I am new at the forum but from what I have read, the most boost anyone is running is like 9 PSI. I also read that some people with auto trannies that were running on 6 and 7 PSI blew their trannies. My question is, does anybody know how much PSI our engines can really take? Can the VQ take upwards of around 30 PSI or more? If so, would it absolutely have to be a 5-speed. I have heard good things about strong built auto trannies and I have heard bad. If the VQ can take that much boost, is there anything that would have to be done to strengthen the 5-speed other than new clutch. And also could somebody please tell me once and for all, would it be better to go with strong built auto or 5-speed conv. I figure our engines can take that much boost since there are Civics taking upwards of 20-25 PSI, but I don't know for sure. If anybody could tell me anything about any of these things it would really help me out. Thanks.

 

a vq + 30psi = either 1 billion pieces of metal scatered about or about 1000hp

 

no stock civic engine is running 25psi. maybe a cryotreated purpose built decked, sleeved block, with a forged crank, rods, pistons, arp head bolts and some serious intercooling. Why 30 when 15 would be more than traction would allow anyway. Really a vq30de is a stout engine but it is 10:1cr and was not intended to be boosted in the first place.

 

you dont need to push 30+psi through a vq30de to make good power. 10-12psi is plenty for a street driven maxima.

 

Civics were not meant to be boosted either, all you have to do is spend money.

 

 

bro 9 psi is plenty and 12 is PLENTY.
forced induction on a VQ is MUCH different than on a b16 or another 4 cylinder. I myself would not waste my time boosting an auto, but that is biased because i already have a stick. There are plenty of people boosting autos and pulling decent times.

 

because of the advanced timing and 10:1 compression ratio, the car cannot handle that much boost.

 

I didn't exactly mean stock. I meant with built internals. I already knew that it wouldn't do that. I don't really know of any engine besides one dezined for racing only that would handle that kind of boost. I mean with strong internals.

 

if you build it right...anything is possible. but why would you need 30psi on the street..ever heard of traction? and good luck finding proper engine management

 

ohh I thought this was about tire pressure...

 

Go tell that to a turbo diesel...you can run higher compression engines under forced induction, and it has and will continue to be done successfully. The problem comes from the almost exact tolerances and perfect tuning required to actually keep the car running. Higer CR engines with boost give you the best of both worlds...

 

30 psi ...WOW!!! if a Max could be built to handle that...

which would be far from requiring JUST the engine to handle it.......

you would prolly drop $50k for that **** to work. but if it did....I see 800+hp and 9s!!!! hehe.

 

YOu can run 30 no problem...





Be sure to take pics .












Or just go ahead and get to building...your looking at all custom work and probly 35-45 grand to build it up right...but when it's done.....boy that front wheel drive is gonna suck.

 

I don't think any of the current aftermarket engine components would handle 30psi from a decent sized turbo. Would be kind of cool though.

But yeah, if you went to 30psi, you'd need a whole new transmission setup, axles, and all associated drivetrain hardware just to keep it together.

My friend has a race Supra that runs 35 psi on a T-88 turbo that's been modified to a 91. Weird watching the boost gauge just keep climbing on the dyno.

 

I don't see the point honestly. Is 400fwhp at like 12 or 13psi not enough? With fwd you'd be spinning your tires through 4th. If you found the right place to do it, I think a very well built auto would be able to handle the power better than a build 5spd. And again, if the car is being built purely for drag racing, an auto is what would give you the most consistent times.

 

auto is consistent, but consistent doesn't mean faster IMO as far as FWD import draggers go, manual tranny > auto tranny 99.9% of the time.

 

Hey kinda off track but does anyone know or have an educated guess on how much HP the manual tranny in the Max can take. I mean ive never heard of any manual tranny taking a dump, just auto slushboxs unless no one is sharing the info

 

I agree but once you get in the 9 sec range or quicker manuals lose time. Wonder why Titan switched from a 6 spd....
Anyway I run 40 psi...in my tires

 

wow thats sick!!!!!!!!

too much!!

 

Can we say 3.4 stroker kit soon

 

I run 50 psi in my tires..

 

Not a VALID comparison between a diesel and gas engine.

Diesels and detonation work together, so you can keep cranking the boost until the head bolts/gasket give. Gasoline engines aren't tolerant of much detonation ESPECIALLY when you get into the higher hp/liter range.

Definitely not the same engine design and can't be compared.

 

Soon? It's already available at your local junkyard.

Just throw the VQ35 crank/rods into your VQ30 for a killer NA 11:1 CR beast.

 

Deisel engine dont' have spark plugs either. The fuel ignites under the high compression.

But on another note, yeah high compresion engines can be boosted, the m5 has a supercharger kit out for it that keeps the 11.5:1 compression ratio. Just gotta have really nice parts and alot of planing.


NIsann dont have that.

 

I was just guessing 30 PSI because there are daily driven Supras CRX's and hatchback Civics running around that and they are hitting 10's daily driven. Thats what I'm trying to do. Not be able to hang with the Supras and Civic Hatches but beat them. There aren't enough Nissans in the world of street racing. It's not every day that you see a Skyline cruising downd the high way, whereas its common to see a lot of Supras and RX-7's. They are known as the big boys in the U.S for street racing. Occassionally you will see a 240SX with an SR20DET but not as often as a Supra. The VQ30 is very tunable and our cars weigh less than a Supra and not much more than a 240SX. I'm just trying to stand behind Nissan because our cars are very underated. It seems we take to much of a backseat to Honda's, and with just about the same engine as the 300ZX I figure that Maximas can be a force to be reckoned with. We even weigh less than 300's depending on what year Max you have. There is a White sleeper Max where I live and it killed a friend of mines Mustang that runs 13.0's. It had turbo for sure but other than that I don't know. I'm just trying to make people see what our cars can do.

