Improving the VG30E

[260DET]

What I've learnt(?) so far is that the stronger VG30DETT crank and rods will fit while the basic single cam engine itself was improved in several ways from April '87. The oil pump of the VG30ET has 25% more capacity.

 

Good cams are available and the heads can be ported but thats about all I've heard about the top end. I'm looking at using a turbocharged VG30 in a project, mainly because its a simple engine, is light and compact. Around 400 rwhp would be the aim.

 

Anyone have any idea as to what head mods would be required? Rockers? Lifters? Plenum?

 

Am also looking at the VQ engine but for 400rwhp don't believe twin cams and four valves are necessary. The bulkier heads would also be a space problem.

 

I've found plenty of passing references to hot single cam VG's but nothing much in detail.

 

EDIT para 1

[tfreer85]

I don't belief the VG30DETT came out till '90-91 ish. They are easily modded to 400rwhp. What is the vehicle that you are looking to put the engine into? If its an 280 or below Z then there is a lot of mods required to do so, just have to do a search for it.

As for the VG30ET it has similar mods but not as many. This website http://zacksz.homestead.com/Scottscar.html should tell you pretty most if not all of the mods that need to take place. If you want 400rwhp and just want to keep to head work, i think you'd be very hard pressed to get those numbers. You could do a complete Port and Polish on the heads, intake manifold, do a custom exhaust manifold, larger turbo, ecu, etc. which would help you get to those numbers. But some of those are limited to what the application you are fitting the engine into. Hope I helped.

Tyson

[260DET]

Thanks Tyson, para 1 has been edited to clarify its meaning.

 

Had a look at that site, interesting, not the detail I'm after unfortunately

[OK85ZX]

You don't need a stronger crank to get 400hp, just go with the stock crank. As for 400hp out of a vg30et... a gutted intake or a pathfinder intake will work best, good cams, valve springs (schneider) a hybrid turbo, intercooler, and fuel+some way to control it

[mtcookson]

yeah, you don't need to change the crank over however using the TTZ rods can be beneficial. they're forged unlike the stock rods in the VG30E. if you do that though you'll need to get pistons made that uses the floating pin used in the TTZ rods and pistons. you can't, however, use the exact TTZ pistons. the combustion chambers of the VG30E heads are a bit bigger than the VG30DE(TT) heads so the compression ratio would be quite a bit lower.

 

400 whp shouldn't be too hard to do. as said above the basic mods would be cams, valve springs, turbo, intercooler, fuel, pathfinder intake would definitely be a good mod as it is supposed to be the best flowing intake of any VG30E(T) engine. a custom intake might work a bit better but the pathy intake would be the next best thing. a quality port and polish would be good as well. might port the exhaust manifolds but the stock VG30ET manifolds have been proven to flow enough for at least 400 whp.

 

you'll also need a good ecu setup (jwt, romulator, zemulator if the 3rd gen maxima ecu is used, etc. etc.) the zemulator would probably be the easiest for a standalone type setup. jwt would be the easiest in that its pretty much plug and play but is a bit expensive and would take a while to receive. romulator is a little bit harder to use compared to the zem but is very affordable and works very well.

 

also, i'd personally run a 9:1 compression ratio setup instead of 8.5:1 as it keeps good low end and spools the turbo quite fast but that's really just personal preference. 8.5:1 would work just fine.

 

hope this helps a bit.

[260DET]

Thanks, that does help. So roller rockers are not required? What max RPM do you reckon with the forged rods? Going to use a sequential injection MoTec ECU, they are a lot cheaper here than in the US I believe

[mtcookson]

the stock rockers work just fine (and i don't believe there are any aftermarket upgrades anyways). with some upgraded valvesprings (http://www.jimwolftechnology.com) you should be able to rev the engine up to 7,000 rpm safely. 6,000 rpm is the stock redline and with stock valve springs the valves start floating shortly after 7k but to be safe you want to upgrade the valve springs. they're pretty low cost so its not a bad purchase.

 

the rods come from an engine that spins to 7k rpm so they'd be fine.

 

ferrea makes valves for these engines as well. they have stock sizes and 1 mm oversized valves. some say the oversized ones aren't necessary and there isn't too much material to machine from the heads for them but i know some people have upgraded to them. there aren't any dyno numbers to show whether or not they're worth it though. a flow bench test would be the best but not sure if anyone would be willing to do one. in the end, the valves probably aren't worth upgrading until you start trying to push some major amounts of power.

