Modded LX Vs Stock Si?

[Skilz10179]

I'm looking to see what people think on which car will handle better, a lighty modded LX or a stock Si. I am only referring to cornering ability here, i know the Si will be able to enter and leave corners faster due to its engine and brakes. Lets also assume both cars will be fitted with the exact same wheels and tires.

Car 1. Civic LX with HFP suspension and Si front and rear sway bars.

Car 2. Civic Si - 100% stock.

Thoughts?

[Whocares05050]

With what you listed as the setup, the SI, but i feel in an auto-x course the LX will have the advantage due to lighter engine, and no sunroof, and lighter weight car. It would also have to be set-up on a good suspension, and the SI would have to be stock.

[Skilz10179]

Is the HFP suspension for the LX really that mild compared to the stock Si spring/strut combo or is there chassis reinforcements on the Si or other things that give it the edge? I would think that the LX being 250+ lbs lighter would be a considerable advantage.

Good info, keep it coming!

[ImBiginKorea]

You can't really compare them without addressing the power difference, also don't forget the si has an lsd that will change the racing line.

--Korea

[SiLvErLIgHT06]

SI>LX The Si's suspension stock is already sportier/stiffer, plus LSD

[Jardiniboy]

Are they both using the same kind of tires?

[SoCal07Si]

DX FTW!!!

K20 swapped

[habitat]

Lets see, first of all the LX has drum rear brakes which will greatly decrease the corner entry. Second, the fact that the SI has an LSD will greatly effect it's corner exit speed. So in both corner entry and exit, the LX will loose. Third, the SI has a close ratio 6 speed transmission which will greatly increase it's acceleration out of the turn (not to mention the added power). The only thing the LX has going for it is it's lower weight, even the hefty 229lbs will not make up for the lack of braking and LSD.

This is assuming both have the same set of tires.

[Skilz10179]

Thanks for your thoughts although most of you look like you didn't even read my original post.

[Whocares05050]

I read the first post. I think in certain racing conditions the SI will loose.

[RedLineSi]

Si... LSD and sport suspension.

[Sirbelch]

Lx + HFP > Si especially on an auto x course.

The thing about an auto x course is, it’s too slow for the Si to always be in VTEC. 15-60 mph is about the range of speed on an auto x course. The Si will hardly get out of 2nd gear on most auto x courses. So anything below 37 mph, the Si will be off the big cam at which point the power difference between the Lx and Si is negated by the weight difference. Furthermore, the Lx is only down 10 lbs ft of torque to the Si and its torque peak is 1800 rpm lower than the Si. If you do a torque to weight ratio of the Lx to the Si (because torque matters more on the tight confines of an auto x course) the Lx has to pull 20.59 lbs per foot lb of torque, where the Si has to pull 20.76 lbs per foot lb of torque. Also, the Lx can do over 60 in second so it will not require a time wasting up shift to 3rd and down shift back to second.

The Lx + HFP will own in the corners. 229 lbs is a lot of weight to have to change direction. Also, the LX has a lower Cg and better weight distribution than an Si so those will help increase cornering speed.

The LSD in the Si sucks. It does just enough to keep the inside wheel from spinning. Since the Si will be out of VTEC most of the time, there will not be enough power to activate the LSD anyway, so what little advantage it has is negated as well.

Brakes don’t stop a car, tires do. Since both cars will have the same tires, both should have equal braking performance. Regardless of the fact that the Lx has rear drums, it can still lock the tires up. That means that the brakes have more power than the tires can handle. This means that both the Si and Lx will have to do threshold braking in order to keep the tires from locking up and losing time. Once again, the 229 lbs weigh difference will also negate any braking advantage the Si might have.


On a road course however, Si>Lx + HFP. There is not enough of a difference in handling for the Lx to make up the 57 hp difference.


In conclusion, the Lx + HFP will out handle an Si with ease and should beat an Si on an auto x course.

[foch3]

Sirbelch you are awesome. I have learned so much from you and others that I felt I could have answered this question but I am not confident enough yet.

What about the swaybars as well? Wouldn't the SI's thicker bars reduce traction further?

[Sirbelch]

Originally Posted by foch3

Sirbelch you are awesome. I have learned so much from you and others that I felt I could have answered this question but I am not confident enough yet.

What about the swaybars as well? Wouldn't the SI's thicker bars reduce traction further?

