Is that lexan replacing the windshield? How much was the weight difference between the original glass and the replacement? Looking good!
Rei Moloon
I did not measure the difference, because the front and rear glass came out with a hammer. But calculations show 65lb difference for all windows. Standard autoglass is 3-1/2 lb per sq.ft 1/8" lexan is 4/5 lb per sq.ft
Got to run 2 times. All the time was consumed by wheelwell modifications and leaking trans cooler lines. Anyhow, with no boost, lifting at the 1-2 shift etc etc the time was 11.8.
Disclaimer: It was filmed and put up by somebody I do not know, so please ignore the "fastest fiero" in the description, I have never said that.
Did you get a chance to weigh the car? Once you start cranking the boost you are going to need the chute!
No, the scales were not there along with our master tech. I already have a borrowed chute, but I am crap at packing it, It finally opened at the return road. I do know, that the weight distribution is about 35/65(by the trailer hitch weight while the car is centered).
Anyhow, i only used about 300hp from the engine, but it has gone 8.9 @ 160 in a 3275lb GN
Got to run 2 times. All the time was consumed by wheelwell modifications and leaking trans cooler lines. Anyhow, with no boost, lifting at the 1-2 shift etc etc the time was 11.8.
Disclaimer: It was filmed and put up by somebody I do not know, so please ignore the "fastest fiero" in the description, I have never said that.
So, another test day and one start. I think I have pinpointed the problem, the torque tries to turn the diff opposite of engine and bends the flip-adaptor plate away from the trans. There is no other explanation to the amount of fluid and no apparent leaks spots. Anyhow half a second shaved again, 11.35 @ 126
So, another test day and one start. I think I have pinpointed the problem, the torque tries to turn the diff opposite of engine and bends the flip-adaptor plate away from the trans. There is no other explanation to the amount of fluid and no apparent leaks spots. Anyhow half a second shaved again, 11.35 @ 126
Making good progress!
Sounds like you need to add a support between the engine and multiple bolts on the differential pan cover. At least they are pointed somewhat upwards to make it a little easier to access them.
Car is definately starting to get the good times. What is up with that 60' though? Car is leaving really soft.
I have DIY transbrake, and tested it for the first times, so I did not spool up much. maybe 3-4psi. This is testing year, so I'm not aiming good times, I'm aiming to test the combo for next year.
Those 3.07's in the final drive doesnt help get out of the hole very fast. And it sounds like the motor is not coming up on the converter at the right RPM'S.
Those 3.07's in the final drive doesnt help get out of the hole very fast. And it sounds like the motor is not coming up on the converter at the right RPM'S.
Oh, it helps alot more than you think it does... Having a really tall gear in a turbo car is great.
So, 10.413 @ 132.13 in Finland, and then the trans chain broke. That's sad for me, since I paid my arm and leg for that trip and entry fees, etc, just to run 3 tenths too slow
Now I need advice: witch 4T6?(hd?) trans has 1" gears? I think I'll try to replace the chain with gear drive using gears from these. The pitch is the same, 3/8 and by my knowledge, the gears in these are interchangeable, (the 33/37 37/33 thing). So I could buy a broken trans, salvage two 35 tooth gears and run them parallel on my 2" sprockets.
By the calculations: TH425 sprockets are 65 toothed, that makes them 7.76" diameter. The chain is(was) 124 tooth That leaves 29.5 tooth of chain between the sprocket centers. That yields to 3.3" of space between the sprockets.
Now, I want the additional sprocket to be on top, not between the two. That should be stronger, since drive gear wants to wedge the third between the sprockets creating a heavy bond and also, the driven gear wants to hold the 3rd in that wedge. For that, the sprocket must be bigger than 28 tooth. 35 seems about right to fit inside the case.
I would really like to know, witch gears cardealer used in his reverse rotation gear drive.
That's.... not physically possible o.o Are we still talking about the THM-425? If so, you've got a record... no-one has ever broken one of these chains before.... ever...
