A&Q about 350Z
Q:
Yeah I know, I don't like auto trannys either. But I have an ankle injury that makes it better for me to have an auto tranny 350Z for my daily traffic work commute. Step one of my road to twin turbos was to get the auto tranny built up because the stock unit will not hold up long term to twin turbo power in my opinion. Soooooo finally after 3 and one half months of prototyping work, my auto tranny is fully built all the way and I picked it up today. So far I'd say that even you guys/gals that do not want to go forced induction should really get a good auto tranny upgrade to your Z if you already have what I affectionately refer to as a slush box. There are several shops that can do that for you, but some have not had a real great track records with 350Zs. The factory computer fights you every step of the way. Is it SGP that is real good? I did not use them but I hear they are good. Whew does it make a difference! I now have a 3200 rpm stall speed ultra high performance torque converter, but I hardly even notice a difference at all just cruising/commuting around to work and back. Excellent streetability. It is still the factory torque converter though extensively modified for more clamping force. And they did such a superlative job on my other mods including valve body that it shifts just as smoothly as stock. Just firmer and quicker. It does not bang into gear abruptly as I've heard that some level 10 350Z modifed autotrannys are notorius for. I have no objective experience with level 10 but have heard some complaints to that effect but some good feed back as well.
Mostly I was just going to say in general if you have an auto tranny 350Z anyway, man it sure makes a difference if you can get a good job done somewhere. I am still pure stock (turbos go on next) and the car now comes off the line like a bat outta hell! Day to night difference. My second impression is I've got to get a lot more tire even before turbos. What a hoot! Just what I wanted. I'll try to run some qtr. miles Sunday if the track is open to compare before and after. I had mostly 2.1 sec 60 ft times but some 2.0 sec. times with the stock 17 inch rear tires. In my opinion this is what the stock autotranny should have been.
You don't need to go as far as I did if you aren't gonna be applying massive twin turbo torque to the tranny, so it should not cost that much. (My auto is now quaranteed up to 550 lb ft of torque and it is supposed to be able to hand a lot more than that! To a guy that loves manual trannys like me, this is an ultra worthwile upgade if you are already auto anyway.
The shop I had the work done at does not want their name put on the internet and the kit won't be out for probably several months anyway. But there are several good shops that can probaby do this for you adequately if you aren't going forced induction. Yes I got a good discount for being the prototype, but I was without my car for 3.5 months! It was not supposed to take that long, but 350Zs are a real challenge to take that far auto tranny wise. Man I am really happy as this is the way I wanted my 350Z to feel coming off the line.
Post Edited (Nov 18, 10:36pm)
A:
Auto trannys are so much more expensive to work on than a manual tranny though. I mean, it would cost me $120 for the rebuild kit on my manual, how much money did it cost to rebuild an auto to handle high power? $2000 or more?
I guess if you're injured and its hard to drive a manual, I can see how you can justify the expense. In my case hosever, a manual is just so much more fun to drive and so much cheaper to maintain.
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1985 300ZX n/a
A:
Yes I agree manuals are more fun. Yes it cost me over $2000 so it ain't cheap. But I am not used to being able to break loose the tires while cruising in 2nd gear well after traction has been gained after the 1st to 2nd gear change. By punching it. On dry smooth pavement in a straight line. So it's a thrill for me. It will be interesting to see what my qtr. mile times are now, but it is cooler than back in the summer before the upgrade. So I'll have to take that into account. And I don't think I can run much better 60 ft times before I go to better than the stock tires.
I certainly would not recoommend changing from a manual to an upgraded dauto like mine unless you have an injury or something. But if you already have an auto, it does take a lot of the slush out of it and it's a real must if you intend to go to a lot of additional power.
Post Edited (Nov 18, 10:43pm)
A:
Ran three tenths of a second quicker in qtr. today with the modified auto tranny and no other changes. I figure at least one of those tenths of second was due to the cooler temps. But my auto tranny is calibrated for the future twin turbo install. i.e., I could have had him set the modified auto tranny up for my current stock power and I could run quicker as the car is right now. Istead I told him to set it up for the big power to come - so the engine just does not make the power right now to jump off the line as well as it would if the tranny were opitmized for stock power. So the auto tranny is better right now while I'm stock engine power, but will be optimum for about 450 hp to the wheels. Ran a 13.92 sec qtr. today which is good for a pure stock auto tranny 350Z given the above factors. I also have to get used to launching it some different with this new setup so I think if I had launched it the way I should have, I would have gotten a 13.8 sec. run. Racing is fun regardless.
Post Edited (Nov 20, 4:47pm)
A:
well, awesome. glad to see that all that money was well spent. Happy racing.
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1985 300ZX n/a
A:
Here is the my auto tranny upgrade that several people have asked me to post. I also posted it on another website in response to an inquiry about the SGP tranny upgrades so you'll see that reference in there:
Well I was going to write all this up because several people have asked me to. So I might just as well break down and do it now. My A5T tranny development work took 3 and one half months. NOT a quick fix! So for what it is worth, here are my thoughts and evaluations so far. As I said, I won’t really know anything till I test my upgraded A5T with the APS twin turbos. This is where I am at the moment.
