Thread: Questions about budget turbo build

it'll prolly be best if u just give it to me. ill put my p11 trans in it, build my bottom end, ur head, then let it sit outside with no hood or valve cover til summer, then fire it up.

as far as school goes, i been takin him to school for almost 2 yrs now. he's learned more workin wit me, than that school is teaching him lol. "octave"s buddy in clarksville has a tubular top mount that was built out there. its a freakin beast. from the primaries, it goes down to the bottom of the car, then swoops back up and puts the turbo bout where the battery is. i want one, but stay na; jus have a stack.

Unless you just REALLY want a top-mount for looks, why not go with something similar to this? Would this work better with a ve head?

^ THAT is exactly what I'd be interested in. I dunno really how I'd make this huge turbo fit in there though with my Mishimoto radiator. Would that type of manifold flow better than a log style? Nice oil feed btw lol


Haha, well yeah, you done learnt me a lot. I've been learning a lot about brakes at school, though. I finally understand drums and drum and hats. Hydraulics are simpo, too. But you got pics of that manifold? How much does he want for it?

At least I'm not spending $2000 on a GT3076r. I'd say it's pretty cheap for 400 hp

This was just a test fitting. I had to cut the flange and turn it just a little more to clear the lower motor mount.

Yeah...I thought I had enough length in the hose to reach. lol. I had another hose made from high-pressure fuel line. No ss bling for me.

Thing is though, with a bottom-mount, it's not as easy to keep the a/c compressor. That's the closest I could cut that 3" downpipe.

Stratton.

School is over-rated.

Would a mazworx DIY ram horn manifold flow well?

I would go this route. Keep the runners as long as you can for the best scavenging results and nearly zero loss of response. Ram horn manifolds work great!

The chambered design of the log manifold, coupled with 48* overlap on the stock cams, causes a lot of unwanted reversion. With my GT3076r with a .63 housing, the reversion was enough that the car LOST power when the VVL hit. A larger turbo or housing would only bandaid the problem. I had to go with the VET cams to make big power. Bolt in cams made over 100whp more on the same boost pressure!

Now I've played with the stock cams and a tubular manifold and the stock cams work amazingly well. Made the same power with the stock cams as I did with the log manifold/VET cams did, but it did slightly better with the tubular manifold. Unfortunately when testing this tubular manifold I was running a .78ar divided housing. MUCH too small. Trading up to the 1.06 housing made 30lbft more torque and 20whp increase. Spool was better and mid-range power showed gains as high as 40-50whp iirc in the midrange.

After finding out the motor had low compression I rebuilt it and put in SR16 cams. On 10psi it made 319whp and 16psi made 390whp iirc with a conservative tune. Last dynojet numbers were ~480whp on 26psi and a fat powerband peaking at 7800rpm. The SR16 cams peaked out about 400rpm later, and didn't really affect bottom end power that much. Maybe a couple hundred rpm was a little slower. The power in the mid-range increased yet again with the 1.6 cams but power on top seems to drop still.

Now the power on the top end seems to drop because of the backpressure in the turbine housing. The 2.0 VET cams didn't seem to drop as severely as the 1.6 cams do. Even though the 1.6 cams peak a little later and it makes more power. The torque curve drops quickly after the peak hp.

The 1.6 cams may not be scavenging as well on the top end due to 70* overlap and the building backpressure in the manifold. The only way to really make use of the better scavenging of the high overlap cams is to run low boost and rev, or to lower the backpressure with a larger turbo/housing.

The 1.6 cams should really only be used with GT35r turbos, and though this is my speculation, I am sure my dyno results will concur as to these assumptions. 2.0 cams will still work really well on the GT35 based turbos and will provide a broad powerband, the 1.6 cams will just use less boost to make the same power. There is always a trade-off.

My goal is to eventually have a GT35r based setup that has a lot more useable power in the midrange. The GT35r based turbos seem to be really laggy for a street car, but I hope to be able to make something that performs a bit differently. A RESPONSIVE setup with a big turbo is the goal. Who knows, I may end up going back to stock cams to see which one works better. But I am sure with the GT35 turbo the sr16 cams will really come alive.

Just don't use restrictive exhaust/manifold/turbo on the VVL. It is pointless to have a vvl if you do that. The GTiR manifold will likely outperform any log manifold out there.

Pro-tech did make a shorty manifold for a great price that others have had great results with.