Solid motor mounts questions before buying highly tuned 300zx

[fr3nzy]

Hello friends,
I am looking to buy a highly tuned 300zx that has dinoed 560 rwhp with Garrett GT2871 Ball bearing turbos, Wiseco pistons and conn-rods and racing crankshaft bearings with around 600 cubic injectors, MAF re-translator with original electronics, 8-pot K-sport brakes, adjustable uni-ball suspension, mishimoto radiator, Spec clutch and flywheel and maybe other parts that I haven't seen already. 95% of the suspension is on polyurethane and ALSO the motor mounts. There is a HARSH vibration inside the car for that matter. The person who showed me the car is one of the most reputable local tuners and he told me that there is no way the car can lower these harshness because the engine parts (turbos, etc.) and chassis parts are very close to each other and twist will incur that will not be wanted.

The question is: Is this normal? Can I actually lower that vibration with other (softer?) bushings without inducing issues like some parts touching when the MONSTER power comes ... I have driven some fast cars but this is phenomenal ... it actually spins its 275/35/18 on 3rd gear and 4 gear every time the boost came and we tested the car only on the lower boost setting 1.1 bar when 1.6 was available but obviously completely unusable without some fresh slicks or additional traction control.

Also is it normal to get boost past 4000 rpm?

The car is LHD and the rear is widened. The body is 6/10 in condition, 110 000 km, very good interior, the engine is strong and the tuning was made not long ago before 2 years and 10000km. Is the price of 8000 EUR good for that specs with some minor flaws like the harshness and small cracks on the front bumper?

Thanks in advance,
Best Regards,
Peter

[nissanfreak12]

Sounds like a fun car, but to answer your question you can run stock mounts on that setup. It doesn't need solid mounts, and even on solid mounts it shouldn't be unbelievably harsh. This is while idle. If you rev it, it should smooth out to a point. It sounds like something is going on, like a injector that may be on its way out or a cylinder misfiring. It even could be as simple as a spark plug having the wrong gaps, causing it the spark to be blown out. I have been in a z that had 540hp at the wheels, it was super smooth, couldn't tell it was running.

As it comes to the boost, yes, turbo cars can boost up to redline. Turbos build pressure at around 3k rpms and go to redline or just before redline. Supercharged cars build boost at a low number like 1200 rpms and stop building at about 2500-3000, dependent on setup and pulley. Mine started to build at about 2500 and I had full boost at 3400, kept that until 6500.

If it were me on buying that car, I would probably pass. I dont know how hard it is to find in your area, but it sounds like there are some underlying issues and if you don't know how to work on cars, these would get very very expensive fast.

[fr3nzy]

Hello,
Thank you for the input. I think too that these solid mounts are not needed at these power rating. How hard is it to change them?

[nissanfreak12]

How mechanically inclined are you? If all you have done is changed oil and little stuff like that, very challenging. If you have replaced an engine before, relatively easy. The mounts are in a very tight area with very little room. It takes me about 4 hours with engine in the car, start to finish, probably could get it done in 2-3 if Im in a hurry. Ive also rebuilt many engines and use to have my ASE certs.

How is the vibration when driving? Does it smooth out?

[fr3nzy]

Yes the vibration does smooth out. I wonder how much hp can be made with these Gt2871 turbos?

[nissanfreak12]

HOnestly, 560 rwhp is quite a lot. If you start going too much more you need to worry about traction and stopping. Its great to have all the hp, but if its breaking down all the time or your fixing it all the time, what fun is that.

Just remember, cheap, fast, reliable. You can only pick two. Even though these cars can be very reliable, they have their limits. I think the stock block can handle 700hp, transmission I think close to the same. Stuff like that you can look at. The turbos, a lot of guys are running them, Im sure they have numbers posted, just gotta search.

[fr3nzy]

Hello again
I have finally bought the car and now I am fixing some little things. Now I wonder what to do with the front intercooler. I want to keep the car streetable and want to put big SMICs, so I could fit back the AC and the front crash structure bar. Is it worth to do this mod and will I limit the performance of the car? The car is LHD.

Picture of the engine bay now:
http://www.q45.org/gallery/gallery3/index.php/IMAG1870

[nissanfreak12]

You can get side mount intercoolers that will not hinder the performance, they are going to be pricey. Best thing youcan do is contact specialty Z and they will guide you in the best direction for where you want to be.

http://www.specialtyz.com/

I have met a few guys running 500+ with side mount intercoolers, some with more.

[fr3nzy]

The people that had tuned the car had told me that they had prepared the car for 900hp. Could I release this potential with the SMICs?

[nissanfreak12]

Call Seb at specialtyz, talk to him. He would be the best one to talk to about the potential.