 

THe reason you see them, is because they have a TON MASSIVE TONS of parts available for build ups. You can do it to a maxima, but you can't buy it off the self. You would have to go custom.

 

sad but tru.

 

Actually the reason why I used that comparison is solely for the fact that high compression engines can be blown...I wasn't really comparing the methods of the overall combustion process.

 

high compression engines are the best engines to add forced induction to simply because the more naturally aspirated power you start out with the more boosted power you can have. the only problem is detonation. top fuel dragsters and all the professional draggers use the highest compression allowable. the reason they get away with it is because of the fuels they use. wether it be methanol, nitromethane, ect. they get away with it. just you wont be driving on the street with them. also the higher the compression ratio the more energy the exhaust pulses will have to better spool a turbocharger.

also you compare the max against rx-7's supra's and 240's. hmmmm small difference between those and the max. its called real wheel drive versus front wheel drive. the reason they are dominant is because of the traction advantage. you just dont have a chance on the street against them unless you have a lot more exp and mods or they just suck.

as far as 30psi is concerned... supras can run 30psi because their engines are the epitome of perfection. impossible to blow, powerful as hell, and last forever. the only problem they have is that in the upper reaces of pressure they can blow the stock oil pan gasket. thats about it. the hondas can do it from the pure amount of cheap aftermarket parts available off the shelf. i garuntee that no honda is running 30psi on the stock block or bottom end. the honda engines are just like the toyota 4age's. the heads are beautiful works of art that will outflow and outperform almost anything out there, but the blocks arent worth crap. the 4age block will hold a little over 380 hp before it lets go and the honda blocks are about the same. but it is just easy and cheap it is to just buy a new racing block or sleeve the stock block. thats how hondas get away with it. that and they dont weigh sh*t

if the maxima and civic were to trade places then everyone here would be talking about what sleeves they were using instead. its just to do what the hondas do will cost a lot more money. and besides the beautiful VQ30 doesnt need 30psi to kick a hondas a**. also if the max and civic were to trade places most of us wouldnt be here because most of us dont wanna be seen in something that everybody else is doing. god i hate hondas.

 

[QUOTE=Superdude4agze][QUOTE]

 

I agree on alot of what Superdude4agze is saying, except that the 2JZ is the epitome of perfection. Because Japan's top 3 sports cars that are allowed and were sent over here are the 300ZX, the Supra, and the RX-7. Out of all of those three they all make a twin-turbo model. The 300ZX outperforms both of the other two models and the VG30 is not that much different from the VQ30. Don't get me wrong it is different in alot of ways and better, but its also is very similar. Keeping in mind that it is rear wheel drive, which does give a big advantage traction wise, but front wheel drive cars can go just as fast as rear wheel drive cars with the right things done to them. Other wise nobody would be racing Hondas. And by the way, I am sick of Hondas as well.

 

in what aspects??

 

Performance, but I dont know about handling. I'll have check about stock curb weight

 

I retract my previous statements about the 300 outperforming the Supra in performance. They are about equal. Both cars weigh 3400 to 3600 LBS, but the difference is that the PSI is only at 9 pounds on the TT 300 whereas the Supra is running 12 PSI and is making 320hp. This does not include the years after 98 when they stopped bringing it to the U.S. Just U.S marketed ones. Either way you can get about the same car only for about 5-8 thousand dollars less. It still proves my point about the VG30 being very tunable and well built, because the 300ZX can handle upwards of 500 or more bhp stock.

 

the Supra can and has been known to hold the same if not more power than that. VG30DETT is still a good motor but far from a God send and NO remotely close relation to the VQ like you said earlier...so still there isn't much that proves one better than the other.

 

I've seen Supras go way more than 500 bhp on stock internals. 300Z's have good motors, no denying that. A couple of my friends drive heavily modded ones so I know what they can be made to do. But several of my friends drive even faster Supras so I know what they can do. Out of the 300ZX, RX7, and Supra, I think everyone considered the 300ZX the worst performer, I don't think people thought it was better than the Supra or RX7.

The VG30DETT is a good motor, the 2JZ is a better motor. And the VG isn't really related to the VQ at all other than they're both V6's and are both 3.0L.

And why on earth would you say that a FWD car is just as fast as a RWD car? Even with all the right things done to a FWD car, it will be slower than a similarly equipped RWD car. Yeah, there are 8 second FWD Hondas, but look into how much work goes into it. Then go look at say a 8 second RWD V8 and see how little work (relatively) went into that.

 

There are 2JZs putting more than 800 to the ground on stock internals. I know of one putting 760 to the ground on stock internals in my own small town. As far as stock straight line performance. A stock 6spd supra is good for about 13.4 @ 104 stock, whereas I wouldn't put money on a 300Z doing better than 13.7 @ 101... the supra is the faster car from the factory and easier to get power out of because of the extreme overengineering that went into the 2JZ-GTE. The VG30DETT is a good motor, but it is NOT overengineered to the extent that to 2JZ is.