Hello, I just had a VG30E dyno'd 122 WHP and 14x Torque.Does that sound correct? Nice curve just lowWhat are some numbers you guys have had?

Engine had a fresh rebuild last season. (Not by me, Just picked up this car)Stock internals (rules do not allow mods)TBI manifold with Holley 500CFM 2 barrel on top.Headers to a 2 into 1 collector to open 3 in pipe.I just thought this sounded low? Let me know your thoughts.Thanks,Joe
Modified by bimrtech at 2:43 PM 1/23/2008

I'd say that's probably about right. What transmission are you using on it?

Basing off of the stock numbers of say a 89-94 Maxima VG30E (160 hp, 183 tq) with 20% drivetrain/etc. losses you're looking at 128 whp and 146.4 wtq... with a TBI intake manifold the factory rated power would be less so I'd say those numbers are pretty good basing off of factory rated numbers.

The exhaust may be a little on the big side. What are you revving to? You may play with different exhaust sizes as 3" is usually a bit larger for an NA VG, might have a bit more power right there alone.

Are you unable to modify any of the internals? Cams included? If you can do cams they're said to be one of the best upgrades for an NA VG.

Thanks, car did not seem down on power compaired to others on track, however, dyno numbers looked low. Just wanted to dyno it (baseline) over the winter to see if there are/could be improvements as I just picked up the car.

24% or so loss should be ok considering my oldschool induction. (carb)

If you guys see any way for a possible power improvement, please let me know!!!!


Modified by bimrtech at 10:02 PM 2/12/2008

Quote »8. Valve springs - Aftermarket allowed, stock O.E.M. retainers.[/quote]That right there might allow a bit of increase in performance, so to speak. What are you revving to? I didn't notice any limits on maximum RPM so you may consider getting some JWT valve springs and running the engine up to about 7,000 rpm. JWT does ecu tuning and bumps the rev limiter to 7,000 and, even though the VG doesn't breath all that well up top, it has been proven to make the cars equipped with it faster.

I'd also consider putting on a VG30ET oil pump. Should be legal and offers a bit more volume/flow, which might be a good idea if the engine sees high revs for extended periods of time.

I also didn't see any regulations on actual ignition timing. I'd bump the ignition timing up to squeeze every last bit of power out that you can.

Also consider trying to get that carb as tuned in as possible. If it happens to be putting a bit too much or too little fuel in, I'd do what you can to get the air fuel ratio as good as possible. If your dyno shop has a wide band o2 sensor setup, definitely get that hooked up as fuel tuning can help out quite a bit. The rules do allow carb mods as far as the floats, jets, etc. so I would definitely take that to your advantage and get the fuel tuned as perfect as possible. Try out different jets to attain different fuel ratios and see which one offers the best performance. Do this only after any other modifications to optimize those mods (ignition timing, higher revs, exhaust diameter, etc.)

Since no aluminum flywheels are allowed you may get the stock flywheel machined to reduce as much weight as safely possible. It isn't going to see much stress power and clutch wise so machining shouldn't hurt it.

Couple questions, what kind of race is this for? Seems like it could be pretty fun.

Also, what carb adapter are you using? Just so happen to have another member looking to run a carb on a TBI VG and that adapter would make it much easier.

Thanks, I'll look into you suggestions!

I do have a LM1 from inovative motorsports that I plan on installing on board, however I did not take a recording when dyno'd this time.

I will after the car gets back together and gets back to the dyno. They also have a wide band, I am curious as to how different they may read!

I was not taking it past 6k with present gearing. Others say that they fall on their face at the end of the straight if you do. I did not take it past 6k on the dyno to find out. I will next time. Again, I was not interested in tuning, just getting a baseline.

I don't want to say what series, I think I gave enough away by posting the engine rules! PM me and I will let you know.

Thanks again for your suggestions!I need all the help I can get. These guys spend some $$$

Ahhh... LM1... nice! I think there's a good chance it will probably give you slightly more accurate results than the dyno shop's tail pipe sniffer. I'd definitely get that sucker hooked up and data logging next time you hit the dyno, it is an awesome tuning tool that will definitely help you to get the most out of your fuel tuning.

