Rudi

I didn't know seatbelt and window wipers were unnecessary. Going from 35mm to about 15mm on the main coolant lines is a great idea as well. The temperature sensors are mounted on the wrong side of the radiator, giving the ecu and temp gauge false readings. And 50 engine bay picture, and not a single picture of the drivers side of the engine (bay), too ugly for pictures? Nice how someone tries to make nice looking car. But when the car becomes inferior and technically dysfunctional as a real road car thanks to the mods done I fail to be impressed. Perhaps I take 'tuning' a bit more serious than others.

I managed to get the car back to stock, easier said than done. During the assembly I somehow managed to make a stupid mistake, the injector plug for cylinder 4 didn't secure well, skipping the 4th cylinder for a few km's. I checked every plug twice but this one somehow skipped. Also, after a test drive the 6th cylinder went dead as well, and the 1st injector leaked towards the upper side of the fuel rail, I should be lucky it didn't get worse and the car didn't burn down. The cause of this is the incorrect fit of the 'Buna' fuel injector seals I bought through CZP. They're way to thick and I could barely fit the injectors into their rails. So injector 1 leaked towards the outer part, but I suspect number 6 did it inside of the intake port. This flooded the cylinder killing cylinder 6. Lesson learned, always buy OEM fuel parts. Note the difference. OEM left, Buna right; Now the dyno results. The car runs much better with the stock manifold. You can really feel that the tune is correct for this type. Despite running quite smooth throughout the rpm's, during the first run the engine went extremely rich again at just 242 rwhp, note how the AFR falls of the scale like it did with the manifold as seen in this topic. So I pulled and plugged the vacuum hose again and the power rose to 255hp just 3hp over my custom manifold, and 8hp less than the ITB setup. As can be seen in the dynosheet, both the ITB (blue line) and custom manifold (red line) take the lead from a low speed on. At 135km/h the AFR went very rich on the custom manifold and the stocker (green) takes over shortly, staying close till the last top end where the AFR screws up again on the custom manifold. The ITB setup is by far the best over the entire rev range, take into account that that setup wasn't done with a pulled vacuum hose so likely too rich as well (the AFR recording was faulty during the run so no comparison, but note the power drop at the end just like the very rich custom manifold). The overall design still makes it a winner. It all sums up pretty well. The custom manifold from this topic couldn't perform well as the ecu made it run way to rich, I guess a boost leak or dirty MAF as the cause. This killed the performance of it, and I feel it should be right on par with the ITB manifold. The stock manifold has the primary advantage of being tuned for the setup, giving it a false start. Add to that the effect of the stock turbo's, which were designed to work with the standard manifold's performance areas throughout the rev range. I also expect both the ITB manifold and this custom manifold to respond much better to uprated cams. At a stock stage a custom manifolds seems pointless for the marginal power gain, the money could better be spend on other parts. But at a higher state of tune, where all other 'breathing' parts have been uprated the stock manifold becomes one of the next steps. Now it's time to test one on a tuned 300zx.

Unless you must use adjustable arms for alignment settings I'd say keep the stock arms. You're getting more noise and vibrations in the cabin for next to zero cornering improvement. If you dig through the old books on the development of the Z32 suspension you'll understand where I'm coming from. + Most adjustable rear arms are in fact heavier. You'll find more improvement when it comes to tension rod bushings, subframe bushings, chassis reinforcement etc.

I don't know if a strut bar will, depends on the type I guess.

Thanks. A solid linkage does not work, I've spend hours figuring out the right angle for the TB's, and due to their position there's no reasonable way to fit a solid linkage. The BDE's would fit by moving the AAC unit somewhere else. On the side of just 1 plenum could be done but I don't know how this will affect idle stability. I just finished the manifold back to stock. Just need to adjust the idle and fixed a cracked brake booster hose and the 100% stock car will see the dyno next week. - - - Updated - - - Thanks. The engine is pretty quiet, you're probably hearing the dyno spin ;)

The last 2 times I put silicon (SFS) hoses for coolant on a car they leaked and required additional tightening of the clamps. Silicone sucks for coolant I would stick to stock. Is always a better fit but doesn't look nice.

I got to the dyno last week, but due to a blown fuse the dyno itself didn't work. So in the meantime I replaced a couple of small things (injector plugs and seals) and went back today. First result was a disappointing 236,5hp at the wheels. But for some reason the AFR's were extremely rich (see the dyno sheet) so I pulled and plugged the FPR hose and power rose to 253hp ATW with lowered AFR. The AFR was still to rich, we estimated the engine would do around 265hp ATW with the right AFR. That's very close to the ITB setup at 263hp ATW, but that run was done when the temps were much higher and I used slightly less quality fuel. So I'm quite satisfied with the result. I still feel some air leak is causing the engine to run to rich, but as I can't find it there could also be something wrong with the AFM. Now it's time to swap the stocker back in and dyno it... Blue is ITB's, green the run with this manifold and red the run with to much fuel. Note how equal the curves are, most likely due to the similar velocity stacks and runner length used.

