Thread: Think I went with too big of a turbo...

It is harder than it looks, I can tell you that from personal experience. Getting a nice even, clean bead around small tubes with tight bends is not easy at all. Granted I don't do it everyday but there are reasons that all the manifolds you see for sale are tig welded. I just don't want to see this end up a waste of time and money as you know how I feel about the idea anyway, if you are going to do it, might as well do it right and have something to feel proud of when you pop the hood. I can mig weld pretty decently and I wouldn't bother trying on a manifold. I'm sure with enough trial and error it would work but it certainly will not look great and be very frustrating to say the least.

The people who actually make the manifolds that are sold have years of experience. Becoming a good welder takes lots and lots of practice and advice from people who have learned from years of experience. This is not a knock on you V but there is also a reason that they charge so much for nice exhaust manifolds. I would rather just pay for a short ram manifold that is already done and will work for what you need it for.

If you insist on designing your own I commend your bravery but I would spring for a pro to tig weld it after you tack it. I will say it again, experience is what makes a great welder. Even a decent welder needs hours upon hours of experience, hours like many of them, not just f'n around on scrap in your spare time. That is why welding is a trade in of itself that people get paid very well for.

Think this all the way through V. I think that paying to get your car on a dyno as it sits would be worth much more than spending money on a welder and hours upon hours in design and practice. I think of time as money as you should too. With that being said, once again it is your car, have at it. Just giving my 2 cents. I still vote bring your car up to CT and get it tuned as it sits. For some reason in CT and Florida, people make good numbers with simple setups such as the one you have now and no we don't have magic dynos, LOL.
Drew

I still think going to the dyno as is, is a bit waste of time and money. Especially since I wont be keeping the setup anyway. I was going to keep the log then sure it would have been fine.

I spent a great deal of time porting the intake runners, porting and polishing the intake manifold, throttle body etc. As BenFenner told me before I went log, that's all negated with a crappy flowing log manifold. Anything I do to keep the log is a bandaid, this is why I gave up on even trying to get VET cams. Crappy flowing manifold is just keeping the heat inside the engine longer and even with lighter timing my spark plugs are showing high cylinder temps.

Plus I should see better gas mileage numbers with a tubular manifold .

Now as for welding it, if I can't get good beads, I will tac it and take it to Keo . But I wont give up without a fight, it's just not in my Russian nature. You'll have more luck sending me to Gulag Camp first

When can we change the title of this thread to "Think I ignored too many people's advice about log manifolds on VE engines..." ?

How do log manifolds function on DET motors?

Less shitty than on VE engines because of the DET cam design (low overlap). Still close to full shitty though.

Lol

I had two people tell me that logs are bad on VE. You and Lynch. Everyone else, including some senior knowledgeable members said Logs work just fine for under 400whp.

Either way, in the back of my mind, I always wanted a tubular manifold, just never wanted to dish out $1k for a good one.




DE cam overlap is 16* for 91-94 cams, and 8* on lowport cams.

VE cams have 48* overlap on the big lobes.

Now S4's, which are considered to be good turbo cams, have rather high overlap of 28*. But I think the DE headflow is what makes that be not as bad.

28* isn't that bad of overlap for turbo. Even guys with T25 still prefer the S4, even though S3 perform better for T25. S4 and a good size T28 can make really good power. We made 300whp on 14psi on a basic T28 and S4 cams with a 2.5 exhaust. It worked well.

My old disco potato car made 340whp on 18psi with S3 cams, and that setup was far from ideal. It just worked. But both of those cars used stock manifolds, not logs. The stock manifold is built sorta like a twin scroll, and separates pulses to the collector. I'm pretty sure for any T2 flanged turbo, the stock manifolds will outperform pretty much any offering in log design.

After having gone with log, vet, and now tubular, I can tell you that the manifold and turbo sizing is everything to do with a well performing VE setup.

Still, for my turbo size, I think I made really awesome power on my log setup with VET cams. I mean, I have a 60mm turbine and a .63 housing. Still made 445whp on 24psi

You know which wagon I was on.

Fixed?

Yah, I can't imagine you weren't telling Vadim the same thing Lynch and I were. Right Vadim?