before hitting the knock point on pump gas with the octane booster. At which point we'll start with the alky.

 

[Sy2622]

Couple questions??
I am running the same injectors so.
How far did you get (performance wise) before you ran out of injector with the alky?
Boost level?
Timing advance in 1-2, 3-4?
Any input would be appreciated.

 

[Goodgollyjosh]

Hey Sy2623,

We haven't started using the alky yet. But, we started maxing out the 50 pounders at around 15 pounds of boost on pump gas but keep in mind that is 15 pounds with a 62mm turbo so it's making more power than a stock set up. I'm running a th350 trans so the ECM isn't able to keep track of what gear I'm in, that particular system has been disabled in the tune.

I think timing is at 15 degrees right now. We should be able to get some more out of it with the new injectors before hitting the knock threshold, especially with the Royal Purple octane boost on top of 93 pump gas, we should be around 96 octane. The taller 1st gear won't allow as much timing out of the hole as a 700r4 but I can post back with what we are able to squeeze out of the truck before hitting knock and before using alky. My truck has been a little more knock prone than some of the other trucks on here which could be a limiting factor. Could be due to one of the following:

1. The engine has been noisy since I first bought the truck. I don't know the full history of the vehicle, I am finding new aftermarket parts the further I dig into this thing all the time. I have cut the oil filter open, didn't find anything. I also readjusted the lifter pre-load on the comp rockers, sound didn't changed though. Sounds like valvetrain noise. I may do some lifters in the future. This could be upsetting my knock sensor. I know the main bearings love to get hammered out on these things so hoping it's not that, but with all this datalogging and WOT operation the noise has never gotten any worse and I have great oil pressure.

2. The widebody injectors could have been rubbing. There is a GM TSB about widebody injectors making a knocking sound on Sy's and Ty's when the housings contacts the intake manifold. The pics of my injectors in the classifieds section would indicate that they were probably rubbing.

3.I have a torn driver's motor mount. I tried to run the engine torque limiter rod that everybody has but I couldn't use it. The previous owner cracked the alternator bracket and I epoxied it. It holds the alternator fine, but I don't trust it to hold the engine under load. So, I am running an old school chain from engine to frame on driver's side, I could be picking up some harmonics through this.

4. I have a 3" downpipe that is wrapped so it gets close to the frame as does the rest of the exhaust pipe all the way back, I gotta watch interference between the cross members and the pipe and readjust to make sure nothing hits anywhere.

Hope this helps bud!

 

[Goodgollyjosh]

We've been running 90 to 100% duty cycle on the injectors. If I am still having problems after the injector swap then I'm gonna look at the pump, it could be shot or it could be stock. I need to make a longer fuel line for my gauge, it's not long enough for me to view it while driving.