If you've got one of these broken, I'd really like a picture to take back to my Toronado forums, and tell them that. None of our big bad hunks of steel have been able to tear one of these... a tiny Fiero did XD
[This message has been edited by Twilight Fenrir (edited 08-23-2011).]
Im cardealer or was cardealer, I used 4 final drive gears from (if I remember correctly) th125's. I welded 2 gears on top of each other and machined the centers for bearings. Although it worked, I wouldnt recommend going this route. The gears didnt get enough fluid on them to keep them cool enough. Only fluid they was getting was going off the chain. Plus they were super noisy. If it was me, I would just get a new chain. Maybe try to find a one of those chaindrives that they put in the GMC motorhomes that changes the gear ratio.. The th425 chain is super strong, Im shocked you broke one. Maybe yours was or got stretched and had some slack in it. But still it seems that your drum would have broke before the chain, that leads me to think that you had a bad/old chain to begin with..
In the end the best route on running the reverse rotation for me was having custom final drive gears made. I had the same company in India that makes the after market gears for GMC motorhomes (3.50 ratio) make me 6 sets in a reverse rotation pattern of their normal gears. The down side was that it ended up costing me almost $6000.00 for 6 sets. I ended up selling 5 sets of the gears to a company in Phoenix Az that made high end sandrails. The one set I kept I just sold about two years ago along with the th425 that was in my black Fiero to someone in Mexico. I still have 2 complete th425's in my garage but they have the standard final drives in them.
Now that Im done with my Diablo build and all my other projects- Im strongly considering building another Fiero drag car, Im currently looking for a Fiero now. It seems that there has been a few people to finally break into the 10's now so it might be more interesting for me to build something that will go 9's.......
[This message has been edited by diabloroadster (edited 08-23-2011).]
The chain actually is only rated 200hp and I am not the only one who has broken one. One guy built blown bb to a little Škoda 120L and broke 2-3 chains. Finally he built the double chain assembly. This one lasted. Actually, this trans is for sale, but he is asking 3K$ for it and I dont have that right now.
I also need to re-think some stuff and try to move the engine more forward.
I think I have pinpointed the real problem, the chains brake: Chain speed.
The sprockets are 65 tooth on the 425 but form various sources(Morse and Ramsey) I see the maximum chain speed with this large sprocket to be about 3000rpm. That is for industrial long-life duty. Now, the original boat anchors did not rev past 4000 and with no converter clutch, the chain did not see speeds over 3500rpm.
Now, I'm shifting at 7200, that will be about 6500 after the converter that is over twice the rated speed. And, let's not forget that this rating is given with force-feed lubrication. TH425 has some drips but that's all.
I will be pulling the chain in the weekend, and expect to find overheated blue links.
Good news is, I think I have located a spare donor 425, and just might be able to squeeze one more but sadly 1/8 mile event out of the car this year.
Also, the theory is backed up by fact, that it did not broke on shift (my build hammers the gears quite nicely), It broke in third gear at about 6000rpm in constant pull. No shock loads what so ever.
I think the engineers used this large sprockets to get the torque rating up at the BB-s stock torque rpm. So the chain is at it's best working condition at 2000rpm.
The chain actually is only rated 200hp and I am not the only one who has broken one.
i'm going to have to argue that one... The 66 toronado had 370hp out of the box, with 475 ft/lbs of torque, 67+ had the 455, which had even more power. The thm-425 was the only transmission used.
The rpm part makes ALOT of sense though. Still, i'm very impressed, lol
[This message has been edited by Twilight Fenrir (edited 08-29-2011).]
i'm going to have to argue that one... The 66 toronado had 370hp out of the box, with 475 ft/lbs of torque, 67+ had the 455, which had even more power. The thm-425 was the only transmission used.
