Tweaks Re-build thread

[TominMO]

We are trying to get a little convoy to roll out all the way across country, from San Diego to the outer banks. Still in the, " is this possible" planning stages.

Very awesome road trip! Gotta do it!

[blake4591]

It is an AGM battery and yes they do have some different charging characteristics, but I've been using the same design battery for 4 years in this car and I've used similar AGM batteries in other cars with no issues. This is the second battery in Tweak in 4 years because I let the first one (expensive Braille) sit unused for to long (9 months). They don't like to sit without a trickle. I put over 60K miles on Tweak, over half of that on the race track running high rpm, with no alternator issues. I have found that most alternator issues can be traced to grounding problems. All the wiring in Tweaks engine compartment is custom and the battery and starter are directly wired like VW does it. Basically the starter is the junction for all the high amp circuits. Then, all the individual components are well grounded. I used the original 93 festiva alternator in Tweak, but I made a custom under drive pulley because I have no a/c and no stereo, so I didn't see the need for the alternator to spin at a stock speed. The alternator in Tweak is still working perfectly to this day. I've seen regulator failures like you've described on unmodified vehicles with good wiring, so it can happen even without an AGM battery. It does make a mess though. Keep in mind that the regulator does it's job two ways, by regulating the field coil voltage and by dumping excess voltage to ground. Both of these functions are very dependent on a proper ground. Not saying yours wasn't grounded properly, just explaining why regulator issues are more often than not a ground issue, then they fry the battery, or just don't charge at all. The AGM battery may not have been as good of a buffer to protect your electrical system, but that's what fuses are supposed to do. Either way, I have seen that happen before, a few times, with traditional lead acid batteries.
I had the new owner take a bunch of pictures of the battery and tray, but we're having some upload issues. I'll post them as soon as I can.

This sounds a lot like the older Ford and GM practice of using the starter solenoid post to split all the power circuits. I've redone all the wiring on my fox chassis wagon and ended up doing the same thing to prevent the rats nest of wiring on the battery post that seems to be all too common on older cars. When I move the battery I'll be cleaning up the wiring in my festive and probably doing the same thing again. I've always thought good practice is to run a mega-fuse between the alternator supply and battery to have some protection form a regulator failure. I don't know where you would find a megafuse that is only 65 or 70 amps, to use with the 50 amp Festiva alternator.

I'll also agree that at least 60 percent of all electrical problems I have ever had to deal with are ground related. The more you do to make sure all the grounds are good, the less random problems you'll have.

[Advancedynamix]

We are trying to get a little convoy to roll out all the way across country, from San Diego to the outer banks. Still in the, " is this possible" planning stages.

[TominMO]

"I drove it across country and back twice, and it'll most likely be doing that again this year."

Charlie, does this mean that you, or the new owner, is bringing it to Madness?

[Advancedynamix]

I looked really close at that picture and it looks like that battery was an ETX12 with 180 CCA. I think I could get by with that during the summer but I'm pretty sure I'm going to need more than 180 CCA for the winter in Michigan. Luckily Batterymart sells other batteries in the same line that are up to 400 CCA; they are only about an inch taller and are still under $100. I' ll have to measure to figure out exactly how much battery will fit though.

I'll probably go ahead and make a mount since the only ones I saw on ebay were either more than I want or just plastic boxes from motorcycles that would be a pain to make work.

Yes ETX12. These have a lot higher CCA than what they are rated for. the Deka is over 300CCA and this is the same battery, it's identical. I think they just slap a generic ETX12 rating on it and ship it. This tiny battery spins tweaks engine faster than the deep cycle marine battery I use to jump start and test things. The pulse crank on these AGM batteries is unreal. I've driven this car in freezing weather before, no starting issues at all. If you have space though you may want to go with a 14 to be on the safe side. This car wasn't a track only toy, I drove it across country and back twice, and it'll most likely be doing that again this year. I daily drove the car for nearly 2 years and I went on lots of journeys, as well as making "fast cars" look silly on the track. I've used this battery to do Comp. tests after break in and throughout the season and I've used it to spin the engine for oil pressure. No problem starting it after leaving the lights on or doing anything a normal car would be used for. Just don't let them sit unused for more than a couple months without a trickle.

