evil00017

I noticed today that MVP is offering complete built heads that look like they have been ported come with a new cam profile and new valve springs.

Is the idea of a fast GS4 N/A actually feasible now without blowing outrageous wads of green?? What do you guys think?

heres a link: https://www.clublexus.com/forums/sho...99#post3824799

PS: It would have been really cool had I spelled cylinder right in the thread name... ooo well.

JeffTsai

iTrader: (1)

That's still going to be quite a bit of green. $6800 for the built head with no extra options. Then you will also want to get the bottom end built to withstand higher RPM...I'd say that would be another $4k or so. You will also need to upgrade the transmission to shift faster(about $2k). Also, it would be beneficial to buy a high stall torque converter and possibly an LSD(another $2500 there). You might need to upgrade the fuel system if the engine puts a lot more power than stock($1k). Then finally, you might have to run a standalone system($2.5k wire up and tuned) since I don't know how well the stock ECU will hold up when you're revving to 8000rpm lol.

Add all that up and you're looking at around $19k to get your car to be a NA monster. I'm not saying that it won't be fast. With that kind of build you are possibly looking at putting down around 400rwhp. It would be impressive power out of a NA 4.0L V8. But personally, I would spend my money on a different approach to get more power(forced induction)

mtparker18

I'd turbo or sc it and get it over with. like Jeff said, its going to be like $19k. you could prob spend at the most $9-10k for a turbo or sc for your car.

c0wboy

Just for information purposes, you can figure that 19K on top of any FI project. None of that stuff has to be done to swap cylinder heads.

Thanks,

Eric

JeffTsai

iTrader: (1)

c0wboy, I'm sure you're a bit more versed in the Toyota V8 than I am. But, in general for any engine isn't the whole point to have a built head with upgraded valvetrain and camshafts to raise the redline and flow more top end? Then if the revs are to be increased, the bottom end will need to upgraded as well. I'm just saying the whole complete package to get maximum benefit would cost $15k+. Obviously you can bolt on the upgraded head onto a engine that is otherwise bone stock, but what is the point? You will just be wasting a good bit of money and not get all that you can be getting out of the upgraded heads.

c0wboy

That's not the whole story on the V8. You can raise the redline, but on these V8's I'm not convinced it's needed on a street car. My position is that power band falls off directly in the midrange, and there's a lot more to be had in the stock upper rpm's. More aggressive cams, slightly larger ports, and larger valves will help open it up quite a bit. If someone wants to build their V8 all the way, I'm not going to say it's a bad idea, but in this instance and for what many on the forums are looking for, it's just not needed.

On the other end of that, the second anyone begins to consider Fi, they should also deeply consider all the mods that you listed. Again none of it is required, but on a Fi motor it's all a grand idea for the longevity of the project.

Thanks Jeff!

Eric

HI98GS

Eric,
Why didn't you tell me that "none of it is required" before I went down the slippery slope hahaha. But this is one hell of a ride. hmmmmmmm I see a bump up ahead. . Let's go faster.

But on a serious note, These goodies aren't for the weak at heart, you gotta want to really do this. I can't see someone just sticking their toes in to test the waters, unforunately there aren't enough aftermarket perfomance shops that will make stuff for the 1-3 uz. Watch when the new supra/LF-A comes out, prices for parts will be outrageous. We get what we can get.

Keep up the good work
aloha
HI98GS

JBrady

Eric, are you aware of a way around the factory rev limiter?

Looking at the pictures posted it looks like the exhaust ports have been opened up a great deal. Do you have the exhaust inside diameter measurement?

What testing has been done? Dyno, power, torque, driveability?

Do you have a list of recommended support parts such as headers?

Pic I am referencing for the exhaust port size comment.

c0wboy

Those are the ports on my personal heads. My mods list includes twin turbos and I wanted the most volume possible so we went aggressive. My ports on my personal head we're opened to 1.75" (from 1.5") to match the ID of the turbo mani's. On an NA though obviously the porting is much, much less aggressive. We go just beyond a mild casting cleanup. Recommended supporting mods on these in basic. An intake for certain, and owners choice as far as any sort of aftermarket fuel control is concerned. Headers are also on the list, but I can't recommend S&S because they're rubbish and will crack within 90 days of install. I don't have a way around the factory rev limiter other than a standalone. I'll have dyno sheets and reports on my personal motor shortly, however being a turbo motor I'm not sure that it will apply. No back to back testing has been done otherwise by anyone as far as I know. The V8's are still in an infant state in comparaison to other more well known platforms. What performance upgrades we perform originate directly from other more popular V8 platforms such as more aggressive cams, larger valves, valve springs, and a mild street port.

Thanks!

Eric

JBrady

Glad to hear that.

Not certain if you mean the manifold or the air filter to throttle body. The factory intake manifold is a very nice piece of engineering.

You are entitled to your opinion but you are way off base claiming they will crack in 90 days. The early design tended to crack after several thousand miles. S&S changed the pipe thickness and welding points. I don't recall hearing anyone with the redesign having cracking. As far as street performance I haven't seen a better performing header... yet.