The rpm part makes ALOT of sense though. Still, i'm very impressed, lol
Just look up from Morse or orter chain dealer. the 3/8 pitch chain in _industrial duty long life_ application is rated 108hp per inch of width.
Anyhow, I peeked inside the cover and the chain has minor damage, the part broke is the bearing holder. After that the sprocket graduately worked itself out of the splines and finally lost power.
So actually, I did not broke the chain just yet
Anyhow, the car will be teared apart for now and will see, what new year brings. I'm done for this year.
So, the full carnage was: forward clutch hub splines wiped, chain stretched and some links broken, bearing block broken.
It is back together now, but no races this year.
I have amused myself with the spare trans valve body, and the full manual variant is almost done. * reverse pattern * no runaway line pressure in reverse * electric transbrake * engine braking in 1st * fits dual fed or not dual fed trans.
Hi how did you hook up the kick down cable from the transmission to the throttle? do you have any photos? I am setting up my thottle linkage on my BMW V12 to TH325 transmission now so any help would be appreciated...
Hi how did you hook up the kick down cable from the transmission to the throttle? do you have any photos? I am setting up my thottle linkage on my BMW V12 to TH325 transmission now so any help would be appreciated...
Thanks
John
TH425 does not have a kickdown cable, it has a vacuum solenoid for that. It does have a electrical solenoid that should be connected to WOT switch, but I don't use that.
Over the winter I reduced weight, cut up front and back halfs, added water intercooling, lost alternator, added mechanical fuel pump, re-plumbed intake and exhaust, and so on. Also, rebuilded the trans with my own new valve body, now i have all the goodies, "Full manual, reverse pattern, w/electric transbrake".
The year started like this:
On the first event, the trans let go, and I decided, I need some CNC work there. New water-cut valve body spacer plate, modified transbrake valve, laser cut gaskets, CNC billet bearing carriers for the chain sprockets. And now it simply works! Also, new CV-axles was made to replace the "welded together" ones.
From the rear, everything post strut towers has been cut off, only outer skin is wobbling there. From the front, I cut off siderails, everything post front axle diagonal braces. Added a bunch of aluminium rods to support the new intercooler reservoir, gas tank and radiator.
The front fenders, nose and bonet were bonded together to form a one-piece nose hel there by 3 dzus fasteners. Also, the nose was bended down almost 8 inches to reduce lifting effect.
Brakes on the rear were changed from the heavy minivan fronts to solid rotor combo with aluminium calipers, brake booster is ditched and 3/4" wilwood master took it's place.
All-in-All I reduced the weight from 2600 to 2380 while gaining intercooling(+50lbs) I still need to lose the original battery in favour of a smaller and lighter racing one, cut up the doors even more, maybe lose something from the gas tank tunnel. The minimum weight in my class is 2250lb for the V6.
I am in desperate need of a 2000-2001 PT Cruiser spare donut rim. It is 15x4", has 5x100 pattern and made of aluminium! I have one, but need other to mount skinnies on. If anyone has one lying around and is willing to remove the tire(to save shipping weight) then please drop me a PM. That would save me additional 20 lb.
Wow still race weight is excellent. You worried about 10-20lbs now awesome.
------------------ DC Plasma 900 Battery HP 1.551 6.321 112mph 9.898 134.4mph Top Speed 155mph in Standing One Mile http://www.youtube.com/dcplasmaracing/
Well, went to 3rd championship event, managed 9.79 @ 145 but blew the engine. The carnage is quite big. I had to go beyond fuel system limit, since was facing a 8.2 big tire car in 1st round. Also got a flying rock to the turbo, so the compressor wheel is shot also. Other damage is one sleeve has 7 cracks, both head gaskets, etc...
Right now, the block in being sleeved/decked/honed, heads are decked, new rings, head gaskets, compressor wheel, etc have arrived.
I wanted to go to the test-and-tune day this Sunday, but 99% will not make it. So sights have been set to go to Finland the week after to get some numbers down on a prepped track.
