VG30DETT vs. RB26DETT

[Guest Marshall]

I know these are both popular Nissan engines, and I thought I'd post this. It's not very often that you find a close comparison between 2 engines with similar mods, usually they have different turbos, way different HP outputs, etc. But in this case, I found two pretty good examples to compare.

 

http://www.ooparts-international.co.jp/index/car/listbybrand/pentroof/record/

 

These are 2 engines both tuned by the same company. They equipped both the VG30DETT and the RB26DETT with identical turbos, TD06-20G-L2 8cm.

 

With these identical turbos, the VG30DETT made 746 rwhp @ 6550 rpm, and 865 ft lbs of torque @ 4550 rpm, while the RB26DETT made 759 rwhp @ 7820 rpm, and 543 lbs of torque @ 7000 rpm.

 

First things I noticed were how high the RB had to rev to make its power, and how much of a torque advantage the VG had. The power outputs were very similar, only a 13 hp difference on 700+ hp machines. But the torque output was much different, with the VG having 322 ft-lbs more. So while the RB has 1.7% more power, the VG made 60% more torque, and at a lower, much more streetable RPM.

 

I doubt this will really change anyones mind about which engine to choose, since the hard part is mounting it and from what I heard, the VG30DETT is a royal PITA to get to fit.

 

Just thought I'd share.

[Guest Hubbo]

Was the VG30 an alloy engine? it so, that makes it a real plus!

 

As for fitting being a PITA. Don't a lot of people make new mounts when installing a RB engine anyway? Doesn't seem too different to me.

 

Any way, my 2c

[Aurae10]

Would be nice if someone was making engine mounts for the VG...

 

seems to be easy to get your hands on a nice pair of RB mounts now....just a pain in the ass to get the engine....can't exactly goto the junk yard here in the states

[TomsCoupe]

i prefere the straight 6 over the v6.

[stony]

from my expeirence it is relatively easy to reach the power output of that rb. that VG onthe other hand would need extensive mods to reach that power output. very few people tune on VGs for that reason. It takes alot more money to make the VG perform. Just my 2 cents

[Guest porschephile]

Yeah, the vg30dett is nowhere near as reliable in stock form. Actually, the Vg's power wouldn't be as streetable as the rb's. All that low-end torque would cause you to burnout all over the place! More torque isn't always better. Take a look at a large variety of professional racing engines and you'll see what I mean. Take the Ferrari 355, 911 Gt3, etc etc. They have what some my say is crappy torque, but what they don't realize is this torque is spread over a large amount of the powerband, rather than all low-end, to make for a much more flexible engine on the track. Also, too much torque can upset the balance of the car and make it much harder to control in certain conditions.

[Guest Marshall]

Yeah, the vg30dett is nowhere near as reliable in stock form. Actually, the Vg's power wouldn't be as streetable as the rb's. All that low-end torque would cause you to burnout all over the place! More torque isn't always better. Take a look at a large variety of professional racing engines and you'll see what I mean. Take the Ferrari 355, 911 Gt3, etc etc. They have what some my say is crappy torque, but what they don't realize is this torque is spread over a large amount of the powerband, rather than all low-end, to make for a much more flexible engine on the track. Also, too much torque can upset the balance of the car and make it much harder to control in certain conditions.

 

The VG is just as reliable in stock form. The RB is easier to work on which makes it more popular for tuners in Japan. Unlike the Supra's I6, the RB will not handle as much HP in stock form. But regardless of if the J-spec boyracers want to admit it or not, the VG can produce more power. There are quite a few drag racing cars which use the VG engines, while the RB's are rarer. Car I saw at Englishtown had a VG30DETT making 1,200+ rwhp, stock crank.

 

The VG doesn't make all the power low end, it is also spread throughout the powerband. Remember, you can control the amount of torque as long as your car still has a gas pedal That extra torque is just available if you want to use it, while if you don't have that extra torque, you have no choice, you can't use it. It has slightly more displacement, so it is less laggy and has more torque with the same turbos.

 

And by the way, I have not seen a hybridZ with a RB come close to matching the performance of the VG powered cars. VG30DETT powered 280Z mentioned on another board is running low 10's with a nice wide powerband.

 

The RB is a nice engine, but it's "rare J-Specness" give it much of its mystique in the US.

[Guest Marshall]

from my expeirence it is relatively easy to reach the power output of that rb. that VG onthe other hand would need extensive mods to reach that power output. very few people tune on VGs for that reason. It takes alot more money to make the VG perform. Just my 2 cents

 

The VG and the RB would need the same mods to reach that power output. Both would need larger injectors, an upgraded ECU program, larger turbos, different cams. While both engines can, and have put numbers such as those down with stock internals, it would be a bit irresponsible to spend that much money on an engine and not cough up the extra $2000 on pistons and rods. I don't think it takes more money to make the VG perform, for instance your RB makes 392 rwhp with upgraded fuel and intercoolers; I've seen VG's put out over 400 rwhp with stock engine/injectors/intercoolers with the boost turned up.