I think if you get the tuning right you should be able to run it up to 7k RPM without any issues (you'll want the valve springs though as running it that high can cause valve float with the stock ones). It doesn't produce all that much power up there but what has been theorized is that it puts the engine into a much better part of the power band when you shift gears making the car faster overall. I remember two Maxima guys, with nearly equal mods, testing the JWT ECU tune with 7k redline. The Maxima running up to 7k was always faster than the other but when he ran it to only 6k they were pretty well even.

Looked up the series and found it. They definitely keep it nice and even, a driver's race. Pretty neat!

This is a VG30I correct? Not an E. If it were an VG30E I'd say that your are loosing around 20WHP somewhere. A healthy stock NA VG30E puts down 160HP (correct)...but 140WHP, I've seen this time and time again on Z31's.

The VG30I has that thing that looks like a Carberator but is actually a Throttle Body injection. Frankly I don't know why nissan made that....they typically make around the numbers you are getting (Very low HP, but he torque stays pretty much the same)So if it is actually a VG30I you are talking about, I'd say its right on.

What is an I, what is an EAre the heads, cam blocks etc... all the same?Is the only difference between an I and an E the intake?

"that thing that looks like a Carberator but is actually a" yes a carburetor. 500 CFM Holley.

It does have the spec intake, the TBI intake, (carberator looking thing as you state) so is this what makes it a VG30I? If so then I should be on par for power.

You may have brought up some great points if the E has other differences to the I other than the intake! Any info?

As far as I know it was a z motor?? with the sec intake installed.It does have cutouts in the intake gasket/head for injectors????

Thanks!

VG30i had the TBI while the VG30E's all had multi-port fuel injection (later models with sequential fuel injection, early were batch fire).

Other than that everything else is the same. You could potentially cheat a bit using the JDM/Euro VG30ET heads as they have slightly different cams. They have a slightly different duration I believe, which would gain a slight bit of power... but I'd say its probably an illegal mod... though they are technically stock Nissan cams... but to be on the safe side I would stick with tuning.

If you get the tuning rock solid and are able to take the engine to 7k RPM I bet you might just be able to give them hell.

Zdaddy - Technically you are correct. The VG30E's are rated at 155 bhp and above, if I remember correctly. The VG30i is rated at around 145 hp I believe so those numbers are pretty close. The TBI manifold must not flow very well because I don't believe they used different cams in those engines.

bimrtech, an I means TBI, an E means Electronic Fuel Injection.

As far as I know, all VG30E (Naturally Aspirated) are rated 160HP at the crank, VG30ET (Turbo version) is rated at 200HP at the crank. At the wheels, the NA should be putting out 140WHP, while the Turbo should be putting down between 170-180Whp stock.

Yes bimrtech, you have a VG30i. Although I consider the VG a Z engine in general (since thats what it ultimately was designed for) but I would not call a VG30i a Z engine...more like a SUV/truck engine specifically pathfinder/hardbody. I don't know the cam specs on these, and I'm pretty sure the heads are no different than other non-Z heads (slightly smaller intake ports) but I doubt it's what causes such a huge HP drop compared to the E. What is the cause is the I's inabality to mix enough fuel and air to produce high end power. Your TBI just can't deliver the fuel nor the air it needs to make top end power, hence why it cuts out at 122HP. But it's normal so don't worry.

I was told by a pathfinder enthusiast that the VG30i put down 138HP at the flywheel stock. But I guess thats hearsay until I get a Nissan brochure in my hands showing me that info. It's not designed for HP, suv's and trucks only care about that torque so they could haul stuff, or get out of a muddy ditch...making the VG bottom end a perfect candidat

He's actually using the TBI manifold but with a carb on it... so technically its neither the VG30E or VG30i

Some of the VG30E's were rated under 160 hp (I want to say it may have been the 85-88 Maxima). The early VG30E Pathfinder was rated at 153 hp. I believe the 88-89 300ZX was actually rated at 165 hp and the 88-89 300ZX Turbo was rated at 205 (88-89 had the new W-series VG's and the Turbo Z's switched to a smaller T25 turbo for quicker spool).

Where did you hear about non-Z heads having larger ports? I've never heard this before nor have noticed this between my Z and non-Z VG's. Have a link?

