Are Micra bodies un-suited for speeds over 125 mph ?

[men-at-arm]

Hi there,

I keep hearing from so-called experts on the Nissan March here in Taiwan -- that modified cars with engine transplants e.g. SR20 series having anywhere from stock power to 300 and 400 hp -- that these cars are just waiting to disintegrate under stresses from high speed top end runs over 125 upwards of almost 150 mph. I'm told factory body welds tend to stress fracture, even when reinforced with added steel and welds and roll cages. That modified high power K11's are just plain un-safe to drive, no matter how bodies are beefed up.

Is this the opinion on this side of the world as well of Micras ?

Thanks in advance~!

 

[Low Rider]

Talk to powerman268 from AUTOBAHN speedworks in Kaohsiung, (you can google him). He is the only person I know of who I would regard as an expert. He's done many CG13DE turbo, GA15DE turbo, SR20DE, SR20DET, SR20VE and SR20VE turbo K11's and, as such, could provide a very accurate opinion based on facts.

 

[men-at-arm]

Thank you~! I know the man . and he wasn't the nay sayer of high power Marches. He has built some beasts down on the southern end. Today, I just spoke to another modifier up here in Northern Taiwan, who is an avid Primera fan. He told me to sell my March and don't bother dropping a DE or VE as I had inquired. He basically believes obviously you can drop any engine that will fit in K11's .. but the chasis is unstable at high speeds and are prone to crack welds.

What do Micra owners in Europe do to beef up your K11 chasis~? (if any)

 

[NeX]

Matt Humphris rallies micras and that puts a lot more stress on them than just driving on a road. generally driving at those speeds is never going to be safe, but as for the car just falling apart, no it wont happen unless its already rusty etc,

i have seen some crazy stuff done with micras including people jumping them, and those are stock micras and they still hold together fine.

do you have any examples where micra spot welds have failed?

 

[solarice]

I dont think youre gonna get the panels peeling off or anything like that haha. Any chassis will wear out eventually, cant comment if a larger engine would speed up the process...though i suppose the argument is the extra weight you'd be carrying would put additional stress on the car.

Are you actually planning on 125mph + ??? If youre not dont worry about it

 

[pollyp]

my 1.3 160bhp turbo went down the castle combe straights at bout 120mph no probs and no panels flying apart lol
next year down nurburgring straight it will be even faster:suspect:
maybe high speed aero stability is more of an issue since its not exactly low drag/lift & sleek

would structural stress from engine torque at high speed be any more than say during initial launch at peak torque?

didn't red bandit have like 400+bhp? without ripping itself apart structurally?

 

[solarice]

Yeah I suppose it'd be launches, gear changes and probably quick directional changes that would add the shock (if you were gonna get any). But then good engine mounts etc would stop the engine flopping about, any additional stress would pass into the chassis though it wouldnt be as aggressive. (imo)

as you say dont think bandit had any probs...his was caged up.

 

[NeX]

i think another thing to think about, is ALL modern cars are spot welded, same size spots, same metal etc, from 1ltr micras to 1000bhp skylines. i can't remember if the veyron is carbon or steel but if its steel it will be spot welded. they are actually pretty strong

 

[joesouthgate]

i think another thing to think about, is ALL modern cars are spot welded, same size spots, same metal etc, from 1ltr micras to 1000bhp skylines. i can't remember if the veyron is carbon or steel but if its steel it will be spot welded. they are actually pretty strong

I'm pretty sure that the 1000bhp skylines would have been seem welded before the conversion, and the veyron is space frame chassis and carbon i think.

 

[NeX]

I'm pretty sure that the 1000bhp skylines would have been seem welded before the conversion, and the veyron is space frame chassis and carbon i think.

true, personally for me i would seam weld any car even if it wasn't welded, but OP was asking if micras could handle the forces even with added steel and roll cages, to which the answer is, of course.

as for the veyron, i think you are right, i looked up a video for the veryon build blog, the chassis is made by a company that normally makes planes, and the chassis is hand welded, aerospace aluminium.

 

[Dave Bull]

The Micra chassis is good for at least 170 mph...PROVEN!!!

 

[K11tj]

as mentioned its not so much the car panels etc, may be they are relating to the stresses put on the cars chassis. I would have thought that in any large engine conversion it would be seem welded ect as a 'norm' to help strenghthen as a just in case scenario along with you would probably fit bigger better brakes, uprated suspension to cope with the extra weight etc etc. Other than that i can not see any issues

 

[superls]

surely all the stress is incurred whilst setting off, launching or cornering, once the car is 'cruising' at say 125 then not much should happen at all