lsd vs atts again - Honda Prelude Forum

accel · 11-03-2007, 02:31 PM

ok. I know the technical difference between these. My question is - what's the difference to the actual driver at the actual race? Pros vs Cons.

I have a base 5th gen model (open diff) and tried ATTS at an autox once. Wasn't too impressed though... It's most likely a matter of habit, but prelude's nose was sliding into a turn under the power and made me countersteer as I already positioned the wheel next to a cone myself and didn't expect any extra assistance.

I have an LSD (Quaife) sitting in my garage and I wonder what the actual difference would be at an autox. I pretty much will appreciate acceleration out of turn part, but what does LSD change in turns? Entry, exit? Under power? Etc.

Also, anyone could recomend a reliable place for install in SF BaY Area?

LowFlyin' · 11-03-2007, 05:16 PM

There is a huge difference between a SH and base at an autoX. I'm surprised that you weren't impressed... It is still a FWD car, so you can't go diving into the corners and hoping your overworked tires are going to pull you out. Where the SH shines is on the apex and exit when you have properly setup the corner. You can get on the throttle much sooner than a base, a often times sooner than a RWD car would.

Off the line, the LSD is going to have better traction, but around the corners...ATTS, hands down.

Mr Blue · 11-03-2007, 08:41 PM

WOW... I agree with Lowflyins statement about the ATTS... Other drivers of front wheel drives who rode with me during an autoX race were AMAZED with the way the ATTS controlled and pulled the car through the corners. I run a Quafie LSD (Quafie pulls great but....) now but i miss my ATTS. I am actually rebuilding my SH block (Mahle 9:1 Pistons, with eagle i-beam rods; to handle 15psi of boost) and ATTS tranny back in the 99 lude for the next race season... It will handle up to 300hp before she slipps... i didnt have any ATTS slippage issues with 10psi of boost.

Mr Blue · 11-03-2007, 08:48 PM

Hey Lowflyin... I am dropping a JDM H22a into a 91 CRX this winter... Damm those CRXs handle great... I blew up my F/I Lude half way though the season and had to drive my sons N/A 91 (Converted) JDM d15 Vtec for the second half... Dammm that biTTCCHH handles good... a little more power and i will be the fastest on the track instead of the second... of corse its a Super charged B18 CRX that is beating me!!!

LowFlyin' · 11-03-2007, 08:54 PM

I've got a B16B in mine. I haven't driven the car with this engine, yet. It has been down since I spun a bearing in the B16A that was in it before. Should be a completely different car when I get back on the ground, though. Along with the engine, I've added a Quaife LSD, Progress Time Attack Coilovers, and the interior is stripped of everything but the dash and seats. Can't wait for next season!

accel · 11-03-2007, 11:45 PM

Quote:

Originally Posted by Mr Blue

I run a Quafie LSD (Quafie pulls great but....) now but i miss my ATTS.

Well, that's what I need to understand. Could you try to define the difference between these two systems? I'm not talking about technical aspects , just about the difference this makes at the course. ATTS, I cannot have one. But I can have Quaife. And there should be reason why ITR has LSD but not ATTS.

Jacques · 11-04-2007, 12:49 AM

Before you can answer what LSD basically does in corners, you'll also need to keep in mind there's two different kinds of LSD. Viscous LSD's are basically speed-based, in which it will adjust when speed increases. Though that may be fine with regular driving where adjustments are minute, in a racing situation it won't aid you as quickly, especially in situations where speed might not be a factor (ie: slow, steady state corners). The Integra Type R, as well as the Quaife, uses a helical LSD, which is torque-actuated, shifting torque to the outer wheel in cornering, and giving equal power when going on the straight line. The execution of the helical in a corner is fairly smooth, almost to the point of being unnoticeable (to me anyways)...but it works well.