Charlie, was that an AGM battery you used? I used a similar Deka AGM battery in my car and was told that could have caused the electrical issues that killed it. Something about how they aren't meant to be charged the same way as a regular battery. The regulator went out in my alternator and maxed out the voltage, frying everything.

^I've heard that too from a recent mechanic school grad (not sure which school). Said something to do with them being charged by PWM and HAD to be kept within a certain voltage and no higher or they'd die quick.

I know more than a few people who use them in traditional older cars and they love them. So IDK. Maybe one of those, 'when you know intricate details about stuff you get anal about it', things.

It is an AGM battery and yes they do have some different charging characteristics, but I've been using the same design battery for 4 years in this car and I've used similar AGM batteries in other cars with no issues. This is the second battery in Tweak in 4 years because I let the first one (expensive Braille) sit unused for to long (9 months). They don't like to sit without a trickle. I put over 60K miles on Tweak, over half of that on the race track running high rpm, with no alternator issues. I have found that most alternator issues can be traced to grounding problems. All the wiring in Tweaks engine compartment is custom and the battery and starter are directly wired like VW does it. Basically the starter is the junction for all the high amp circuits. Then, all the individual components are well grounded. I used the original 93 festiva alternator in Tweak, but I made a custom under drive pulley because I have no a/c and no stereo, so I didn't see the need for the alternator to spin at a stock speed. The alternator in Tweak is still working perfectly to this day. I've seen regulator failures like you've described on unmodified vehicles with good wiring, so it can happen even without an AGM battery. It does make a mess though. Keep in mind that the regulator does it's job two ways, by regulating the field coil voltage and by dumping excess voltage to ground. Both of these functions are very dependent on a proper ground. Not saying yours wasn't grounded properly, just explaining why regulator issues are more often than not a ground issue, then they fry the battery, or just don't charge at all. The AGM battery may not have been as good of a buffer to protect your electrical system, but that's what fuses are supposed to do. Either way, I have seen that happen before, a few times, with traditional lead acid batteries.
I had the new owner take a bunch of pictures of the battery and tray, but we're having some upload issues. I'll post them as soon as I can.

[sketchman]

^I've heard that too from a recent mechanic school grad (not sure which school). Said something to do with them being charged by PWM and HAD to be kept within a certain voltage and no higher or they'd die quick.

I know more than a few people who use them in traditional older cars and they love them. So IDK. Maybe one of those, 'when you know intricate details about stuff you get anal about it', things.

[bhazard]

Charlie, was that an AGM battery you used? I used a similar Deka AGM battery in my car and was told that could have caused the electrical issues that killed it. Something about how they aren't meant to be charged the same way as a regular battery. The regulator went out in my alternator and maxed out the voltage, frying everything.

[blake4591]

Thank you!
That battery is made by Deka. It is a heavy duty powersport battery, equal to a yx12 iirc. I'll look for a better picture of the actual part number. I got that one from Batterymart.com and it was less than 60 bucks. The original battery I had was a Braille racing battery that was 150 bucks and was exactly the same battery, also made by Deka. If your going to use a glass mat style powersport battery in your car, make sure it has the thick heavy duty terminals like this one does, and not the type like motorcycle batteries usually have. The amperage on these batteries is actually much higher than they are rated.
I made the battery box myself, but you can buy nice ones now on eBay. I'll try to dig up more info for you guys.

I looked really close at that picture and it looks like that battery was an ETX12 with 180 CCA. I think I could get by with that during the summer but I'm pretty sure I'm going to need more than 180 CCA for the winter in Michigan. Luckily Batterymart sells other batteries in the same line that are up to 400 CCA; they are only about an inch taller and are still under $100. I' ll have to measure to figure out exactly how much battery will fit though.

