Tunability of rumored R35 engines?

[aco]

The RB26DETT is capable of 600hp with no internal modifications, per Motorex (http://www.skylinegtr.com/about.htm) .

What do you think the capabilities of the rumored engines, VQ and VK, for the new R35 are?

[VQuick]

I don't know about the VQ35DE, but a Maxima owner has turbocharged his VQ30DE and gotten over 350whp at less than 10 psi. Over 400hp at the wheels shouldn't be a problem for the 3.5L version.
The VK45DE would be capable of even more, given it's displacement. There's no way to be sure.

[**DONOTDELETE**]

is the vk45 open deck? why cant Nissan just switch the vq35 to iron block then it SHOULD be able to handle 600 hp. images/icons/confused.gif

[Society_Mike]

well.. seeing as how its a RUMOURED powerplant then its pointless to speculate.
BTW.. its NOT R35.. It is V35 because its losing the great RB series motors.
The V6 is not a desired tuning motor in Japan, in fact most people and most tuners really dislike and distrust it. So I imagine that the US will be able to tune it just as well because of the Japanese not wanting to mess with it.

[aco]

Sorry, let me be more precise. "Rumored" was meant only as to what engine might be used in the next GT-R. The two engines in question, the VQ and the VK already exist. Since these are the two engines most widely talked about for being in the next GT-R, I thought I would ask for speculation on their tunability.

As for R35, I am new to the GT-R and did not realize that the R represented the engine designation.

Another question, why do tuners in Japan "dislike and distrust" V6 engines?

[ 05-20-2002, 10:10 AM: Message edited by: aco ]

[VQuick]

Originally posted by car styling enthusiast:
is the vk45 open deck? why cant Nissan just switch the vq35 to iron block then it SHOULD be able to handle 600 hp. images/icons/confused.gif <font size="2" face="Verdana, Arial[/img]Yes, the VK45DE is open deck. It is based on the VQ-series V6. No, Nissan will not make an iron-block VQ. They'd spend a lot of money making it, you'd end up with an engine very similar to the preexisting VG, and then you lose the weight savings that the GT-R needs so badly.

The VQ should be able to handle around 600hp anyway. With the VQ30DE's higher US-market compression ratio of 10:1, a Maxima owner made almost 400 crank hp with less than 10 pounds of boost. That's more than double the power he had stock(190). The Japanese-market VQs are available turbocharged from the factory with a lower 9:1 compression ratio, which makes them even more receptive to boost.
In it's weakest form, the VQ35DE starts out with at least another 50hp over the VQ30DE in that Maxima I mentioned. With a lower compression ratio and boost, it will own.
The reason a lot of tuners in Japan don't tune with V6s is because most of the cars they like don't come with them. The only one that comes to mind is the Mitsubishi GTO(3000GT), and it's nowhere near as popular as the RX-7s, Supras, and Skyline GT-Rs. But Blitz is already working with the new V35 Skyline in Japan, so we'll see what they come up with. images/icons/smile.gif

[**DONOTDELETE**]

Looks like japan is taking the new nissans with the VQ V6 engine serious:
-3.5 VQ in skyline sedan (272ps)
-3.5 VQ in new elgrand (240ps)
-the tt engine in japan gt-r

They are back!

[VQuick]

I was in another forum after my post here last night. Someone said that Automobile magazine said that the GT-R would be here in coupe and sedan form, both with a V8. I'll believe it when I see it, though.

[_Eric_]

VQuick, that's a bunch of BS. I have a subscription to Automobile mag. and never have they said anything about a GTR sedan.

The have said something of interest in the May '02 issue: "Technical details are sketchy, but American buyers likely will get the hottest engine in the armory, probably a formidable new 4.0-liter V8 delivering more than 400 horsepower."

Even though they are speculating, I sure hope they are right. It's not too far fetched if you think about it. It could obviously be based on the VK. They would drop the compression and slap a big single turbo on there, then shorten the stroke to help it rev more freely. Could you imagine a VK40DET with an 8000-RPM redline? That's what I'm hoping for images/icons/cool.gif

[VQuick]

Yeah, that's the quote I saw at the other site. It'd be really nice if it actually happened, though. I don't know what Nissan will do to get the displacement down to 4L even, though.