ATTS is also torque-actuated, hence the acronym's definition..."Active Torque Transfer System". Though a helical has an advantage in a straight line in terms of power delivery (ATTS doesn't do much, if at all, in a straight line), the system works at its fullest around corners, sending torque to the outer wheel (approx. 80%). Unlike the helical LSD, when driven hard, not to mention mechanical, the ATTS puts its torque out rather abruptly, and does this electronically. It takes some adjusting in driving style if you've never driven an SH hard before, but if done right, you can get into throttle even before you reach the apex and power through all the way to the exit. People that have ridden along, and some that have driven mine, were amazed how balanced it felt, with almost no understeer (a little bit of oversteer, party due to my suspension setup), rotated very much like a RWD car, and how easy throttle response is around corners.

po0p · 11-27-2007, 10:26 PM

I love atts. The only thing you need on top of it, is a stiffer suspension and wider stickier tires. You'll have a lot of fun with the car.

lude4lifeh22 · 11-28-2007, 06:44 AM

Quote:

Originally Posted by Jacques

Before you can answer what LSD basically does in corners, you'll also need to keep in mind there's two different kinds of LSD. Viscous LSD's are basically speed-based, in which it will adjust when speed increases. Though that may be fine with regular driving where adjustments are minute, in a racing situation it won't aid you as quickly, especially in situations where speed might not be a factor (ie: slow, steady state corners). The Integra Type R, as well as the Quaife, uses a helical LSD, which is torque-actuated, shifting torque to the outer wheel in cornering, and giving equal power when going on the straight line. The execution of the helical in a corner is fairly smooth, almost to the point of being unnoticeable (to me anyways)...but it works well.

ATTS is also torque-actuated, hence the acronym's definition..."Active Torque Transfer System". Though a helical has an advantage in a straight line in terms of power delivery (ATTS doesn't do much, if at all, in a straight line), the system works at its fullest around corners, sending torque to the outer wheel (approx. 80%). Unlike the helical LSD, when driven hard, not to mention mechanical, the ATTS puts its torque out rather abruptly, and does this electronically. It takes some adjusting in driving style if you've never driven an SH hard before, but if done right, you can get into throttle even before you reach the apex and power through all the way to the exit. People that have ridden along, and some that have driven mine, were amazed how balanced it felt, with almost no understeer (a little bit of oversteer, party due to my suspension setup), rotated very much like a RWD car, and how easy throttle response is around corners.

Well said James

When I was on the track, one of the first things I noticed was how early I could hit the gas in a turn.

I found that most of the time when I began to lose the rear end, just accelerating would take care of it. This is usually the case when taking a turn, but with the ATTS, not only did it save the rear end from cutting lose, but the power being transferred to the outer wheel, would cause my turn to become tighter and tighter. It throws you off at first, but then you begin to figure out how to use it.

In long turns that are often hard to negotiate because you are trying to find the apex, I found that with the ATTS I could just ride the inside of the line. While others behind me were trying to just stay on the track at that speed. I could probably go a lot faster if I took the corner like I should using the apex.

Quote:

Originally Posted by po0p

I love atts. The only thing you need on top of it, is a stiffer suspension and wider stickier tires. You'll have a lot of fun with the car.

BIG +1

Jacques · 11-28-2007, 01:24 PM

Quote:

Originally Posted by po0p

I love atts. The only thing you need on top of it, is a stiffer suspension and wider stickier tires. You'll have a lot of fun with the car.

OMG, a po0p sighting!

I put in some wider tires late this summer, going from 205/50/15 to 225/50/15 (both were/are Kumho Ecsta V710 r compounds). On the autocross course, lateral grip was even better than before. I'd like to take it out on the roadcourses this spring and see how much better the grip will be. Suspension may be different as well by then, but like my current setup, it'll be stiff.

vwong · 11-30-2007, 09:51 AM

Quote:

Originally Posted by Jacques

OMG, a po0p sighting!

No kidding!!! Nice to see po0p posting again!!!

Back on topic, I really missed the ATTS. My ATTS hasn't been working since I put the prototype EMS on. When I first went on the track without ATTS, it took a bit of time for me to get used to because the inside front wheel spinned like crazy, therefore the car pushed on corner exits. I'm ok with it now, but I still wish that my ATTS could work. Oh well, I sacrificed ATTS for a better tuned motor. I'll be in the market for a Base tranny swap hopefully beginning of next year, and I'll probably install an LSD at the same time.

boymeetsfence · 12-12-2007, 09:20 PM

Guys I can say or sure that this thread has made me proud to be an SH owner

A bit off topic, but I do need a bit of help figuring out my next mod for power, any other proud SH owner feel like giving me a tip or two? Maybe a PM?

lude4lifeh22 · 12-13-2007, 02:31 AM

Quote:

Originally Posted by boymeetsfence

Guys I can say or sure that this thread has made me proud to be an SH owner

A bit off topic, but I do need a bit of help figuring out my next mod for power, any other proud SH owner feel like giving me a tip or two? Maybe a PM?

