Clifton

I ran the Rebello/BHJ one because I needed the pulley diameter for the SDS magnets. If not I would run a ATI one. I'm now running a PT or SC61 (GT35r compressor, P trim .58 hotside). The most I've run on this one is 20 psi. 8" coils and the right offset and 275/9's will fit. I've posted the offset but unless it is on the same rear brakes it may not fit.

You won't make 500 with 20 psi on a stock head. Maybe 400. Honda's heads are alot different better than a 2 valve Datsun head. You can get undivided housings for GT40's in .68 and .81. When I dynoed mine it had stock everything but valve springs and intake manifold, port matched and cleaned up the bowls. It will rev to 7500 no problem but I like to keep in under 7k unless I have to go higher to avoid a shift. I have a dyno posted somewhere with the old turbo.

IMO, If you want 500 rwhp go with a GT40. The GT35 would easily do it on a better similar sized engine but a stock L lacks airflow. I'm not saying you can't do it but at what boost? The internals aren't what's limiting the HP on these either.

Sure, stroke it to 4.5 liters and put a head on it that will flow and it would be streetable.

Plus a FLAT PLANE CRANK and cams to match:ugg:.

At a 2.0:1 pressure ratio and using 20lbs/min, a 62-1 and E57 will be under the surge line were a 60-1 is a little above it. If you turn the boost down to say 10 psi will it go away? This only happens at lower rps right? Any chance you have video of it on the boost gauge. If I had my other turbo on I could go get a vid and see if it is what you are describing.

The valves are pretty big to begin with, larger than VK45's. You don't really need rods (it's not a Chevy), just pistons if you want alot of boost. Cams aren't cheap. I would just do pistons unless you are after every last bit. Cams http://www.camshafts.co.nz/Nissan.aspx#VH41-45 This guy made 446 rwhp with 6 psi, stock motor. http://forums.nicoclub.com/zerothread/296413

Looking at a 60-1 map, assuming it's using about 20 lbs at 15 psi at 3000 rpm( probably less with 30% throttle), it would put you just in the surge range. I guess it depends on where you want the power and if max power is your goal. If you go smaller on the compressor side you can pick one out of the surge range and keep the fast spool. If you want max power and don't mind a little lag to get more then going bigger on the exhaust side. Changing a compressor wheel and getting a new compressor housing to match is expensive. Swapping the turbine and /or housing side is expensive too. Either can make the HP but the larger hotside would to it with less boost as it would have less back pressure. Looking back at one of your posts you mention this That's exactly what mine would do. Part throttle/ light boost through a long turn and you have to hold the peddle there regardless. If you do alot of track days I would go bigger on the hot side. I went a little bigger and it's not even noticeable on the track as long as the revs are above 3500. On the street you could drive around it.

Your rpms can still increase as it's making power, the boost is fluctuating from the air stalling (surge). If you could do it at WOT in a taller gear you would get to a point were the engine could use the air and the surge would stop, if it didn't kill the turbo. I'm assuming it's a V or H trim is it's a T04B. If it's making that much boost at 30% TP with a V trim at that low of an rpm, it's compressor surge. The cheapest way to slow it down would be to go larger on the hotside a/r, like a .82. Going with a stage 5 wheel would work too but you would need to machine the turbine housing for it. I ran a full TO4B/ V trim compressor, O trim turbine (bigger than a stg 3) .69 a/r (alot bigger than a T3 .63) and could get it to surge at low rpms, part throttle.

To add to what Perana said. The dynos I've seen 1uz make in the 170's and VH45's in the 240 hp to the wheels. Plus the extra torque.

Mine is 24" and I had to cut the core support to get the in/out through and the hoses barely touch the hood hinges. This would have half the pressure drop. I don't know if a lower pressure drop or longer tubes makes more power though. http://cgi.ebay.com/ebaymotors/TURBO-INTERCOOLER-22x6x3-Supra-7MGTE-1JZGTE-Mustang_W0QQitemZ270217548469QQcmdZViewItem?hash=item270217548469

You should have set it on megatune. Check it though, should be 0% without touching it and 100% at wot. If your TP setting is set on megatune then it's right, but 30% throttle isn't much to make that kind of boost. If you open the throttle more the surge goes away and the boost needle stabilizes right?

I run 250 f / 280 r but with Koni's on my 73'. I like it. Yours is 300 lbs heavier than mine too. I run alot stiffer on my 71', I wouldn't want that on the street.

On line 3185, you are at 3300 rpm, 180 kpa but it looks like your TP is only 33%. On another one you make 200 kpa with 33% TP at 5200 rpm. Is your TP % correct?

I thought it was WOT. Is it steady state part throttle, just cruising with no change it TPS?

Anyone know if the 280 center panel will fit a 240 dash? It looks like the 280 has larger center vents. I just looked some up on ebay. Looks like a no go. Has anyone swapped a 280 dash into a 240?

There's the problem. I run barely any in the rear but crank it in for autoX. R comps with zero camber are more than enough for turns on the street:wink:.

A BOV only vents on closed throttle. If the turbo isn't matched and it surges under load (WOT), no BOV will help that. Maybe you meant that but just wanted to clarify.

If you only surge above 3500 but can make full boost below that, I don't know if it's surge. As the revs increase the airflow requirement does too and reduces the chance of surging. I would think it would be in the 2500-3000 rpms range with that turbo.

I wouldn't pull timing after 4500, it's not helping. I would drop timing around peak torque and add it in after up to redline. It looks like most of the timing you pulled was off boost too and after 3400, I would start adding it after 3900. One way to rid it of surge would be to pull alot of timing at lower rpms were you are experiencing surge.

I don't like sharing the road with drunk drivers. Hopefully you'll get some jail time and learn your lesson.

Yes max flow is 47 lbs but not max boost. There's no reason to run it out to 47 lbs. That turbo on a smaller engine would be fine at 30 psi if not run past 70%, right around 40lbs. I guess not many on here like to run high boost though so it shouldn't matter. If he gets the boost but it will be way too small.

That'll do 35 psi easily. It might make 450 rwhp but if that is the goal it is on the small side for sure.

That's it? Come on, details. Looks pretty bad. Was everyone ok?

HF usually has cheap DVM's for around $5. Cheap the voltage at the battery or straight off the alternator. Check it before you start it, when it's running and with the lights on. Even with all the acc on it shouldn't go below 12v. Rev it to 2k and check it also.