I'll probably go ahead and make a mount since the only ones I saw on ebay were either more than I want or just plastic boxes from motorcycles that would be a pain to make work.

[Advancedynamix]

Did you use a progressive water methanol controller, or just a fixed rate pump and injector style setup. And what size nozzle did you use

Snow Performance progressive controller. It's attached to the side of the center cubby. See above picture with the can of methanol. I used the second smallest injector that snow offers. I can't remember the flow rate on it, but I had to special order it.

Advance,

First thank you for everything you've done for this community. I just have a quick question, what battery is that in the pictures of tweak and what mount are you using with it? Is it a Miata battery, or a lawn mower battery, or something fancier? I have a BP swap and currently have a homemade up and over intake to use a factory location VAM and battery. I would like to switch the battery and VAM to clean up the engine bay and that small battery is exactly what I need.

Thank you!
That battery is made by Deka. It is a heavy duty powersport battery, equal to a yx12 iirc. I'll look for a better picture of the actual part number. I got that one from Batterymart.com and it was less than 60 bucks. The original battery I had was a Braille racing battery that was 150 bucks and was exactly the same battery, also made by Deka. If your going to use a glass mat style powersport battery in your car, make sure it has the thick heavy duty terminals like this one does, and not the type like motorcycle batteries usually have. The amperage on these batteries is actually much higher than they are rated.
I made the battery box myself, but you can buy nice ones now on eBay. I'll try to dig up more info for you guys.

[blake4591]

Advance,

First thank you for everything you've done for this community. I just have a quick question, what battery is that in the pictures of tweak and what mount are you using with it? Is it a Miata battery, or a lawn mower battery, or something fancier? I have a BP swap and currently have a homemade up and over intake to use a factory location VAM and battery. I would like to switch the battery and VAM to clean up the engine bay and that small battery is exactly what I need.

[Grey Vw]

Yeah, that's the sticker! Wear it proudly, especially at the age you were when you swapped a car with enough quality to get that. Some people try for years! So Tweak is one of 2, and my bubble isn't burst sharing that list with you, you're amazingly talented and innovative,
.

Wow, that means a lot coming from you. Thanks Charlie!

[bhearts]

Since I chose not to use an intercooler on Tweak, I installed a water methanol injection system from Snow Perfomance. This is where the name "tweak" originated from. Tweak is addicted to Meth, and it causes the car to be quite hyper and do crazy things.


To adapt the Methanol injection to the B6t, I made an injector manifold that goes between the turbocharger and the charge pipe. I made the charge pipe to the throttle body out of 304 stainless steel to avoid corrosion from the water methanol. The methanol tank is the windshield washer bottle from a carby festiva. It has a fitting epoxied into the bottom which goes through a grommet in the body to the pump down below. I mix the water and methanol at a 1:1 ratio and have raced this car hard at 16psi of boost in 100 degree heat with no problems. In fact, it pulls more consistently than cars with a front mount intercooler and no methanol injection. The car put down 180ft lbs of TQ at the wheels on a dynapack with a stock ECU. My favorite part about the system is that it's mostly invisible. The lines and pump are all hidden and I've painted the meth injector manifold and charge pipe a satin black to appear stock. This car causes so much confusion when the hood is popped the track. Most people overlook the fact that it's even turbocharged. I tell them it's a stock festiva motor. haha

Did you use a progressive water methanol controller, or just a fixed rate pump and injector style setup. And what size nozzle did you use

[greywolf200]

You never fail to amaze me man.....wanw

[MiltonHavoc]

In for the next build. Especially since you have chosen the b6d. I can pick up some pointers.
do post pics of the dizzy mod, as ive lost our conversation about that :-(

[TominMO]

O. M. G. That is some serious porn right there.