I really don't know how good or not so good the Stillen and SGP are since I have not tried them. I have heard mostly good things about SGP and that is all I know. But one of the posters on the other thread you referred me to said, "Over the phone tonight Ted had said that the SGP unit will make the shifts very harsh and not very drivable for normal use. Is this true?" All I can tell you is that, for me, the deal with the valve body is I want the shifts to be faster and firmer, but still very very smooth. The opposite of the "harsh and not drivable for normal use" set up. Harsh shifts are for kids wanting to impress people with burning rubber and such. Long term, harsh shifts are NOT good for your power train, IMO. That is one of the things that took so long on my tranny work. Gosh he pulled the VB and modified and retested on the car, etc, etc., etc., so and so forth… ad nauseam! ha. I thought it would never end ha. He called me up at one point, and told me that he was not holding my car hostage, ha! My 350Z is a daily driver. I am very aware of fully built racing trannys that are GREAT for the drag strip, but not for the street. I, for one, am NOT turning my sports car into a dragster. I want a sports car with tranny that handles just as smoothly on the street, the tranny shifts better just more aggressively for curves and for all around performance. I want a sports car first and foremost that will ALSO run a quick quarter mile. I have not tested the Stillen and the SGP so I am not knocking anyone else's work. The only thing I KNOW is that my tranny now shifts just like I hoped it would, but I was almost afraid to get my hopes up that it would shift that good. Now that took a LOT of time and testing, whew! That is why it took 3.5 months and I am not sitting here with the APS TTs on my car now. I could have gotten the car back one month or more quicker if I wanted a harsh banging shift. I had rather bite the bullet, take the necessary time, and do it right. My tranny guy and I are in perfect agreement and feel very strongly about this approach. He has over 200 pages of notes he took as he documented this process. We were not looking for a quick fix or a superlative auto tranny for for 350Z forced induction. The goal was always a perfect auto tranny for FI. Right now, hell, it does feel perfect, but I gotta test it with the TTs before I can make any claims. I am just documenting here the approach we are taking and where we are. As I said, until it is done under TT power, it is not done.
But to me it is about an integrated approach. He went all the way through my tranny and upgraded everything that needed strengthening. Not just a VB and firmer shift and call it a day. All this took 3 and one half months after he was already very experienced in building 350Z auto trannys. He just took mine farther. He says this is as far as he can take it.
He addressed all 3 of the main areas of weakness that he identified in the 350Z A5T for FI along with a plethora of little things. The main areas of weakness, now mucho stronger are:
Area 1. The clutches. As I said there are now 3 clutches in the torque converter instead of 2 - called a "triple" disc. Each clutch has far more clamping power than stock. The clutches there now are made from kevlar and supposed to stand the heat much better. He directly increases clutch capacity. More clutch plates. He flew across several states to take personal oversight of the clutch development when the company building the clutches did not send him, after 3 tries!, ha, what they had promised. He is a former U. S. Marine and just that kind of guy. Ha.
Area 2 IDed as a weakness is the input billet shaft. That is now vasco steel rather than stock mild steel. This billet shaft has been tested and has held up well long term at 1200 hp to the wheels in other cars. That is good enough for me.
Area 3 IDed as a weakness: He uses roller bearings instead of the stock plastic washers which is part of the balancing and blue printing process.
Of course he added a good transmission cooler.
Then the VB - He knows our 350Z tranny through and through and he is confident that NOBODY can do the VB like he can. He is a former U.S. Marine from ’91 Desert storm. He strikes me as guy who is tough as nails and will just keep coming till the job is done. He strikes me as a guy who backs up what he says all the way. I have former Marines in my family, I went through basic training under a Marine corp DI, and I work with a former Marine at work turned computer programmer. These guys seem to back up WTF they say and have a quiet confidence based on what they can and do do rather than just talk. If I had to go to war, these are the type of guys I would want to go to war with. Racing is a type of war, ha. When you think about it. Now all that is just my subjective opinion or my bias, you be the judge. He is very confident in his abilities, meticulous to detail, yet he is affable, a great guy to talk to, and as excited about racing auto trannys as a little kid at Christmas time. This was a long hard, often frustrating process and I am more impressed with his work now than ever. After what we have gone through, I consider him a friend. He has a degree in mechanical engineering and you never lose track of the fact you are talking to an engineer when you are talking to him. He builds 7, 8, and 9 second for the qtr. auto trannys all the time for both domestic and imports. His own car is a 10 second big block V8 so I am dealing with a guy who races himself, not just someone who talks about racing. His friend that he brought in to help with the computer interface part has a double master's degree in theoretical electronics and electrical engineering. These are the kind of people I want to have working on my project and my car. I am not taking anything away from Stillen, SGP, or anybody else, and I am not trying to sell anybody tranny work. I am just documenting my thought process, my evaluation of the people working on my tranny, and our approach. He does not even need the business. He has more serious racers lined up for work than he knows what to do with. He operates to a great extent on personal referrals from other customers. He does not even want his name or company posted on the internet. He has told me that after the kit comes out, send him only serious racers, with a good deal of maturity, who are very serious about upgrading their Z cars. I am not getting any monetary compensation when the kit comes out nor do I want any. I had really seriously contemplated never posting about this at all as I don’t want to get into all that arguing about which kit is better. I don’t really care. I like what I have and I don’t really care if anybody else does or not. To me the tranny is just about building a strong foundation before the turbos go on. My passion is the APS twin turbos and boost. But the tranny is one of the keys for sure.
Here are some of the other things he told me about the process of upgrading my A5T: Transmission reseal package. Valve body gaskets, bonded 3200 stall HD converter. Direct clutch friction module. Input clutch module. Modified front brake band. Friction modified transmission fluid. Recondition transmission for hi performance usage. Including strengthening apply hubs by heat treating splines and T.I.G. Welding over plasma and fuse welds where needed, increasing clutch capacity and treating steel plates with Kolene to prevent warping. Valve body modifications to insure proper clamping force to 600 lb ft of torque to the wheels. Machining of center support and installation of roller bearings to replace plastic thrust washers, and blueprinting during assembly.
This is the kind of thorough process that I think is needed for APS TT power in my 350Z. Others may disagree and I’m sure other shops do great work as well.
A:
why wouldn't he want his shop on the internet? wouldn't a shop owner want some free advertising?