 

BTW, your car looks nice.

[stony]

I've seen VG's put out over 400 rwhp with stock engine/injectors/intercoolers with the boost turned up.

 

Thanks for the compliment... but i have to rasie the BS flag on that one. the stock turbos will not support 400RWHP. to get 430 rwhp you need upgrade injectors/intercoolers and turbos (2530s) set at 18 PSI. The intake and heads on the VG need extensive work to flow alot of power.

 

When you say stock crank on a 1200HP VG that is a stock crank that has been worked over and balanced. and i guarentee that it is a hi dollar motor as the rb would be at that level.

 

 

Anyways im partial to rb motors as chevy guys are to the SBC and there is nothing anyone can do to convince me different the the VG is a better, easier to mod motor then the RB. the only other turboi motor i would ever consider wrenching on is the 2JZ or the GN turbo V-6

[AKWIKZ]

Both are notoriously good engines, but here are a few things to think about. The fastest drag Z's in Japan are RB powered. There is no question that the VG is stout, but look around at the high h.p. Z32's here in the U.S. and very few have hit 1000 hp. I've seen quite a few in the 600-700 range, but I can't for the life of me remember a streetable 1000 hp VG powered car. I've heard that the exhaust manifolds have been a limiting factor in this, and I'm sure people will get around it. On the other hand, there are many Skylines running around with over 1000 hp. HKS and Greddy each have at least a couple. And at least half of those are streetable. Just a few months ago Turbo Magazine had a "bolt on build up" as they put it. They took a U.S. legal R33 and with somple bolt ons made 700hp at the wheels. This was on a stock block. I've heard a few people talk about how much stronger the Supra engine is. While it's a great motor, my money would be on the RB in a fair fight. How many other production engines can you think of that have been handicapped in organized racing in order to make it "fair" for the competition. Group A racing, befor it banned the Skyline all together, limited boost and put restrictors on the RB26 in hopes of leveling the playing field. Unsuccessfully I might add. Sorry for the long post. Thanks

Brian

[Guest Marshall]

I've seen VG's put out over 400 rwhp with stock engine/injectors/intercoolers with the boost turned up.

 

Thanks for the compliment... but i have to rasie the BS flag on that one. the stock turbos will not support 400RWHP. to get 430 rwhp you need upgrade injectors/intercoolers and turbos (2530s) set at 18 PSI. The intake and heads on the VG need extensive work to flow alot of power.

 

No need to raise the BS flag- I'll show you one as proof.

 

http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=831511&words=400%3a%3arwhp

 

411 rwhp, 452 rw torque.

 

-Stock engine

-Stock turbos

-Stock injectors

 

On an engine with 120,000 miles.

 

He's not the only one who has done it, there have been others. Ash, for instance, put down 413 hp to the wheels on stock turbos.

 

The 2530 turbos are much, much larger turbos- one guy posted his dyno of 597 rwhp with them.

[Guest Hubbo]

I would just like to point out the latest edition of Speed (013: June-july 04) as it has a nice write up on the skyline GTR in the GT500 and the current Z33 GT500 contender.

 

Anyway... basically it points out that the 2002 and 2003 spec skyline GTR GT500 car actually ran a VQ30dett motor.

With the Z33 using a VQ engine they mentioned that if a new GTR were to be released it could have a VQ based engine. Hmmm.....

 

Look like the RB engine is long dead, in favour of the VQ. Surely there must be some rationality in there insanity? ... I mean come on, a VQ powered GTR?

[AKWIKZ]

As impressive as that graph is, I have to question it. At 411 rwhp, that would translate to about 500 at the crank. Now, when you take that number and put in into an injector sizing table you come out with this: (approx)

BSFC of a turbo engine should be .6 or .7, normal injector cycle is 80%. When you put these in, you come out with a requirement of 650cc injectors. Even if you push the envelope to 100% cycle and drop the BSFC down to .5 you come up with 440cc.

I'm pretty sure that the VG30dett has smaller injectors than the RB26 does, somewhere around 370cc or so. The GT-R and Pulsar GTi-R both have 444cc injectors from the factory that are the largest Nissan equipped any production car with.

Unless he is running all the way on the ragged edge, not to mention way lean, I kind of doubt that the motor is all stock.

Brian

[Guest Marshall]

As impressive as that graph is' date=' I have to question it. At 411 rwhp, that would translate to about 500 at the crank. Now, when you take that number and put in into an injector sizing table you come out with this: (approx)

BSFC of a turbo engine should be .6 or .7, normal injector cycle is 80%. When you put these in, you come out with a requirement of 650cc injectors. Even if you push the envelope to 100% cycle and drop the BSFC down to .5 you come up with 440cc.

I'm pretty sure that the VG30dett has smaller injectors than the RB26 does, somewhere around 370cc or so. The GT-R and Pulsar GTi-R both have 444cc injectors from the factory that are the largest Nissan equipped any production car with.

