Engine, Tranny Mods

[jap137]

[font=times new roman]Hello, people. This is my first post after nearly a month of lurking.

I have a couple payments left on 1996 G20t, then it's let the modifications begin.:sun:

Since I have an automatic tranny, I am seriously considering having the folks at Level 10 rebuild my tranny with their signature performance enhancements (see http://www.levelten.com/). I realize that the stock tranny can probably handle boost to about 200 HP or so. However, if I go beyond that say, to 250 or 300 HP), there will likely be problems. For a full Level 10 rebuild, their staff assures me that my tranny would be able to handle three times the stock HP max (or 3 x 140 = 420 HP).

Does anyone have any experience with Level 10 mods? They appear to be world renown with many press write-ups; so I should feel pretty save turning my tranny over to their knowledgeable hands although they are talking major dollars - auto tranny rebuild ($3264) and torque converter rebuild ($498). Ouch!!!

Before I go this far and spend that much money, I could take care of the basic mods: header, CAI & exhaust. I also am considering a lighter flywheel and the JWT S3|S4 billet cam set.

In that regard, i am considering the JWT aluminum flywheel ($495) which weighs 13 lbs. this is about 5 lbs less than the stock flywheel. I figure there should be a performance boost of about 2 HP for every pound saved (or 2 x 5 = 10 HP). The JWT header ($450) would provide another 10-15 HP boost, according to their figures.

Many members here seem to recommend the Hotshot CAI ($215). I will assume a boost of at least 10 HP there for argument's sake. I can add the JWT ECU upgrade ($595) and Pop-charger ($159) for another 15 HP boost. The JWT S3|S4 billet cam set ($560) adds another 10-15 HP boost.

JWT claims their cams require their JWT HD valve spring and titanium retainer set ($600) for proper functioning. However, I haven't seen anyone here talk about using the valve springs and titanium retainers. Are they really necessary?

For the exhaust, I see many people saying good things about the Greddy Evo (I haven't check the cost yet). I will assume at least a 10 HP boost there as well.

All told, I'm looking at HP gains of 65-75 to the stock 140 HP max before consideration of any turbo kit. (JWT is still finalizing their production turbo kit for 1991-1999 SR20DE engines.)

Does this seem like a reasonable approach to the dedicated gearheads here? Is there anything I may be overlooking?

Thanks very much in advance for all comments! :sun:

[b-b00gie]

Dont waste your money on a CAI and Headers if you are going turbo. They arent compatible and you are just wasting money.

Dont count on a JWT turbo kit either. There are a few other options already available.

Also, flywheels do not add horsepower.

[jap137]

Okay, my ignorance ois showing. Grant that the flywheels don't actually add power. Hhowever, they allow the engine to rev up faster and generally act perkier.

I'll have to study the existing turbo kits out there more carefully. I guess I've been considering the possibility of avoiding turbos altogether. However, if I invest in the Level 10 tranny overhaul, I may as well invest in a turbo system as well.

[radicalG20]

Before you invest in the Level 10 tranny upgrade, you should just consider swapping in a manual tranny w/LSD. This will be less money and make your G20 much quicker. Also, the lightened flywheel will be more useful on the manual tranny. If you do it right, you should be able to acquire a tranny, clutch, short shifter, and flywheel for less than $2500.


Just my 2c

[jap137]

Thank you very much for your comments, Radical. I still have time to consider a number of options.

However, the Level 10 upgrade is not just something to be sneezed at. It's not just your typical upgrade. Nor do they just refit your AT with state of the art parts. They can provide performance enhancements by finetuning the shift characteristics of your tranny which are comparable to what one can do with a manual transmission.. Stock AT's normally have very conservative lag times between gear shift points that prevents them from being as responsive as MTs. The Level 10 folks can improve the AT's response to give you an AT with MT characteristics. Plus, there's no concern with common MT problems like damaged clutches or broken gears. (See http://www.nissaninfiniticlub.com/me...s/current.htm.)

Finally, Level 10 likes to trumpet their rebuilt trannys as being "bulletproof." By that they mean they can be cared for with minimal reasonable service. It's an impressive boast from a company that has so many satisfied high-profiled customers.

The performance AT is still a very new concept to many people, including myself. I realize many posters here are MT enthusiasts, probably most of you. However, there has been a quiet revolution in MTs, and the day of the conventional MT may very well be numbered. (See http://www.edmunds.com/news/innovati...3/article.html).