The thing is, Nissan should be able to get around 400hp normally aspirated. It already makes 340hp in the Q45, and it's tuned to be really quiet and smooth. I bet there's more power to be found at the expense of more noise. I mean, the GT-R is a sports car. It doesn't need to be quiet, right? images/icons/smile.gif

[paulb]

Nissan may use the VK (VK45/610A) engine from the Indy racing cars. It has 4.5L of displacement and 450hp @ 8100rpm but has only 304 ft-lbs. @ 6750rpm of torque. They might be able to increase that if they add variable valve timing control.

They also have a 3.5L engine (VRH35ADE/612E) producing 650hp @ 10,700 rpm but it runs on methanol.

http://www.nissannews.com/events/infiniti/indy/engine.shtml

[_Eric_]

Great link PaulB, but the VK45/610A used in the Ifniniti Pro Series is 3.5-liters like the VRH35ADE used in the IRL. Only difference is the 610A runs on premium unleaded.

Originally posted by VQuick:
..I don't know what Nissan will do to get the displacement down to 4L even, though.
<font size="2" face="Verdana, Arial[/img]VQuick, the link that PaulB put up shows what I was trying to say in my last post. By shortening the stroke on the VK (the 610A shortens it from 82.77mm to 64.39mm), you accomplish two things. First you decrease the displacement(in this case from 4.5L to 3.5L). Second you make it easier for the engine to rev freer (VK45DE in Q revs to 6900 RPM, the 610A revs to 8200 RPM).

Now if you drop in some lower compression pistons and drop the compression ratio from 10.5:1 to around 9.0:1 or so, you make this engine a little more boost friendly.

They could still make a 4.0L version, just not shorten the stroke so much. The engine could still probably redline around 7500-7700 and you wouldn't lose as much torque.

[ 05-22-2002, 07:49 AM: Message edited by: 2001MaximaAE ]

[VQuick]

Yeah, I guess it would be like how Nissan increased the displacement on the VQ from 3L to 3.5L, although .2L came from a larger bore.
And a 4L V8 would better compete with the rumored Supra replacement. It's supposed to have a 4L V8 as well, so the Lexus 4.3L's displacement would need to be brought back down.
I was at automotiveforums.com and someone else brought up the topic of the VRH35ADE. The big thing about that engine is that it has a magnesium head. Not only is that expensive, but it won't last in the long run. Magnesium is very strong, but also very brittle. Some rally teams used magnesium wheels, and ended up replacing them every 3k miles because they would start cracking. A magnesium cylinder head wouldn't stand up to daily use for very long.

[**DONOTDELETE**]

Nissan already has a pair of VQ turbo engines, the VQ25DET in the JDM Stagea, and the VQ30DET in the Cedric/Gloria. The VQ25DET, on paper at least, already makes equal/more power than the RB26DETT, but that's hard to verify since everybody knows the RB26 made more power than was officially put. However, someone who's driven the Stagea with the 2.5-litre says that it's damned quick, especially for a 4000lb-ish wagon. Which, btw, is based on the current Skyline platform.

The VQ30DET actually makes a little less peak torque than the VQ25DET, but that's because it's been tuned for more low-end torque, and is a lighter-pressure unit (that's better balanced all around according to reports).

Paul Hansen

[_Eric_]

Paul, I'm assuming that by mentioning the turbo VQ models that already exist in Japan, you're implying that it would be easy for Nissan to make the VQ35DETT? Correct me if I'm wrong on this.

First off, let me say I think the VQ series engines are incredible (heck, I own two cars with VQ's, A.E. Max and '01 QX4). They probably are the best V6's in the world. I've driven the new Maxima and Altima with the VQ35 and they are amazing. I think the idea of a VQ35DETT with ~400 HP is a great idea..........in a 350Z super performance model.

My gripe with the VQ35DETT is not whether it's a great engine or not. It's just that when it's applied to the next GTR, I have concerns. There's no doubt in my mind that the VQ35DETT is capable of 400HP out of the box, but here is my concern: is there anything left in the engine beyond this? I seriously question the tunability of this engine. This engine is not exactly known for the strength of it's block or stock internals.

