That will be very helpful also for people who want to limit the power until they upgrade the tranny valve body (on automatics) as well since 10-12 psi should be able to smoke your tranny clutches in very short order! I know I'd like that option too.

 

I understand OEM tranny will handle 400HP. Is that true?

 

No, not in stock form. I've burned up two with less than that.

I'm currently considering spending $4000 (not a misprint) to bulletproof mine past 400hp.

 

What amount of HPs you had, when you burned it?
We are planning to Turbocharge our Tacoma up to 10psi and then go over 15psi with Forged pistons and conec.rods.

 

A TRD supercharger with the URD kit can burn a tranny very quickly (less than 6 months) if you do a lot of full-throttle 1-2 shifts, that output is around 320hp at the crank I think. I don't think the transmission in stock form can reliably take much more than 250 hp before you need to think about a VB upgrade (about $1000), and when you start going past 350 hp (at the crank) you need to do the work Mark is talking about, around $4000 for a full bulletproofing.

 

Now we have stock differential R&P ratio with 33 inches tires, would it help to protect the transmission changing to a higher ratio?

 

Brian got here first with some good info.

To put things in perspective, the 3.4L on a '96 4Runner is rated at 183bhp (crank). The same engine a bit latter in model years, an/or on the Tacoma is rated at 190ish. I blew my first one running with just a S/C and headers, so I was probably putting about 270 to the crank, somewhere in there. That was also the original tranny, had 100kish on it when I put the S/C on, and I drove it for about 2 years. Slipping started within the first year.

I replaced the tranny about 3 months ago - it was a used one and said to have 70k miles on it, but it's unknown as to what kind of miles. It's totally possible that it was in bad shape to begin with, but it didn't look like it when we put it in.

Right now, the truck has 160k on it, the tranny's about 5k older, and the 1->2 shift is pretty sloppy. I could send out the valve body to be beefed up, but since the plates are already slipping, beefing up the VB will only lock things up tighter and the tranny will _totally_ fail "sooner", and possibly much more dramatically.

HP wise, I'm pushing about 350 right now, and have the toys in the garage to get me to 390-400. If I install those before addressing the tranny issue, I'll burn it up for sure - there's no keeping my foot off of the skinny pedal.

If you're looking to push 15psi then you will most certainly burn up that auto. There's no two ways about it.

fwiw, the forged rods and pistons aren't really necessary. The 3.4L short block is very strong, it's been said to support over 500hp without changing a thing. The issue with putting power into it is getting power out of it and to the drive train.

As an aside, I hope that you've done the research on fuel systems to support the added air flow. If you don't work down that path, you'll burn a hole in a piston while you're torching the tranny.


Wow, ummm, the math would seem to work out that way, but remember, your primary concern isn't the the output of the tranny holding the power, it's the front of the tranny not burning itself up.

Moving to 33's and changing gears is masking the real problem... you need to reinforce the tranny.


Also, if you haven't found it yet, check out the Custom Tacos forums. Those guys are more into turbos than we are since they're into making power on the streeet. This forum is more dirt aligned so we stick to superchargers.

 

Thank you. Great info. we will have to bulletprof the transmission or set up a conversion to manual.
Does anyone have a Ph. number of URD to ask about, if their Fuel upgrade Kit will be enough to work with 8 to 12 turbo boost?

 

Drop 'em email, that's the preferred way of contacting them:

http://www.urdusa.com/contact_us.php

 

If you are talking about the S/C fuel upgrade kit with the 318's and walboro 190 pump, all I could run was 6-7 lbs of boost (temp outside was in the 60's)

The port fueler, however is a different story. When you get into boost, you will be firing the 6 stock 240cc's as well as the 6 additional 30# (360 ish cc's?) injectors. You will have no problem running 12lbs of boost even on a cold day. Right now we are tuning and have no problem keeping the afr's steady in the high 11's at 12 lbs I don't think that they have the port fueler on thier site yet but I know that it should be very soon..

 

Mark i have to disagree with your thoughts on your tranny right now...

I have 250k on my taco, s/c'd at 186k...i drove for 20k and i DEFINATLY noticed the tranny begin to fall apart so i got the money together for a VB upgrade (Jon at ITB rocks! ) and now i am 40+k with the tranny and the vb upgrade with zero issues...the slipping went away (and it was BAD the tranny wouldnt shift fast enough and it would hit the rev limiter and then DROP it into the next gear)....
The VB upgrade will save your tranny...

I agree tho on the fact that the bottom end on the 5vz is pritty damn solid....how much so...will find out soon...
I am just putting together a mr2 here in the shop that will be running 14-15psi from a T61 on a stock block (except running S2S 268deg Turbo Cams)

We are looking at 400-500whp and a redline of 6000-6500rpm....
Will see!

As for fuel...255lPH walbro and 680cc's....Should do the trick

 

400-500 whp!! That little mr2 will haul and be alot of fun. Are you going to be running standalone fuel managment? That's the way to go but way out of my capabilities to set up and manage.

 

Hey Johnny... are you near a phone? Can I bug you for a bit? drop me a # in PM or email (mark @ midiwall.com)


THANK YOU!

(btw, those aren't really my thoughts - those were John's words to me on the phone)

 

You got pm....

Odd because the tranny is holding up strong...and im surprised i abuse that SOB all the time....to bad the s/c packed it in

 

Yea its gonna be great to see what it can do...only a couple weeks out...

The stock ecu has to be rmeoved due to the redline increasing otherwise i would have went with a SMT7 for sure.

I am using Perfect Powers new XMS unit and testing it out to see if it works out well. I also have a couple other standalones that I am working on getting as well as a plug and play system for the 5vz's all years all trannys...

 

Greedy posted up some pics over on CustomTacos:

 

Looks good.

Not sure if you guys have ever seen or heard of this company, but they have been around for quite some time. They have been turbo charging tacoma's and tundra's for a while as well.

http://www.ststurbo.com/

Check it out. A pretty interesting read, but a little on the expensive side. Anyway, Keep up the good work. Look forward to seeing the end result.

 

There are plenty of posts on this board about STS. Majority of folks(including me) do not want to run it. Too much potential for off roading damage and way expensive. I see you are a newbie and from UT, affiliated?

 

Welcome to YT!

Yeah, we know about STS, but the problem with them happens to be their claim to fame. Their "remote mounting" concept doesn't work well when you're talking about trucks that play in the dirt - our undercarages take quite a beating. STS is more popular over on CustomTacos.com where most of those guys are looking for street power.

 

Thanks for posting that up Mark! And thanks Captain for the compliments. Yeah, everybody here who is interested the boosting thier truck is pretty familiar with the sts product. For myself, it leaves a bit to be desired - hence this ungodly long project Almost done though!