Twin Turbo VH45 in a boat

[elwesso]

This thread was also seen in infiniti general a few months ago but ill repost...zerothread?id=149003

LINK: http://www.dynologic.com.au/vi...w.wmv

[Mettler]

Dude....

That's just absolutely bad *** !!!

Astonishing @! I want it !!!

[Ezekial]

I have spoken to the engine builder / tuner of this speedboat at nizpro.

Very VERY cool guy to talk to.

I discussed my setup with him and he informed me of what is and isnt done to that race boat engine.

It is essentially a STANDARD engine. Just rebuilt. It was using factory ignitors and factory coils. He made mention of changing to HKS items. I think perhaps just the ignitors. Because he said they were suffering from severe heat from the high mount turbo's. ("you could weld with the spark from the hks items") It uses a Motec ecu and standard nissan head gaskets. The engine produces close to 1000 hp.

The engine has lasted numerous runs now.

Simon commented on how unbelievable the engines were!! And said i hadnt even started to push it when i said i wanted roughly 800 flywheel hp.

[Mettler]

When you say standard but rebuilt, do you think he meant standard including stock rods, pistons, etc ?

If that's the case... I may well be interested in supercharging/TT'ing mine afterall ! I was just concerned about exploding the engine after talking to a guy from NZ who went through five motors getting the TT setup to work.

[Ezekial]

When you say standard but rebuilt, do you think he meant standard including stock rods, pistons, etc ?

If that's the case... I may well be interested in supercharging/TT'ing mine afterall ! I was just concerned about exploding the engine after talking to a guy from NZ who went through five motors getting the TT setup to work.

and i'll bet this is the reason why it blew up -------> DODGY ECU SETUP OR TUNE(R)!!!!

Spend the money on a competant aftermarket ecu and you can say goodbye to alot of the inherant problems.

The standard pistons are fantastic! Flat top, no dominant hot spots prone to detonation. Moly coated i believe as well. The top ringland is decent size as well!

The standard conrods are huge! oil squirters from factory also.

I cant say for sure but from memory he said "likewise" when i said i was using factory conrods and pistons. We only differed in head gaskets and I think i am going to run factory head gaskets again after talking to him.

Very cool guy!

[Mettler]

That's just plain awesome, best I can describe it as. SUCH GOOD GEAR !!!! It'd cost over $10k to build an old muscle engine to this standard... absolutely kickarse!!! I'm definitely going to have to work this engine up for big HP now !!

I wasn't planning on going aftermarket with my ECU, but rather, hacking it with a romulator and a pocket programmer, and mapping it out myself. Just as much control as an aftermarket, shouldn't need to pay the extra $$$ for a motec or anything.

[Ezekial]

i'm not familiar with all that stuff so i wont comment on it. i cant see why it wouldnt work provided the ecu can recognise boost accurately.

Motec is very expensive in USA isnt it. I guess we are lucky as it is only $3000 AUD or there abouts over here for the m800.

There are other cheaper options also. Autronic, Microtech, etc

Microtech would be a very cheap and EASY option for anyone with a Q45 as you could let the standard ecu run everything else in the car and the Microtech can run injectors and coils and VVT. Under $1000 AUD or $1100 with a hand controller that can display accurate water temp, air temp, boost, vacuum, RPM, etc

Just an idea anyway. Alot less hassle once its installed. You can tune yourself on the fly as your driving around.

I wouldnt bother getting the crank modified, nitrided or anything like that. I only did it because the engine was apart.

If you are going to do it. Make sure the engine is up to scratch. A simple compression test for the rings. And I personally would inspect the bearings but thats up to you. Then spend the money on GOOD turbochargers and GOOD injectors.

Injectors1. SARD or2. NISMO or3. 2nd hand cleaned and flowed 550 cc injectors. I run SARD 850cc

Turbo's2 x Garrett 500ish hp GT3076R turbo's with 0.8* rear housings would be awesome. 500 hp turbo on a 2.25 litre isnt pushing it at all. Especially if you're only running 15psi or so. (I'm thinking of a Q45 here)

Then get a cheap 600x300 Intercooler for $175 AUD and become friends with a guy who can weld.

The rest is easy!

There is so much information available on this forum and i know many people would be willing to help you.

[Mettler]

Thanks Ezekial, I could swear you're trying to talk me into it I'm from NZ by the way.