This is how I view GTR heritage (and some might not agree with me), half of the luster of this car is how incredible it comes right out of the box, the other half is the capability and potential this car possesses beyond stock form. If Nissan uses the VQ35DETT in the next GTR, I think they keep the first half of the equation, but lose the second half almost completely.

If the GTR does come to the US and it is priced under $60k USD, I have every intention of buying one. If they do decide to use the VQ35DETT in it, I think I will hesitate before I buy one. The aftermarket would have to show me first that this engine is capable of some serious performance beyond stock trim. This is because I also intend to eventually modify the car once I take ownership. This is why I'm concerned so much with the engine choice by Nissan. But I am confident they will do the GTR lineage proud. Afterall, Ghosn has made it pretty clear that he wants the next GTR to be a showcase for Nissan's top-end technology in the U.S. and Europe.

[aco]

Well said 2001MaximaAE, this is exactly why I posted this message in the first place.
What are others thoughts on the VK engine? I keep reading about weight problems in using a V8, but I think that Nissan can handle that issue with other components in the car. Besides, they have put so much thought into weight distribution in the FM platform for balance that they will no doubt balance the new GT-R as well.

[VQuick]

The VK shouldn't weigh all that much, at least not enough to cause and "problems." The weight is probably very close to that of the RB, and the distribution will still be better, because the V8 is not as long as an I6.

[**DONOTDELETE**]

Originally posted by 2001MaximaAE:
Paul, I'm assuming that by mentioning the turbo VQ models that already exist in Japan, you're implying that it would be easy for Nissan to make the VQ35DETT? Correct me if I'm wrong on this. <font size="2" face="Verdana, Arial[/img]You aren't wrong, and you make good points (in the snippage), but what I was trying to point out was that Nissan has already made nearly the same stock power of the RB26DETT with a single turbo 2.5-litre V6 of the engine series. With an additional litre of engine to develop with, they should be able to make a very capable engine - one that may not have the stratospheric hp levels of the RB26DETT (which was a RB27-28DETT for the actual 650hp+ engines), but may have a greater flexibility than the RB series at the higher hp levels.

I'm reminded of 900hp Supra's that are slower than somebody else's 700hp Supra at a dragstrip. That's an example of somebody that tuned an engine for an overall powerband instead of a narrow peak. I think the overall powerband of a 3.5 VQ with a beefed up block may provide a lot of hidden benefits that won't show up in stat comparisons.

A disreputable source says that a VQ35DET may appear in the 350Z as a light-pressure, big torque application. The GT-R would get a specially strengthened 3.8-litre version of the motor instead...

Paul Hansen

www.apexJapan.com (http://www.apexJapan.com)

[_Eric_]

Thanks for shedding some light on the situation Paul. I totally agree with you that HP figures are not everything. Just look at an S2000, 240HP.....if you rev over 8,000 RPM! It is very important the nature of your engine's powerband, either real peaky or less peak and greater power throughout.

As far as my assumptions with the VQ, they are based on current apps. which are not high-end performance apps. The block, crank, connecting rods, etc. will not hold up to what's necessary in a GTR application. Now if what you say is true about a 3.8L version with a strengthened block and stock internals, then now we are talking a very different breed of VQ, unlike any other VQ in the past.

I still think that for global markets, like the US, it would be very easy to use the VK since they already have a good template to work off of. The VK45/610A (not the VRH35ADE used in IRL) is a perfect engine with only minor mods needed. It already runs on premium unleaded, not methanol, and is for the most part just a destroked VK45DE(I think the Mg head that VQuick brought up is just on the VRH35ADE, not the 610A, but correct me if I'm wrong). I would think this engine also has greater potential over a VQ.

[**DONOTDELETE**]

Got to look at some engine pics of the latest V6-powered JGTC Skyline from when it was being tested. 75kg/m of torque, which works out to about 533ft/lbs. And they only claim some 400-500hp. Yeah, right. images/icons/wink.gif

Converting it to V6 shows some immediate benefits - it's gone from FR to FM-R - front midship rwd. The engine is right behind the front wheels. This is a similar decision to the one Toyota made by putting in the MR2 inline 4 into their JGTC Supra - what they may (not) give up in power, they make up for in car balance.

Paul Hansen

[VQuick]

Yeah, Top Secret did the same thing when they were building a top-speed Supra. The MR2's 3S-GTE made more than enough power, and provided better weight balance.