I am very interested in seeing how longer duration camshafts interact with the VVTi system. There are definitely some points of concern with advance and overlap. Need to see how this combination behaves in street driving and in what way it effects the drivability and durability.

c0wboy

JBrady, I'm in posession of two sets S&S headers that have cracked within an inch of each other, on the same side. The material is paper thin and made cheaply. There are spot welds in areas that could use reinforcement and hardly any support in areas that breath heavily under throttle. I'm not going to get caught up in a debate about these though, I just wouldn't recommend them to anyone unless they want to be taking them on an off their car often. MVP will be putting up a V8 twin turbo kit later in the vendors section, and in there you can a set of manifolds with good detail. The differences are apparent straight way.

The 208 cams in MVP's cylinder heads are not so aggressive to cause piston to valve contact. There are cam profiles that do however, and with those the VVt-I has to be carefully controlled. As far as street driveability and duravility, I don't think anyone with an ounce of common sense would believe that their car will behave or sound like grandma's grocery getter with a set of modded heads and a set of more aggressive cams. Instead it can be expected that the car will wake up and have some aggression for once.

Eric

JBrady

Eric, you are welcome to call me John. As I said you are certainly entitled to your opinion and free to post it. All I ask is accuracy. You would not want someone making exaggerated claims about parts you carry. I am not in the loop with S&S but feel some degree of obligation to keep the record accurate.

"paper thin" is an exaggeration.
"made cheaply" is inaccurate (thick flanges, mandrel, merge primary Y's, Jet Hot coating).
"crack within 90 days" is an exaggeration.
"rubbish" is an exaggeration.

May I suggest; too thin, history of cracking and simply not recommended. That would fairly relate your opinion without excess.

Now, too be fair you need to specify whether your "sets" are first generation or the re-inforced upgraded generation of S&S headers? As I mention I am unaware of problems after thicker tubing and re-inforced welding was implemented. If you have news to the contrary please post it or write me and or S&S as Loren would certainly prefer NOT to have warranty claims.

You do not want to debate but it was your posting as mentioned that started this in this thread. The "spot welds" you mention are simply welds that hold the pipe in place prior to the 360 degree welding on the flange inside. This is a VERY normal header construction technique and arguably is less prone to cracking. In fact I am unaware of ANY failure of any kind related to the areas that are "spot" welded. Again, if you have news... post it.

I do not understand your report of "hardly any support in areas that breath heavily under throttle". To what do you refer?

Just for the record S&S owner Loren Barnes years ago had a young man working with him by the name of Jack Burns who has since gone on to open Burns Stainless (probably the highest regarded header builder in the business). Loren has been building headers longer than many on CL have been alive. The very fact that he COULD build these WITHOUT a car!!! speaks decently of his ability. Their performance is documented. Reliability of the first generation proved problematic. Second generation??? S&S has honored all warranty claims I am aware of. Perfect? No. VERY few aftermarket parts are.

I look forward to seeing more. I have more than a passing knowledge of aftermarket turbosystems and what it takes to build a reliable comprehensive system/kit. Hopefully you will not find yourself in the warranty business.

While piston to valve clearance is important (and presumed checked) the way the vvti works is to rotate the intake cam relative to the exhaust cam. This is not an on/off action and when the intake retards overlap is reduced and valve closure is delayed. When advanced the valve opening is sooner as is closure. This is a catwalk and tricky area. Longer duration cam profiles will have some unexpected results as the vvti programming moves things around. This is NOT the same as throwing a bigger cam in a non-vvti engine. That is why I asked for testing results. Sounds like they are up and comming as you get your turbo engine together. I am sure you will keep us posted.

c0wboy

Hi John,

I couldn't remember if your name was John or not, so I went with the safe bet

On the headers, the gentleman I go tthem from was 1TYTESC here on CL. Billy would have to call out how old his headers are, but on the two sts that I have from him, 1 set broke 330 degrees around at the weld, and another set broken 330 degrees around on the tubing itself. The material seems to be ~.048 thick and looks to be made of a mild steel. For reference, check out MVP's turbo manifolds. .125 thick 304 stainless, reinforced tubing, welded to the flanges both inside and out.




Even though most folks opt for an NA appication, but really I believe that the headers should be made in the same way. It's more expensive, but not as expensive as sending out free manifolds due to warranty concerns.

The numbers from the turbo kit should be coming out soon. I'm not looking for much, but I want a quick spool and ~800rwhp or so. Not earth shattering, but gutsy.

You're on the button about the VVt-I mechanism. The more aggressive profiles will need VVt-I control, and the most aggressive profiles will have to have the VVt-I swing cut down to avoid piston to valve contact. For reference, here's what Ed Morris from the AU made on his 4.0L VVt-I with a killer set of cams. He has an outstanding set of supporting mods,



Ed's a real pioneer in Toyota V8 NA power, and I admire his determination very much.

Eric

evil00017

Was ed morris car a GS? How come up until now i have never heard of anyone doing cams to the car? I heard of people doing exhaust cam and such but from what I read it was kind of sketch. I always thought if you were to do some cams you would need a standalone but you are saying you dont need to.

c0wboy

Ed's car is a MKIV Supra with a 1uzfe VVt-I dropped in. He's running a manual transmission, built motor, ITB's and a number of other supporting mods. If you want a standalone then that's no problem, but the cams will run without them. The GS400/430 runs on a MAF, so what's it's reading is air coming in.

Thanks!

Eric