I don't think the Microtech support the VVT (VTC according to wiring diagram?)... I sent them some enquiries and the ECU they recommended to me is the LTX12, which I think costs closer to $1500 AUD.

Romulator, Pocket Programmer, some spare chips & socket etc will only be around NZD$650, and provide more control and flexibility than an aftermarket ECU.

Don't forget, the factory Nissan ECU is a 32-bit unit which already controls every single aspect of the engine management. The only thing it lacks is the ability to change any of the settings. With the romulator and pocket programmer however, you effectively have a computer that's more powerful than any aftermarket 16-bit units, even MOTEC, and programmable in realtime too !

About the only thing it doesn't do by default is boost/turbo settings, but my friend who's an electrician says you can set up an input & output for such settings to run through the factory EEPROM too.

I'm not planning on pulling the motor down or anything, can't be bothered with the hassle as it's a huge job, and this motor's done very low kms.

As for injectors, I'd probably go for NISMO... but not unless I actually decide to run boost

Turbs, I'd probably be inclined to run a couple of factory RB25DET turbos, rebuilt though with better compressor & turbine wheels etc.

As for welding, haha already got mates with the gear & the hookups, and metals are dirt cheap for me as I'm the purchasing manager for a manufacturing company.

As long as you guys don't get sick of me picking your brains for info... I may well end up doing it :p

[sijoko]

The standard pistons are fantastic! Flat top, no dominant hot spots prone to detonation. Moly coated i believe as well. The top ringland is decent size as well!

The standard conrods are huge! oil squirters from factory also.

So that VH45 in the Nizpro boat is running stock pistons and factory head gaskets? Wow! That sounds too good to be true.

Didn't you say a while back that the compression ratio didn't come out to the stock 10.2:1 as per your measurements? I thought I remembered a number that was in the mid 9s.

Is that right? Maybe that explains why the VH can survive under boost.

Also, what do you think of the rods? I have never found any documentation that says the VH rods are forged but they must be because Nissan overbuilt this engine, just like the SR20 and VG30. I am planning on getting an engine to do a rebuild and was wondering what were the weak links.

- Siju

[Ezekial]

Thanks Ezekial, I could swear you're trying to talk me into it I'm from NZ by the way.

I don't think the Microtech support the VVT (VTC according to wiring diagram?)... I sent them some enquiries and the ECU they recommended to me is the LTX12, which I think costs closer to $1500 AUD.

they most definately do support VVT. triggered via rpm. yeah that is retail price

Quote »Romulator, Pocket Programmer, some spare chips & socket etc will only be around NZD$650, and provide more control and flexibility than an aftermarket ECU.

Don't forget, the factory Nissan ECU is a 32-bit unit which already controls every single aspect of the engine management. The only thing it lacks is the ability to change any of the settings. With the romulator and pocket programmer however, you effectively have a computer that's more powerful than any aftermarket 16-bit units, even MOTEC, and programmable in realtime too ![/quote]Yes i know it can be done but aftermarket is soo easy

Quote »I'm not planning on pulling the motor down or anything, can't be bothered with the hassle as it's a huge job, and this motor's done very low kms.[/quote]Hmmmm ok thats up to you.

Quote »As for injectors, I'd probably go for NISMO... but not unless I actually decide to run boost [/quote]Whats the point then?

Quote »Turbs, I'd probably be inclined to run a couple of factory RB25DET turbos, rebuilt though with better compressor & turbine wheels etc.[/quote]Well that'd be a cheap option.

Quote »As for welding, haha already got mates with the gear & the hookups, and metals are dirt cheap for me as I'm the purchasing manager for a manufacturing company.[/quote]it sounds like you've convinced yourself. Which is what i like to hear

Quote »As long as you guys don't get sick of me picking your brains for info... I may well end up doing it :p[/quote]i can handle it. i'm sure john can too. And then there are very VERY helpful people like wes that make everything alot easier also

[Ezekial]

So that VH45 in the Nizpro boat is running stock pistons and factory head gaskets? Wow! That sounds too good to be true.

like i said its not as if the standard pistons are crowned or have any prominant hot spots so with good tuning there is no reason why they woudlnt survive. as for the head gaskets if you are worried, ACL in australia make triple layer metal head gaskets for them for under $100 AUD / bank. available in a few different thicknesses.

