How much power can our chasis take?

What I mean by this is for example, the Z was made from Nissan balanced very well. So it was tuned to work well as a unit.

However, if one goes FI, is there a certain power level that the chasis was not meant to handle?

Another way of putting this is, for instance, the new GT-R to come, C6, or any other car with higher power, the chasis was probably designed well to match the power for fantastic handling. With the Z, it does not have this power, but with FI, the balance is gone.

Should this be a concern? If so, is there a way to strengthen it?

I plan on eventually having appx. 500whp/tq to the wheels and I plan on using it as daily driver and Track events. I here that if you go too much power, you can't handle well and all you have is a drag strip car.

I'm new to all this so I am gathering as much info as possible so I know exactly what I want before I begin to build.

Thanks.

 

You have hit on something that many of us forget about....and you are making a really good point.

As we build these cars for power, we are upsetting the natural chassis and balance of the car. You are very right...which is why a TT Z is such a handful to drive on a road-course...unless you really spend the time and money to dial in the chassis.

For 1/4 mile stuff, the chassis limitation probably plays a lesser role, but on a road course....the drawbacks become really obvious.

With this much power, we should be looking to tuck the largest tire possible into the rear...if a 315 fits back there...I would do that. Upgraded suspension, sways, bushings, and brakes, would also be a good idea.

Like you said, the NIssan engineers deisgned the suspension and chassis for about 300crankHP. Now many of us are pushing 500-600crank HP..and probably 700-800crank HP soon enough.

 

gq,
thanks for responding.

However, even with the upgraded susp, tires, brakes, etc, is that enought to compensate for the chasis itself?

Or maybe the better question would be, how do you define chasis? I define it as the structural backbone or 'Skeleton' of the car. If so, then upgrading the components you mentioned above will only go so far.

Thanks again. Your post was very informative and interesting to read as usual.

 

Well, the good thing about the 350Z chassis is that it is shared by a zillion Nissan cars and trucks. So it's incredibly stiff, and unfortuntaley..very heavy. The weight and stiffness is probably overkill for a 287hp car, but hopefully is within reason for a 500hp car.

I define the chassis to include the suspension, sways, strut bars...etc...all of which will help stiffen and strength the chassis. A roll cage/harness bar will also help stiffen the chassis.

Ask yourself what are the goals for your car. Cruising, canyon run, auto crossing, drag strip? There is a such thing as too much power...depending on your purpose for the car.

 

3200 lbs for a car of this size with an Al motor is certainly on the heavy end. I remember Tom at Lightspeed telling me that Nissan likes to over engineer alot of components to a heavy extent. He's worked on 300ZXs for years and said the underside of the car had an exaggerated amount of supports for just the exhaust. He says its like Nissan likes to stick in supports where ever they can find room. Both the 300 and 350 are pigs for the sized cars they are.

I also remember car magazines like Motortrend and Car N Driver praising the rigitity and stiffness of the 350Z's chassis when it first came out.

Im sure the prevalent use of our FM also helpped increase the weight. Im pretty confident our cars are fine and happy running 500-600 rwhp. If you want a balanced car in terms of lateral performance and stopping power along with the power, then yea you have to upgrade a few other things as well. As far as the chassis bending and flexxing from 500-600 rwhp w/o additional support, like a reinforced roll cage, I doubt it. This isnt a Civic...

 

True enough, our cars are not Civics. But I've wondered what will happen when someone hits the strip for the first time to try out their new 550-HP TT setup. On their first burn-out, will they bend the frame so badly they drive home with one of their front wheels crazily suspended above the pavement? I hope not.

 

My primary goal is handling. I like road coarses (ie track) and canyon runs.

I'm trying to determine what would be a good amount of power that the chasis includ susp (I will define chasis as gq difened it) can handle with room to spare.

I think the worst thing one can do is to have an over-powered car without the chasis to back it up. If anything, I want to error on the handling side.

Overall I feel that the Z is underpowered and that I can get more power and still have great handling to spare. The hard part is finding where the 'optimal' balance for my driving style is.

I guess the answer is more seat time!

 

Well I have been thinking about this same issue lately.

I think 400rwhp is more than enough power for a daily driver without losing too much balance. You could easily achieve that with a APS or Greedy TT kit on a relatively stock Z.

I would also upgrade the suspension to the Tein Flex coilovers with EDFC and the hotchkis swaybars.

 

I dont think you need to worry about the chassis rigidity. My old Z (280ZX) has 600 hp and countless trips to the strip with full slicks, even before it had its cage, and its chassis is just fine...not a single issue to speak of

 

You will not bend this frame. You will snap an axle, motor mount, or driveshaft before you bend the frame....you'll be fine at the 1/4 mile track.

 

no other model uses a z chassis. even the g35 coupe has a different chassis.

 

Given they don't use identical chassis' for Nissans cars but they are based on the same platform. I'm pretty sure that the 350Z, G35, Murano, FX45, and Maxima 3.5 all use very similar chassis'. Not positive about the FX45 but I thought I heard that somewhere. As for the 350Z, G35, Murano, and Maxima 3.5; they all have the same engine basically.

 

They use the same frame chassis.. Maxima, Altima, FX35/45, Murano...etc.

The wheel bases are VERY different, but the main structural frames are all based off the same platform. It's all part of their cost reduction efforts. They take one frame and engine, and adapt it to as many different cars as possible.

 

To make an exmaple of too mcuh power for a chassis. Back in the late 70's I had a BB (427) powered chevy Vega. RWHP was around 500 and during a drag lauches the chassis would flex to the point were my windsheld would pop out. And this was a fully tied chassis. The Z and G uni-bodys are no were near as flexy as that vega 600rwhp should be fine woth these chassis and minimal flex. Hard launches with drag slicks will ellicit the most chassis strain.

 

Hmm.. minor correction.. Maxima, Altima, Murano are all based on one platform. The FX35/45, Z, G, and I *believe* the M are based on the FM platform...

 

you're kinda right. each platform shares the same basic blueprint, but it's not the same chassis. nissan r&d's one basic chassis design and refines it to be as good as possible. then the design is scaled for each individual model. nissan doesn't make 1 million generic frames and cut and paste it for each different model. even the engines that are shared are slightly different. the cars that run the vq35 have different cylinder heads than the truck vq35's.

and actually, the murano, maxima, and altima run the ff-l platform, not the fm that's used on the z, g, and fx.

 

2004 but still relevant. My theory of the 350Z chassis is that it is substantial enough for more powerful engines subject to their weight and it's distribution. Overall weight is very important too, particularly for the OP's purposes weight is relevant to all aspects of a cars performance. But weight and it's control can be neglected if only because most of the off the shelf bolt on improvements are easy to do. If other's real world experience is contrary to the above then please emudicate me.