Yeah like I said, when it comes to carb'd related, I'm pretty ignorant. I need to learn about them more (only because I should know more about all VG's...) But I do know that stock those TBI's can't do much in terms of HP...Here's an FYI...I haven't confirmed it, and don't quote me yet, but I heard through the grape vine that there were carb'd (non TBI) VG's made...it was called a VG30 (no trailing letter).

About the heads, I became aware of the difference by eyeballing Z31 and non-Z head ports at a local yard. When I have time, I would like to measure the cc's and share that info with everyone. But it doesnt make much difference...perhaps in turbo apps...yes, but NA it might actually improve HP by being slightly narrower (higher intake velocity). There are quite a few big-boys on VGP that make just as much power with these smaller intake ports. I would only use it if I had to though Here's the link VG Powered Community Forum Index -> General Engine Info & Discussion->Different VG SOHC head ports
Modified by Zdaddy at 1:43 PM 1/29/2008

That's very interesting... I've never heard of that before. Definitely going to have to check my heads and remember about that when I go to put together my VG30ETT.

I can not find any information or proof about the difference.When looking for aftermarket replacement heads they list the same for 300 and non 300. when looking at a parts interchange for salvage yards, again there is no difference in heads. when looking at intake manifold gaskets and head gaskets, again no difference.

????

My motor is going back together this week, with the LM1 installed in the Y pipe. and the ???? heads on top. I hope to have it back to the dyno later this week or next weekend at the latest.

I'll keep you posted on the progress.

Oh ya!!!!!!!!! Big discovery!!! Pulled the rear out when repainting the chassis, the left rear brake caliper was stuck make the rear (spooled) a bear to roll. I wonder how much power this cost me?

I'll go out and measure the heads I have tonight. I've never personally noticed a difference but I have a non W-series non Z VG, non W-series Z VG, and W-series non Z VG so I'll find out for sure.

As far as the brakes... I bet you will see a pretty good difference on the dyno. That'll definitely be interesting to see.

Alright... checked the heads of a non-W (84 to 3/87) 300ZX and compared the ports to a W-series non-300ZX VG and they were the same, no noticeable difference (minus simple casting flaws and such).

Hmm. Perhaps all W series had the same size ports as the Z, or It's also possible that not all NON-Z heads have smaller ports. Next time I'm in the yard, I'll take better notes. But this fact is well known amongst versed VG builders.

Are you sure you weren't comparing cobustion chambers? Because those are the same...as well as exhaust ports. It's the intake port that differs, if it differs.

As far as interchange info proof from aftermarket people, and JY people, they are the last places I'd seek out for info.

Checked both the intake and exhaust ports.

I actually just remember that I do have a W-series Z engine (technically its a JDM Gloria engine but I'm pretty sure is the same as the Z, even has "euro" cams which are better than what the Z has) so I'll measure that one hopefully tonight as well.

Alright... did a bit of searching and here is what I found so far:

[quote=""Beck @ Z31P""]Nissan has used several castings for VGs. The number is cast onto the side and it is the first three places after the part code in the part number.

V52 is early Z31 VG30E(T)21V is the W series version of the V52 - same portsV50 is VG20E(T) which has smaller runners to match the smaller intake/plenum and smaller valve seats85E is commonly referred to as "the Maxima head" which later it did come on. It is also on other cars/ trucks, and is the the preferred head for porting because Nissan added some meat that was missing in important places on the V52/21V40V was the newest VG30 head and only available overseas, I don't know much about its dimensions or modifying it. Nissan lists it as a conditional replacement for 21Vs.0W and 1W are VG33 heads and the "ports were revised for emissions" but I haven't seen anyone examine what those changes are.

All of these heads are identical on the top. Springs, rockers, lifters, gaskets, seals, etc are the same. All cams are physically interchangeable. Differences are valve pockets (different size valves), water passages, intake/exhaust passages, head gaskets (different size cylinder bores and water passages), and accessory mounting ears and holes. I'm sure there is more; I'll add to this when I come back across it.[/quote]

Good job! Can you post the link?This info is going right on VGP once it's confirmed. I never really knew which head casting numbers were significant...but now I know what to look for. Put that link up here, don't hog it

Sweet thanks for the info. you guys have been a big help to a newbe on your forum.

It looks like I have Z heads.

Here are a few pics. Motor went together last second today.Well never mind I can not figure out how to upload them?