Quote »Didn't you say a while back that the compression ratio didn't come out to the stock 10.2:1 as per your measurements? I thought I remembered a number that was in the mid 9s. Is that right? Maybe that explains why the VH can survive under boost.[/quote]Yes i have the figures at home but the 10.2 was a slight exaggeration.

Also, the key is the 68 degrees ABDC closing inlet cam.

Take 1JZGTE for example. We all know they can take 20psi no problems unopened. In fact 2 good friends are pushing upwards of 26psi unopened on 98RON pump fuel. About 93 or less in US standards.Static compression ratio of 8.5:1. However factor in the inlet cam closing at 41 degrees ABDC and you end up with VH45 dynamic compression ratio and 1JZGTE less than 0.1 apart

Hence why the standard camshafts are not great for NA applications.

Quote »Also, what do you think of the rods? I have never found any documentation that says the VH rods are forged but they must be because Nissan overbuilt this engine, just like the SR20 and VG30. I am planning on getting an engine to do a rebuild and was wondering what were the weak links.

- Siju[/quote]The conrods appear bigger than SR20 conrods. Really the let down is the valvetrain. Lack of inner valve springs and the HLA's. Both of which limit the rpm. Weak point ... well someone said the rings but i'll see if i have any problems

[sijoko]

.

Yes i have the figures at home but the 10.2 was a slight exaggeration.

Also, the key is the 68 degrees ABDC closing inlet cam.

I know that the Japanese usually measure the trapped or corrected compression ratios on their engines, but from everything that I have read, the corrected is always less than the static compression ratio.

Now, maybe the VTC will cause the engine to act like a 10.2:1 ratio at certain points and that could be reason for the higher than static ratio. Could the reason for the 68 degrees ABDC be due to the valve overlap with the VTC setup?

Also, you mentioned the pistons as having oil squirters. According to the Lubrication Circuit diagram in the service manual, oil is sprayed on to the pistons after it leaves the connecting rods. Do you think that this setup does a decent job of cooling the pistons?

-Siju

[Ezekial]

I know that the Japanese usually measure the trapped or corrected compression ratios on their engines, but from everything that I have read, the corrected is always less than the static compression ratio.

Now, maybe the VTC will cause the engine to act like a 10.2:1 ratio at certain points and that could be reason for the higher than static ratio. Could the reason for the 68 degrees ABDC be due to the valve overlap with the VTC setup?

ok so yes it closes at 48 and switches to 68 around 1500 rpm or so and then will switch back to 48 after peak torque or there abouts. I believe Q45tech has written something about this.

Static is always 10.2 because that has nothing to do with cam timing. Yes as inlet cam timing changes this increases and decreases the dynamic compression

Quote »Also, you mentioned the pistons as having oil squirters. According to the Lubrication Circuit diagram in the service manual, oil is sprayed on to the pistons after it leaves the connecting rods. Do you think that this setup does a decent job of cooling the pistons?

-Siju[/quote]I think its a great idea!! And i cant see why it wont do the job. Many engines dont have piston squirters at all

[Bart]

Nizpro have a forum also if your interested in visiting it?When Simon talks about engine tuning he heavily emphisises on the tuning capability of Motec, and how criticle tuning is to keep an engine together, the Motec has many auxilary functions for various controls, stepper motor, solenoids etc.I believe the VH45 in that boat has stock internals, although he is building a few VH's of different stages of modification and HP, if i remember rightlyhe is aiming well over 1000hp.

[maxnix]

Yeah, but one thing to remember it is quite one thing to build a turbo engine that is at WOT most of the time vs. one on the street that cannot suffer lag at any rpm/load and relies on water to air cooling.

[Mettler]

Just out of interest, what fuel is that thing running ?

[Ezekial]

Yeah, but one thing to remember it is quite one thing to build a turbo engine that is at WOT most of the time vs. one on the street that cannot suffer lag at any rpm/load and relies on water to air cooling.

surely a street car suffers less hardship than a race boat engine that is in excess of 7500 rpm for minutes on end?

[Bart]

800+hp 7500rpm for 40+minutes, not too shabby.Certainly an advantage would be limitless amounts of water to keep this baby cool, preventing heat saturation at the intake and engine block/heads.