There are plenty of threads on ways to make power with bolt ons. SH vs Base is not that different when it comes to making more power (besides the fact that ATTS has a power limit).

Do a search. If nothing, make a new topic. This thread is about ATTS vs LSD. Not power gains.

ludehawk · 12-13-2007, 09:57 PM

you can delete your own posts still? ya, I suggest doing that...

boymeetsfence · 12-13-2007, 11:56 PM

and why is that?

Solid · 12-14-2007, 12:47 AM

Quote:

Originally Posted by boymeetsfence

and why is that?

I think what he means that you are ranting about how everyone is snobby about new people on the board, but they were just trying to maintain order by letting you know that talking about power mods is not on topic with this thread.

lude4lifeh22 · 12-14-2007, 06:00 AM

Quote:

Originally Posted by Solid

I think what he means that you are ranting about how everyone is snobby about new people on the board, but they were just trying to maintain order by letting you know that talking about power mods is not on topic with this thread.

Thank you. I was not being snobby.

DR · 12-14-2007, 02:05 PM

I got rid of the ATTS for several reasons but unless you competitively road race I don't think it is a wise move. My reasons were:
1. My car was way over the minimum weight in the class I was running and the net loss (taking off ATTS, installing Quaife) lost me ~35 pounds. 35 pounds is nothing unless you are competitively racing.
2. There is no good way to use an aftermarket final drive with the ATTS and the class I ran required 16" wheels. All the tires that would fit the 16" wheels made the gearing too tall which made the acceleration poor. 15" wheels and tires are shorter which make the gearing shorter which make the acceleration much better.
3. A good programmable ECU like the S300 gains about a few hp over a well tuned VAFC. Again a few hp don't mean much until you get very competitive.

On the positive side I felt the ATTS system was smoother than a LSD and like others have said, I could get on the throttle sooner. In sharp corners I often could get the rear to rotate by getting on the throttle instead of getting off of it. It always put a big smile on my face when I felt that back end coming around and I was on the throttle, just like a RWD car.

lude4lifeh22 · 12-14-2007, 06:07 PM

Quote:

Originally Posted by DR

I got rid of the ATTS for several reasons but unless you competitively road race I don't think it is a wise move. My reasons were:
1. My car was way over the minimum weight in the class I was running and the net loss (taking off ATTS, installing Quaife) lost me ~35 pounds. 35 pounds is nothing unless you are competitively racing.
2. There is no good way to use an aftermarket final drive with the ATTS and the class I ran required 16" wheels. All the tires that would fit the 16" wheels made the gearing too tall which made the acceleration poor. 15" wheels and tires are shorter which make the gearing shorter which make the acceleration much better.
3. A good programmable ECU like the S300 gains about a few hp over a well tuned VAFC. Again a few hp don't mean much until you get very competitive.

On the positive side I felt the ATTS system was smoother than a LSD and like others have said, I could get on the throttle sooner. In sharp corners I often could get the rear to rotate by getting on the throttle instead of getting off of it. It always put a big smile on my face when I felt that back end coming around and I was on the throttle, just like a RWD car.

Nicely said David. I always felt bad because I hear so many competitive racers removing the ATTS and wondered if it was insufficient. But what you said makes perfect sense and shows that the ATTS is a creditable device when it comes to handling and track advantage.

boymeetsfence · 12-16-2007, 11:33 AM

Quote:

Originally Posted by Solid

I think what he means that you are ranting about how everyone is snobby about new people on the board, but they were just trying to maintain order by letting you know that talking about power mods is not on topic with this thread.

Fine, my apologies... however I did ask for someone to contact me outside this thread about power for the SH because I knew it wasn't on topic. I also hate when specific topics turn into off-topic chats.