 

for pistons some Z31 guys recommend BRC Performance (http://www.brcperformance.com/) as they have high quality products at good prices. i'd tell them that you need pistons for a 88-89 VG30E(T) as they had the floating wrist pins. (or you can just tell them that you need the pistons setup for floating wrist pins). the forged VG30DE(TT) rods and pistons use floating wrist pins.

[260DET]

Thanks again mtc, whats your opinion of the single cam VG30, compared with the twin cam VG's and the VQ? Modified to get 400rwhp.

 

I like their relative simplicity and minimumilist approach, plus I suspect they are a bit lighter than their twin cam brothers, particularly up top.

[mtcookson]

the VG30E(T) is an awesome engine. there're quite a few Z31 guys making well over 400 whp to my knowledge. compared to the VG30DE(TT) and VQ it doesn't have quite the potential simply due to the dohc engines' being able to breath more but the VG30E(T) can make plenty of power for most people.

 

what's really cool is they're actually a very light engine for a iron/aluminum V6. i believe the early vg30et's weighed right under 400 lbs dry (i believe around 396 lbs.) when the Z31 first came out i believe nissan boasted that the VG30E(T) was the lightest V6 to ever be produced at that time.

 

i actually know a guy who messes with buick grand national engines all of the time and picked up a maxima with the vg30e. he eventually turbo charged it and in the process took things like oil pan off and heads off during the buildup to do a few things and basically flipped out when he saw how the engine was built. the vg's came stock with a massive girdle to tie the main bolts together (which is a modification a lot of domestic guys do to the v8's and he mentioned the gn guys do that as well).

 

when he took the heads off he was amazed yet again at how well the heads were clamped down. nissan used 13 head bolts per head. the grand national used 8 per head and he mentioned a common modification was to mod the heads so that they could use 12 head bolts.

 

kind of shows how nissan over engineers their engines to make them incredibly strong. i believe one of the Z31 guys was pushing a little over 500 whp on a stock block pathfinder vg30e (i'll have to search to find out for sure but i'm pretty sure that's how it was). basically, these engines are great and as you said, very simple.

[Guest Jason84NA-T]

.....Around 400 rwhp would be the aim.

 

Anyone have any idea as to what head mods would be required? Rockers? Lifters? Plenum?

 

mtcookson's information is accurate. But you would not need any modifications to the engine/heads to hit 400RWHP. Just a better flowing plenum, larger turbo, IC and a good fuel solution will get you there. The VG30's bottom end is rock solid to just shy of 500RWHP where you will start busting the ring lands off stock pistons. Stock "redline" is fairly conservative, but considering with the stock turbo/heads you won't make any more power over 6500RPM anyway, it was probably a good idea for them to put the stock rev limiter at 6450. If it's worth anything I have never seen a busted stock VG crank OR rods related to power loads.

 

current "record" with ported stock exhaust manifolds on a VG30ET is 745rwhp, and he runs 9's. Mike DeBusk in florida is making ~660RWHP with ported stock manifolds.

[mtcookson]

I agree with everything you're saying, however having a higher redline actually does help out. I'm not sure if its just because it drops the revs into the powerband at a better spot or what but for instance there were some Maxima guys that had nearly equal mods. One had a JWT ecu with the 7k rpm redline and the other guy had a different mod that the JWT max didn't have. Both basically produced the same power however one could rev to 7k rpm while the other 6k. The JWT Maxima was always faster when revving to 7k but when they both ran them to 6k they were nearly equal. with a turbo setup I believe the gains would be even better since boost would help out the top end quite a bit.

 

Get a set of cams and upgraded springs and that thing should pull hard up to the 7,000 rpm.

[260DET]

Excellent info, thanks very much for that.

[ZROSSA]

Dont forget that nissan used these engines in there imsa sports cars. Richard , you should remember those cars. Raced by one of the Brabham brothers and they won a few championships with it. They started with the sohv v6 and made huge power with them. Something like 1200 in qualifiing if i remember correctly.

 

Douglas

[Guest Jason84NA-T]

Dont forget that nissan used these engines in there imsa sports cars. Richard ' date=' you should remember those cars. Raced by one of the Brabham brothers and they won a few championships with it. They started with the sohv v6 and made huge power with them. Something like 1200 in qualifiing if i remember correctly.

 

Douglas[/quote']

 

Well, electramotive actually did the work; Nissan just gave them the money. Qualifying trim power levels were in the 1000+HP range. With electramotive's fine work on their new chassies they DOMINATED GTP in 1988 and 1989. The engines used stock heads and stock blocks (until casting the block in aluminum about two years later solved some durability problems). A good book to read if you are interested in the subject is "Lightning Speed - The Nissan GTP and Group C racecars" by John Starkey. I believe he had some copies on ebay, or you can get it through amazon.