[elwesso]

I gotta say if you have a good definiition file you can tune the stock ECU just as good as motec. Just make your boost mapping MAF based... The stock MAF and TB are good to 700-800 HP (90mm)... if you wanted to run an MAP based thign then obviously youd have to go aftermarket or find a way to tune the ECU as such...

If you wanted more HP you coudl always set up a twin TB setup and just simply double the MAF voltage inside the ECU.. youll only run one MAF but you can double the voltage in the ECU.....

You can also fairly easily change the ECU parameters to use the NISMO injectors. Stock 370s are good to about 450HP, and the 555s should be good for a lot more... Good news is they should plug right into the VH rail!

Im glad oyu talked to Simon about the engine, he didnt want to share info to me. Sounds like its almost a stock motor.

Woudlnt you say though that running high boost on the VH45 with the valvetrain as stock is pretty good (maybe with stiffer springs).....

[elwesso]

surely a street car suffers less hardship than a race boat engine that is in excess of 7500 rpm for minutes on end?

In the cooling department, no way. A boat can bring in fresh cool water to cool the engine whereas a stock motor has to do it by "conventional" means... Even by using water/water heat exchanger (which is what a lot of salt water boats use to prevent corrosion, especially on aluminum engines) youll be cooling with 70-80* WATER, nad not 80* AIR... If your running fresh water, you can pump fresh water right in.

Plus in his setup as hes moving through the water at a high rate of speed there is some air cooling going on.

[Mettler]

What fuel is the race boat running ?!?!?

[Bart]

Dont know what fuel its running, perhaps the Nizpro forum will say???

[elwesso]

I doubt hes running something special, proabbly just normal high octane..... But i cant say for sure.

[Ezekial]

wes ... i cant see the valvetrain causing a problem with running high boost. its the rpm that will be killed. like i have said i am just using GTiR SR20DET inner valve springs with the standard outer valve springs

[Dano]

That thing is flat out awesome. The sound is so sweet and look at the thing, it's gorgeous!

-Dan

[Mettler]

wes ... i cant see the valvetrain causing a problem with running high boost. its the rpm that will be killed. like i have said i am just using GTiR SR20DET inner valve springs with the standard outer valve springs

Wait a sec, does the factory VH41/45 have inner valve springs at all ?

What benefits are to be had by installing these ? Do they have a higher spring rate and thus additional prevention of valvebounce ?

Can the additional force cause other problems, like the valves hitting the seats harder, increasing the wear ? Or wearing our the roller rockers quicker ?

If not, then I see no reason why I shouldn't immediately get some !

[elwesso]

Do they have a higher spring rate and thus additional prevention of valvebounce ?

Yeah... Thats it.. However I wouldnt install them on a N/A motor..

[Ezekial]

Wait a sec, does the factory VH41/45 have inner valve springs at all ?

What benefits are to be had by installing these ? Do they have a higher spring rate and thus additional prevention of valvebounce ?

Can the additional force cause other problems, like the valves hitting the seats harder, increasing the wear ? Or wearing our the roller rockers quicker ?

If not, then I see no reason why I shouldn't immediately get some !

no the VH45 does not have inner valve springs at all

the increase in pressure from using inner springs (dampers) is generally only slight but just enough to make a few differences here and there

what benefits? well you can make your own mind up but some that come to mind are: increased rpm, reduce or eliminate valve bounce/float, reduce or eliminate valve spring surge

um have a quick read of this

http://www.cranecams.com/?show=newsLetters&no=153

Quote »The most common means of ?resonant point? control is the use of flat-wound damper springs. These provide the same effect that occurs when a tuning fork is struck and then placed against a solid object (the noise vibrations stop). The damper springs stop the ?shivering? of the coil springs.[/quote]

[Mettler]

Interesting read, thanks. I'll probably install the inner valves at some point or another.

In what other ways is the SR20 engine similar to the VH motor ? I've heard more and more about the two engines, enough now to believe they're very similar in architecture and potentially share a number of parts.

[Ezekial]

Interesting read, thanks. I'll probably install the inner valves at some point or another.

In what other ways is the SR20 engine similar to the VH motor ? I've heard more and more about the two engines, enough now to believe they're very similar in architecture and potentially share a number of parts.

the head studs and inner valve springs are all i have come across so far. GTiR SR20DET though ... not the normal run of the mill sr20 engine