I have enjoyed MT autos also. However, it would seem that even conventional MT's will fall to microprocessor control. I have no problem with new technology AS LONG AS IT IMPROVES THE STATUS QUO! Otherwise, it's just another useless gadget.

I realize, Radical, that your comments were designed to save me money. However, I need to look at all the benefits of a Level 10 enhancement and see if it is worth the difference between its cost and that of a new MT tranny set. :licker:

[jap137]

For any of you who had problems getting the first web link I posted, here it is again: http://www.nissaninfiniticlub.com/me...ws/current.htm

[killick]

Originally posted by jap137
Stock AT's normally have very conservative lag times between gear shift points that prevents them from being as responsive as MTs. The Level 10 folks can improve the AT's response to give you an AT with MT characteristics.

Reflect carefully on what you've just said here. With the proper modifications (and enough cash) you can make an automatic perform more like a manual trans. If radicalG20's cost estimate is correct, you could get a real manual for significantly less. Also, with the manual you can enjoy the benefits of the LSD (limited slip differential), which is not available with a built automatic.

If swapping to a manual isn't a viable alternative for you (though the largest impediment is cost ... and the upgrades you're contemplating aren't really more economical), then I guess it makes sense to go for the auto upgrade. However, you're still getting a product that's built to mimic a manual.

But, it's you're penny to spend as you see fit.

[jap137]

I already have LSD on my AT. LSD's are a standard feature of a G20t.

As far as mimicking a MT goes, the Level 10 upgrades are NOT your basic triptronic MT copies. Nor are the new "clutchless" MT's I alluded to in http://www.edmunds.com/news/innovati...3/article.html .

The "clutchless" MT's shift gears with a time lapse of 0.15 seconds - FASTER than any human can with a conventional stick! These new MT's are used by Formula One racers now for their quicker response time.

I was being overly conservative when discussing the Level 10 upgrades earlier when describing them as being on a par with conventional MT's. However, everything I read indicates they make an AT perform BETTER than a conventional MT. From Grassroots Motorsports magazine, see http://www.levelten.com/pdf/grass_08_00_team_lexus.pdf where a transformed Lexus LS 400 struts its stuff against MT-equipped BMW 325's, Audi A4's and Integra Type R's. If an AT-equipped, 3600-pound LS 400 can hold its own against lighter MT-furnished sports cars, what do you think an overhauled GS-300 would do?

Also see http://www.levelten.com/pdf/5.0_tech_98.pdf that describes the swap of a 5-speed MT for a Level 10 AT in a Mustang. Finally, consider the level 10 overhaul of the AT in a twin turbo Supra in http://www.levelten.com/pdf/turbo.pdf where the new super efficient AT made the cars appear to have more horses to their owners.

So you see, I'm not talking about just some cheap copy but a bona fide performance upgrade. I realize that MT purists may not care for any of this, but some of us (like Yours Truly) find little time for messing around with cars (I'm a software engineer and serious amateur photographer, among other things. Since innovation is the rule in my professional world, it is only natural for me to look for it elsewhere, separating the truly useful improvements from the worthless gimmicks.

[poppy_morenito]

Go for it man !!! Don't wait for everyone to nod with apporval. If you do it and works right, you'll be my hero ....

[jap137]

Well, I only wanted to know whether anyone else had actually done a Level 10 overhaul. I have seen testimonials on Level 10's website and elsewhere on the Internet, but no one I can communicate with personally besides the Level 10 staffers.

My real concerns were the mods to boost HP. It seems that a turbo kit would be the way to go, but that will have to wait for later on.

I still am looking into details. (For instance, Level 10 needs to fax me a list of local shops who will strip the tranny and torque converter and ship them to Level 10's facilities in Hamburg, NJ.)

Plus, there are some other personal financial thingies I want to clear up before I do anything at all. However, the overall goal is to end up with a trouble-free auto which can last another ten or fifteen years or so.

[killick]

Originally posted by jap137
However, everything I read indicates they make an AT perform BETTER than a conventional MT.

Please keep in mind that the source of your information is the supplier of the product.

From Grassroots Motorsports magazine, see http://www.levelten.com/pdf/grass_08_00_team_lexus.pdf where a transformed Lexus LS 400 struts its stuff against MT-equipped BMW 325's, Audi A4's and Integra Type R's.