From center off, yes the front Si bar reduces traction. If you put an Lx front sway bar on an Si, that would cause more rotation mid corner and more traction on corner exit which would make it faster.

An Lx with HFP + an Si rear sway bar would be a hoot in the twisties.

[ricetastic]

According to a member "highrev1", the LSD actually makes the car handle worse and he is running lx front sways on his Si right now. So with out further adieu, where is highrev1? Basically to sum up his points an LX would handle better than an Si...

[Sirbelch]

Here are Revy's and my explanations of the harm an lsd can do. We are not saying lsd's are all bad and pointless, just saying they can make a car slower if not used/set up properly

Originally Posted by Highrev1

True an LSD can help with corner exit acceleration, but they also tend to add to "throttle induced" understeer on corner exit as well. I should have gone into more detail with my last post sorry.

"For example, Take an open Diff FWD car accelerating out of a turn. The outside tire is heavily loaded (lots of traction) and the inside tire is lightly loaded (very little traction). In this instance the outside front is using 99% of its avalible traction making the car turn. Once the driver starts adding in throttle, thanks to the open diff, the front inside ends up getting most of the power = possible inside wheel spin, the outside gets a small fraction of power, and has to split its avalible traction between cornering and accelerating.. so you get a little more push and not much acceleration.

Add in an LSD... same instance as above, inside lightly loaded, outside heavy load... except in this case, thanks to the LSD, as the driver adds in throttle, the LSD now forces a lot more of the cars power to the tire thats heavliy loaded and not much to the tire thats lightly loaded... SO, now the front outside tire loses a substantial amount of the traction it was using to make the car turn in order to use it for acceleration, and the inside tire doesnt spin... So you've reduced/eliminated inside wheel spin and increased your rate of acceleration out of turns at the cost of increasing the amount of throttle on understeer the car has...

This only gets worse as you increase the effectiveness of the front anti-roll bar. Because the anti-roll bar effectivly increases the load on the outside front and decrease it more on the inside front... which means the car is relying even MORE on that outside front tire to make the car turn, and any loss in cornering traction in favor of acceleration = more push."

SIRBELCH and I went thorugh this Starting on this page CLICK HERE He huffed and he puffed but, oh wrong story....He tired but well you get the point.... as usual this is one of the forgotten threads Alas....I have changed a few around here and to you guys I salute you..

Originally Posted by Sirbelch

In terms of ulitmate grip mid corner, an lsd is bad. It is bad because the outside tire is giving everything it has (traction wise) to keep the car turning. A tire can only provide x amout of grip. So if you are using all of that x amout of grip (which you are in the middle of a corner) and you then tell the tire that it not only has to keep the car turning BUT it also has to start to accelerate the car at the same time, the tire is not going to be a happy camper. The tire is unhappy because it is already doing all it can to turn the car and you just told the LSD to give the outside tire even more work to do. The tire will then quit working causing understeer. Now, on corner exit, when the outside tire isn't using all its x amount of grip to turn the car, the LSD can take advantage of the traction that is left over and put more power to the outside wheel, which in turn accelerates the car more efficiently because the LSD is sending as much power to each tire as it can handle. But there is a very thin line between effective acceleration and understeer.

[Skilz10179]

Great info guys. ^

So does the LX front sway bar and Si rear sway bar used together provide a more neutral grip than using both front and rear Si bars together on a LX? Or will using both Si sway bars on the LX yeild more grip since it has an open diff?

[xxmstajxx]

DX with k20z3 without AC ............Perfect Sleeper.....

Well Call it the " DX CR "

[inyong1988]

si anyday anywhere

[Sirbelch]

Originally Posted by Skilz10179

Great info guys. ^

So does the LX front sway bar and Si rear sway bar used together provide a more neutral grip than using both front and rear Si bars together on a LX? Or will using both Si sway bars on the LX yeild more grip since it has an open diff?

The Lx front and Si rear bar would be best on all.

A thicker sway bar improves turn in by resisting weight transfer. It loads the outside tire quicker so you don't have to wait as long for the body to roll over, push down on the tire, and create the amount of friction needed to get the car pointing in a different direction. The down side of this increase in initial friction (traction) is there is less friction to help accelerate the car coming out of the corner. So you wanna gain a 10th going into the corner or 5 10ths coming out? Your call.