Pyro

I used a T04B-H3 compressor because I didn't want to add a turbine spacer since my exhaust was already in place. That was a mistake. I should had installed a T04E-50 and had a better compressor for the L28. I used a MSA turbo stage 1 cam. It has wider lobe separation (114 degrees) but still has more overlap than a stock NA cam (3 or 4 degree more, I forget). I didn't try the msa cam with the stock turbine but guess it would have a little too much overlap for the stock turbine. (just my opinion) I used a stage 3 turbine which makes max boost between 3500 and 3700. And the cam pulls to around 6800 rpms. I use 12 to 14 psi of boost and it starts to boost after 3000 rpms. It is much faster than the stock setup (at the same boost) but it does't feel like it. I know that sounds weird. I guess because the turbo hits much softer than the stock turbo and the power is in the upper rpms which I don't drive in as often. Plus the bigger cam and turbo requires downs shifts to accelerate where the stock turbo and cam didn't (lots of low rpm torque). I'm glad I used the high flowing turbine because the T04B-H3 would surge if it made boost any lower in the rpms. This is not the case for the T04E-50 compressor. If I had to do it over again, I would use a T04E-50 compressor, one stage up from stock on the turbine, and use a stock 75 to 79 NA cam for 8 more degrees on duration. I'm not looking for max power. I want a lot of torque at low rpms (fun street car), a good idle, and power to 6000. The stock turbo cam stops pulling too soon (5,000 to 5,500 rpms). I'm also guessing a high flow down pipe could release some extra manifold pressure which could help the stock turbine handle a NA cam.

I upgrade the stock turbo and cam on my car. sure it's faster but I do miss the low rpm torque of the stock turbo and cam when driving on the street. It was fun breaking the tires loose in 3rd gear at 3000 rpms. With the bigger cam and turbo, the engine now requires 4500 rpm to break the tire loose in 3rd. So, I find myself going way too fast on the street to get that pushed back in the seat feeling. If I had to do it all over again, I would had left the stock cam and turbo in place. Or maybe just upgrade the compressor.

The stock NA cam is only around 248 degrees duration and the stock turbo cam is around 240. The stock turbine makes boost very quickly but at the same time it is very restrictive which causes lots of exhaust manifold pressure. So, the turbo will not do well with any valve overlap due to the reversion into the intake from the high exhaust manifold pressure. If you use a high flow turbine, the boost will come on later and the exhaust manifold pressure will be less. Therefore, a cam with more valve overlap can be used due to lower exhaust manifold pressures. If you plan on staying with the stock cam, then the stock turbine works well. However, the stock compressor gets pretty hot after 12 to 14 psi of boost. It is worth the money to get the proper sized turbo. A T04E-50 trim is the right size for most L28et applications. Then modify the stock turbine if the cam will be changed. For example, use a NA cam with a stage 2 turbine modification or get a stage 3 mod turbine for a MSA stage 1 turbo cam. But first, change the efi system if you can. The stock turbo can make good street power with little lag and lots of low rpm torque which is fun on the street.

low on money. stock 81 to 83 L28et with megasquirt efi, 14 psi, and IC. Makes a fun street 240 that will run 12's in the 1/4 mile with fresh tires on the rear. And will work with your current drive train, cooling system, alternator, and engine mounts.

typically called a 3.54 39:11 = 3.545

I think you are at the limit of the stock system. You need to add more fuel pressure while on boost with an FMU. Your pressure gauge could be wrong. I think stock is 7 psi so maybe your already at 10 psi (not 9).

What rear end are you using that is a 3.63 ratio??

Will a T70 work with a 2.0 liter? I tried a turbo sizing site and couldn't get to the right side of the surge line with a 2.0 liter and a T70 compressor.

My Deltagate seems to work well. I'm running a T04b-h3 compressor with a stage 3 T3 turbine with a MSA stage 1 turbo cam. 2-1/2 inch exhaust

Seems very high to me. 180 psi should be the value with a 1mm head gasket, so 200 with a 2mm gasket doesn't make any since. I would try another gage.

here you go http://www.chevyhiperformance.com/techarticles/148_0401_chevrolet_406_ci_engine_build/index.html http://www.chevyhiperformance.com/techarticles/148_0306_chevrolet_406_big_block_torque/index.html

I would use small ports, like vortec heads. Chevyhiperformance.com built a 406 with vortec heads and made like 530 ftlbs and 470hp with a moderately sized hydo flat tappet cam. The cam was around 230 degrees at 0.050" but the small ports made huge torque and fairly good hp. ran on 87 octane too. I think it had 400ftlb of torque at 2000 rpm. do a search on that site.

I would keep the stock turbo and spend money upgrading your 25 year old efi system. The stock turbo makes nice power even at 14 psi with a good intercooler. It can make 250hp at the wheels easily. After you get your new efi going, then upgrade to a bigger turbo. It you use the stock cam then use a stock turbine. If you install a better flowing turbine then install a bigger cam.

A NA trans is plenty strong. I have run 14 psi with an aftermarket cam and big turbo for 4 or 5 years now with no issues. Tires will spin before any problems. And I drive my car hard (full boost and 6500 rpms every time I get in it). However, the stock NA 225mm clutch will not hold for long. Get a 240mm setup from a 2+2.

check out this 76 280z L28 turbo with automatic transmission

cheaper to add a big turbo and efi system to what to already have. There are lots of hidden/unexpected costs with a V8 conversion. Plus the amount of labor will be 2 or 3 times more than what you plan for. A L28 turbo can be just as fast or faster than a 400hp V8. install stage 2 or 3 MSA turbo cam, T04E-50 turbo with a stage 5 exhaust turbine, intercooler, and megasquirt efi. Could make 400hp with around 17 psi of boost.

205 to 210 psi is a little high for pump gas, right? what compression ratio and cam spec?

I'm sure the pump and line are enough to spin a tire. Getting there with the specs but need more please (help us, help you). now for the gear and stall converter. Can you look at your engine specs and see what cam they gave you. what ignition timing are you using?? (initial, total mechanical, vacuum advance) tell us about the exhaust system. how did you set up the TV cable? tune the carb any???

I think that would work ok. running the exhaust under the oil pan is not that far. you could even use a stock NA exhaust manifold which would flow much better than the turbo manifold. single turbos on V8's or V6's run the exhaust to the other side, so I don't see why you can't. Maybe you should use some header wrap on the exhaust pipe that runs between the turbo and the manifold to keep the exhaust temperature up. Not a bad idea. I wish I would had thought of that.

Wow, you got that thing in there! is your engine in the set back position? exhaust routing is always a problem with automatics. that big oil pan is a problem.

400's are huge. I have one in my truck and can't image putting that thing in a Z. I had it rebuilt last year and getting that mass of aluminum back onto the back of that 454 was tough. I would use a built th350 before using a th400. A th350 built for drag racing can handle lot of hp. install a trans brake and a manual valve body. A th350 can handle your engine easily if built right.

Which ever efi system you get. Make sure to get one that handles ignition timing control and low impedance injectors.

did you use the 1/2 inch body spacers as described by JTR?

good numbers for a cam and su's. I bet it runs pretty nice even without the turbo. how much timing did it need to make max hp? did you use SM needles? edit: got it. the answers were in the first post. to go from 167 hp at the wheels to 425 hp, you will need 23 psi of boost.

I wouldn't run a cam with more than 215 degrees duration at 0.050" with a stock converter or less than 9.25:1 cr or less than a 3.50 gear. Over camming is a lot worst than under camming.