I read the article. I can't help but wonder whether the car would have been better with a MT. Yes, the car's competitive. But I would venture that it's because of the car as a whole package, not specifically because it's an automatic. The very article you reference actually points to some of the deficiencies of the reworked trans compared to a manual (some of which have been since fixed... i.e., the overheating problem). However, one AT-specific issue was:

The system works pretty well, and the drivers haven't had much trouble adjusting to it, although some "between gears" corners can still be a headache. The transmission will still downshift on its own if it senses the need, so when the car is trying to exit a corner in what it feels is too high a gear, it will jump down on its own.

Look. I'm not trying to rain on your parade, or trying to badmouth Level10. I'm just trying to point out that what you're attempting to do is improve the response of an automatic to attain more control of the shift points. i.e., provide manual-like attributes. And it still results in one less gear.

I gotta back out on this one now. Personally, I don't see the point in spending more than the cost of a manual to get something that approximates a manual. BTW, I drive an automatic. Hate it though... but such are the concessions to married life

Anyway man, good luck to you with the mods and stuff. The important thing is that you do what you want to do, regardless of what idiots like myself think. ... And if that kick-a$$ auto-equipped car of yours turns out as well as you hope, then more power to ya.

Hey, maybe you'll make a believer out of an old fart like me.

Cheers.

[G-Forces]

Originally posted by jap137
where the new super efficient AT made the cars appear to have more horses to their owners.

Appearances can be deceiving. I know of one person with an NX2000 that swapped a SR20VE motor and then trubo'd it. He had Level 10 upgrade his AT. His car was featured in SCC about a year ago. You can check out his site at www.gonzonx.com.

A number of people were VERY disappointed in his dyno numbers. His horsepower and 1/4 mile times were significantly lower than a comparable SR20DE manual. Keep in mind he also had this done on a VE. So it should have been a bit higher than the DE even.

AT trannies also have drivability issues on the track as well. Like killick quoted the AT's tendency to change gears at odd times is not a good thing.

I'll stick to gearboxes and leave the torque converters to those 600hp+ dragracers. Don't mistake clutchless gearboxes for automatics either. They use a computer controlled hydrolic clutch and gears. They are also muey, muey, money!

[G22DET]

I think before you go into this huge tranny project, why not get your car up to speed first by dropping in a DET motor or some sort of bolt on kit for the DE? You'll have plenty of fun without having to worry about the tranny and when it's time (or when it's time for you to get more HP) then do the tranny. just my opinion.
btw, forget that JWT flywheel, I have a JUN flywheel that weighs 10.8lbs..got it in stock, $385!!! that's an unheard of price. email me if you are interested.

[poppy_morenito]

Originally posted by G22DET
I think before you go into this huge tranny project, why not get your car up to speed first by dropping in a DET motor or some sort of bolt on kit for the DE? You'll have plenty of fun without having to worry about the tranny and when it's time (or when it's time for you to get more HP) then do the tranny. just my opinion.
btw, forget that JWT flywheel, I have a JUN flywheel that weighs 10.8lbs..got it in stock, $385!!! that's an unheard of price. email me if you are interested.

So If I understand what you are saying, IT IS POSSIBLE to drop DET keeping his existing stock auto tranny .....? I am kind slow becuase this seems like such a reasonable solution I figure ... It must me not understanding it.... It has got to be cheaper that going to LEVEL 10 just to drive around on the street right ?

[jap137]

Originally posted by killick


Look. I'm not trying to rain on your parade, or trying to badmouth Level10. I'm just trying to point out that what you're attempting to do is improve the response of an automatic to attain more control of the shift points. i.e., provide manual-like attributes. And it still results in one less gear.

Anyway man, good luck to you with the mods and stuff. The important thing is that you do what you want to do, regardless of what idiots like myself think. ... And if that kick-a$$ auto-equipped car of yours turns out as well as you hope, then more power to ya.

Hey, maybe you'll make a believer out of an old fart like me.

Cheers.

I don't regard what you are doing as "raining on my parade." However, I have NOT committed myself to anything yet (still fishing), and many of the earlier arguments against my AT overhaul idea were simply not very convincing.

I am not against MT's: I just have to put up with an awful lot of city traffic and that will probably remain the case in my profession (information technology).

I saw the problem you pointed out with the modified Lexus. Keep in mind: I have no hot rodding aspirations at all - I just want to see about getting a more responsive AT.

I realize you were joking, but I wouldn't have posted here if I thought the folks here were idiots.