Hi Folks,

I've been searching all over and I can't find any details on the IPL sway bar stiffness compared to stock.

In fact, all I could find on the IPL suspension at all was 20% stiffer springs in front and 10% stiffer springs in back over S model kit.

Has anyone mentioned the stiffness and have anything to compare to? I'm looking at Hotchkis sway bars and would like a point of reference, particularly in the rear end.

Thanks.

 

Hotchkis are adjustable ipl arent

 

I've never seen anything on the stiffness of the IPL away bars. I've always presumed they are the same as all others. The way to find out for sure is to get the part number for an IPL and non IPL car using the VIN and see if they are the same part number.

Even if they are different, the Hotchkis will still be much stiffer.

 

I'm starting to browse the 370Z forums for suspension questions as there are more members experimenting and modifying their Z's than G's on here. I found this link which has detailed info on sway bars including the Nismo bars which I'm going to assume are the same as the IPL bars. It's at least somewhat of a starting point anyway. It also has measurements for all the other bars on the market.
Sway Bar Diameters - Nissan 370Z Forum

 

I swapped out my IPL sways for hotchkis sways last fall. The hotchkis front bar is non-adjustable (only one hole) and is significantly thicker than the IPL. The rear bar is adjustable (3 holes) and is marginally thicker than the IPL rear bar. I'm using the middle hole on the rear sway bar.

I did not notice much of difference over the IPL sways after the install. It should be noted that I have a convertible so I may need to go with a stiffer setting on the rear bar. That being said, my sense is that the IPL sway bars are either the same as the sport bars or very similar to them.

 

You may need to find your next "weakest" point to really take advantage of the bars. If your tires are sub par, they're going to reach their max before the bars can really shine.

I think I've decided to just leave my stock sways alone and eventually go with coil overs where I can corner weight the car and set it up that way for less understeer. Tire pressure did improve the situation. I'm 33psi front, 34 rear currently with REO50A's. That'll probably change come summer and continuous 90-100+ degree temperatures.

 

I've been searching the 370z boards a fair bit as well, but this one is G specific.

Not that it was that hard, but more because I had assumed it would not be that meaningful, I just measured the sways on the car and have got:

Front: 27mm
Rear: 25.4mm

Comparing that to the NISMO 370z parts and it would appear they are identical. It shouldn't be surprising, but for some reason it is.

The whole reason I'm doing this is because I'm looking at the Hotchkis bar and the advice from the 370z forum is to go as skinny as possible in the back. The Hotchkis website only lists their bar torsion compared to stock and S, no IPL. The comparison to S is only 15% stiffer, so if I can get a comparison of IPL to S I can compare the softest setting to determine if I want to buy just a front bar, or both.

The longer wheelbase on the G will make a difference but I can't find really solid info from folks that track G's to compare rear bar thickness with the advice from the Z crowd.

 

Yeah I just sort of assumed the IPL bars and Nismo bars were the same as well but with the shocks and springs having different valving and rates than the Nismo due to wheelbase and vehicle weight.

I would think, with the car's propensity to understeer, a larger rear bar would be more effective in counteracting that trait. But having a "balanced" set is also probably a good idea if you're making other changes and running track specific rubber that can take advantage of the suspension components. From what I've read, the Hotchkins are a bit overkill for the street-only cars and the rear is adjustable so you could keep it on the softest setting and go from there.

 

I just put an order in for a front bar only, so I'll let you know how it goes.

I autocross the car and I'm prepping it for track work as well, so from all accounts the front bar should be a good upgrade.

 

Any updates looking to ditch my ipl bars if its worth it

 

I got this from hotchkis:
Here is a list of known comparisons:



Front Sway Bar 35mm (Ø1.375") Hollow

Spring Rate: 1970 lbs/in

+230% Stiffer than Stock G37

+205% Stiffer than stock G37S

+230% Stiffer than stock G35S

+205% Stiffer than stock 370Z



Rear Sway Bar 28.5mm (Ø1.125") Hollow 3 Way Adjustable

Spring Rate: 930, 1160, 1490 lbs/in

+140, 205, 290% Stiffer than Stock G37

+15, 40, 85% Stiffer than stock G37S

+70, 110, 170% Stiffer than stock G35S

+70, 110, 170% Stiffer than stock 370Z

 

Rear NISMO is 20% thicker (assume stiffer???) Than 370.

Without measuring we'll never know for sure, but looks like IPL is pretty stiff.

Does anyone have G37S bars they could measure the diameter of, would prove if they're NISMO bars also and could use them as the reference from Hotchkis.

 

Awesome thanks. I should have a caliper measuring tool soon. Ill measure the ipl bars

 

I think Splitter already measured his, post #7, was assuming they were IPL bars, same diameter as the Nismo bars. We don't have a measurement for the S bars yet.

 

O i see gotcha