Unless he is running all the way on the ragged edge, not to mention way lean, I kind of doubt that the motor is all stock.

Brian[/quote']

 

He was pushing it, but it WAS on a stock engine. The post is accurate, and as I claimed, 400 rwhp is possible on stock turbos.

 

On a stock 120,000 mile engine.

[Guest Marshall]

Also, as I pointed out, that is on everything stock, including injectors. In reply to the original poster who said that the stock turbos cannot put out 400 rwhp, the stock turbos have put out more HP with larger injectors.

 

The main problem isn't the turbos/injectors capability themselves, the main problem is the difficulty working on the car. For many mods, such as turbo replacement, you have to pull the engine to get access. And most people feel they might as well build the engine up while it's out of the car. If it were easy to replace the turbo without pulling the engine, you'd see more people pushing big power on stock internals.

 

A couple people push the limits of stock items mainly to prove a point, but that's rare, since it's not the cheapest or easiest thing to do. But one guy ran a 11.6 @ 123 mph on stock turbos (with larger injectors) in his TTZ. Remember that the TTZ is 3475 lbs.

[Mack]

yeah, I Id have to agree with those out there that dont like the VG engine cause its soooo fircken hard to work on! lol!!!! but, they are built, like any other nissan engine. and they can pound out the ponies. large, tractable torque bands as well. as far as the head-flow problem, simple solution to that would be to get a set of VG30DET heads from a mid to late 90's Cima. I saw a pic of a VG30DET head next to a VG30DETT head, and I must say the DET head looked like it flowed A LOT more on the intake side than the DETT head. It woudl be interesting to see more built VG's. Ive heard rumors of the VG30ET's putting down in excess of 800rwhp. there is a guy in puerto rico or something with a 1st gen 300zx doing crazy things in the 7's I think. anyway, enough rambling, Im out! lol

[stagefumer11]

I would just like to point out the latest edition of Speed (013: June-july 04) as it has a nice write up on the skyline GTR in the GT500 and the current Z33 GT500 contender.

 

Anyway... basically it points out that the 2002 and 2003 spec skyline GTR GT500 car actually ran a VQ30dett motor.

With the Z33 using a VQ engine they mentioned that if a new GTR were to be released it could have a VQ based engine. Hmmm.....

 

Look like the RB engine is long dead' date=' in favour of the VQ. Surely there must be some rationality in there insanity? ... I mean come on, a VQ powered GTR?[/quote']

 

 

the rb has been scraped for only one resion. due to japans new emssion laws they cannot make it meet the new standards in emmissions. the vq's can tho.

[Guest Marshall]

I would just like to point out the latest edition of Speed (013: June-july 04) as it has a nice write up on the skyline GTR in the GT500 and the current Z33 GT500 contender.

 

Anyway... basically it points out that the 2002 and 2003 spec skyline GTR GT500 car actually ran a VQ30dett motor.

With the Z33 using a VQ engine they mentioned that if a new GTR were to be released it could have a VQ based engine. Hmmm.....

 

Look like the RB engine is long dead' date=' in favour of the VQ. Surely there must be some rationality in there insanity? ... I mean come on, a VQ powered GTR?[/quote']

 

 

the rb has been scraped for only one resion. due to japans new emssion laws they cannot make it meet the new standards in emmissions. the vq's can tho.

 

I'm sure cost cutting measures were also a major reason. They could have spent the money to make the RB produce less emissions, but why? Nissan is trying to cut costs by using as few original parts across their product lines as possible. The VQ is their main drivetrain platform that they're trying to standardize on, with the Maxima, Altima, 350Z, Pathfinder, G35, I35, FX35, Murano, and Quest using it.

 

Same goes with the VG30DETT, that's gone also along with the RB26DETT. Now the successors to both the Z and the Skyline will use VQ engines.

[mtcookson]

As impressive as that graph is' date=' I have to question it. At 411 rwhp, that would translate to about 500 at the crank. Now, when you take that number and put in into an injector sizing table you come out with this: (approx)

BSFC of a turbo engine should be .6 or .7, normal injector cycle is 80%. When you put these in, you come out with a requirement of 650cc injectors. Even if you push the envelope to 100% cycle and drop the BSFC down to .5 you come up with 440cc.

I'm pretty sure that the VG30dett has smaller injectors than the RB26 does, somewhere around 370cc or so. The GT-R and Pulsar GTi-R both have 444cc injectors from the factory that are the largest Nissan equipped any production car with.

Unless he is running all the way on the ragged edge, not to mention way lean, I kind of doubt that the motor is all stock.

Brian[/quote']

 

Not to start a fight or whatever, but one thing you forgot in your calculation was fuel pressure. With an increase in fuel pressure you can get more out of smaller injectors. 4th gen Maxima guys do it all of the time with the Vortech FMU. I know some of them are running incredible amounts of pressure through the injectors but they are still getting some incredible power out of them.