I don't like to throw engnes together like this, normally take my time clean ever bolt/ piece, however this car is a frame right now and needs to be at VIR the last weekend in Feb.

Hope to have it dyno'd Sat.

AGAIN MANY THANKS for all the info!

I can host the pictures for you or you can get an account at a place like Photobucket.

If you'd like me to host them you can email them to me at mark at machzracing dot com.

Here are the pictures:















High-res versions here:

VG picture 1VG picture 2VG picture 3VG picture 4VG picture 5VG picture 6VG picture 7

Have a few questions about the pictures. Appears you're using a copper head gasket... do you guys have head gasket issues with the standard head gaskets are is it more of just so happened to find some so are using them deal?

Lastly, are those adjustable cam gears? Custom made? I'm actually surprised they allow those.

One more thing I thought of as far as maximizing power. Looking at the crank snout and going by the V52 heads you have the 84 to early 87 VG30E. I would consider going to a 4/87 and up VG30E as they have fully floating wrist pins versus the early VG's press fit pins. Wouldn't be much but you might see slight gains due to reduced friction. On top of that the oil and coolant passages in the block and heads were different (I believe some were added), which might offer better lubrication and cooling for a racing situation. Any legal benefit you can get over the other guys is definitely the way to go in trying to win.

Thanks for hosting the pictures. I will look into building another engine with the newer rods/pistons/block etc.. Great advice.

The cam gears are stock. Just modded to make adjustable.

Noticed a new problem today. We have to run Crane Fireball XR700 ignition to drive the coil, as there is no ECU. However it looked as if there is no advance built into the distributor, cent or vac. So this thing runs at a static timing. Is there a distributor that will ft into the VG that has a centrif. or vac. advance? I have not tried this yet, but I am sure the advance needed above 3k to make this thing have power will make for an engine that is very hard to start if I lock it down at that setting.

What advance do you guys run base/high RPM?

damn my garage looks nasty from those pictures.I need to clean!!!

That is interesting... that must be why they have a hard time running them past 6k rpm... the timing just isn't optimized.

Anyway... I can't think of any dist. available for the VG that has a centrifugal or vacuum advance. I've heard that there was a Nissan truck in the middle east that came with a VG equipped with a standard carb and vacuum advance dist. but that would probably be very hard to find. Supposedly Nissan Motorsports USA offered a vacuum advance dist. for the VG but are said to be no longer available.

I'll keep an eye out for one though as that would definitely help you out.

As far as base timing most of the VG powered cars I've seen were to be set at 15° BTDC. The early turbo Z cars were to 20° and possibly the NA versions but I'm not positive. As far as advance at high rpm... I have no clue at the moment.

Edit:

Here's a timing map from the ECU of an 87 NA 300ZX by Bemis @ Z31P.

http://www.zrelated.com/temp/87NAtimingmap.JPG

Ok, did not make it to the dyno Sat. as my dad came up with a great idea about running advance and within the rules on the dist. (60 yr old man can pull some good ones over the so called experts!!!) Once I get it in place, I will take it. I really want to see what gains this mod will give the engine over running a fixed timing as everyone else does. PM or email me for more info if you want to know the details. I will not post them in public as it should provide decient gains. But... only the dyno can tell. I should have everything ready by Wednesday. Thanks mtcookson for the table!!! That provided some valuable info for setting the base for tuning!

got the LM1 mounted and the bung welded into the exh. I am really curious about its data over the wide band on the dyno. I took my friends SR20 engine that I just built to the dyno Sat. it had a 16 to 1 air fuel ratio. Did no do any more pulls as he needs to buy a adj. fuel psi. regulator, or new ECU to rich. it up. I am really wanting to see if this LM1 is in the same parimeters with the dyno.

Again many thanks to all that have helped me out!

I have some more pics of the engine in the car if mtcookcon wants to be so kind a nd host them for me!

I'm interested to see how you did the advancing, may be able to use it down the road.

Go ahead and email me the pictures and I'll get them posted up.

Ok, sent Prof. mtcookson my pics as he is sooo generous to host for me.

mt, sent you another email with details of the advance setup.

I have to work late tomorrow night so looking at Thursday/Friday for dyno time. Can't wait to see what it does!

VIR is in a week in a half so I got some work to do!

I don't have my computer with me tonight so I'll get them loaded up tomorrow.