It's got the vg30det, less complicated single turbo version of the TT

Got the engine up and running. Apart from a gasket leak all went quite well. Requires just a bit of work but for now it runs nice. Should be seeing the dyno soon. Nothing spectacular, just evidence of being in working order;)

Took me a week to figure it out but here's how I eventually did it:biggrin:. The pics explain how it works. The wheel in the middle has a bronze bearing. The cables were designed as brake cables for bikes, even Jenvey uses simple cables like this so no doubt this will work perfect. The cruise control lever can be installed later on opposite to the regular throttle cable, because it normally spins freely on the throttle shaft, it needs it's own bearing and spring. Too much works at this point, but worse, the cable kinks as it's not of the right length. I would have to rotate the entire CC unit. Maybe next time. The 90 degree steel bends are filled with teflon liner, the were a very tight fit underneath the manifold. The aluminum wheels were all made by hand. - - - Updated - - - Thanks, if someone's interested I could make more of those pulley brackets:thumbup1:

Starting to get there. Finished the intercooler pipes and the idle hook up welded to the balance pipe. I don't really like the 'bends' within the balance pipe like this but weld elbows this size (25mm) cost 50 euro's for a pair. A bit too much for something not that important. The bends for the intercooler pipes have a short radius. It would have been possible to use a wider radius but this would have looked even stranger and not improve the airflow. I'm now in the process of hooking up the 2 TB's, it's a lot more difficult than I had expected. But I will get there, hope by tomorrow.

I finished the other side manifold an now in the process of linking the TB's, and fitting the AAC unit along with a balance tube. Just like the ITB manifold, the weight saving is substantial. I estimate the complete system will remove around 7kg from the engine. The air regulator will be removed as well, useless device. The AAC can easily hook up for the cold start. it looks so small doesn't it? I didn't want to remove the timing belt again due to the lower manifold swap, so I made a special fixture to hold the timing belt pulley in place. It braces itself to the underside of the intake pulleys and pushed down in a triangular shape upon the belt pulley. By applying the right amount of pressure on the pulley, it worked so well I could remove and install the bolt that holds the pulley by hand. It didn't move a millimeter.

Like I said in the ITB's project, there's another intake manifold coming up. As the 300zx is still in my driveway, it will serve again as a test and dyno mule. With the ITB manifold everything was designed for maximum performance explaining the large plenums and custom intercooler pipes. This time the manifold should be easier to fit by making use of more OEM parts, and being much cheaper to fabricate. Modifying the valve covers, fuel rails and ignition coil brackets is still required though. The length of the intake runners is just as long as the ITB manifold, around 39cm which is a good value for what most vg30's are tuned to. This manifold has smaller plenums that hook up to OEM throttle bodies. The plenum volume is roughly 1,5 liters per side, only slightly larger than stock. However, due to the improved design and more central TB location going any bigger won't really do any good. I milled the TB flanges to 58mm in case it's being tested on a car with enlarged TB's. The TB's will be linked by cables requiring some work to them. I'll have to fit the manifold to the car and check fit and clearance for the lever setup in the final stages. The TB's sit at a 45 degree angle and face downwards about 10 degrees. By using just a 60mm 45 degree hose it can be directly hooked up to a hard pipe kit. For a 'soft' hose connection, a short 45 degree aluminum bend can be fabricated. So far it has come to what you see in the pics below. The Border fuel kit fits without problems after I mill the excess material away. The stock fuel rails require new fittings fabricated at the ends, and removal of the original hose fittings. Welding the fuel rails is a bad idea I've learned so they must be hard soldered. This project should go much faster and the modifications to the coils, fuel rails and valve covers are already done. The welds may look a bit odd around the plenum cause of polishing residue. This manifold is also going to fit with top feeds. The bolts that hold the velocity stacks in place first bolt into the plenum floor and are again secured once the manifold is welded shut. The heat from welding destroys any sealant put around the bolts so after it is fully welded additional nuts are screwed up and sealed against them. -Rutger

In theory, the plenum chambers can be made from carbon fibre. However, the chambers will have to be bolted to the aluminum flanges were the velocity stacks sit on. Highly complicated to fabricate for just 1kg weight reduction

Had to figure out how to legally drive the car to the dyno and I got it all worked out this week. So I went to the dyno today. Last week it ran perfect, but it started hesitating very bad yesterday so I was worried all was gonna fail. The fuel system was good, and the timing was set correctly at 15 degrees. I didn't knew anymore where to start. So I went with some of the basics, refitted a poorly grounded harness cable and cleaned the AFM and CAS harnesses. Then, all of a sudden it pulled correctly again. Now I haven't driven this car in anger before the manifold swap, but it does feel like the standard mapping is not suited to this manifold. If I quickly depress the throttle after a gear shift, there's no response. It also feels somewhat nervous and sensitive to throttle changes, a bit like my brother's Gti-r with the OEM ITB setup. This system really needs a map 'written' for it. Anyway, on the dyno all went well. The car pulled 263hp/349nm uncorrected at the rear wheels, on a warm day (29 degrees C) and the coldpipes from the intercoolers got very hot as the 2 coolers they had were not that powerful. I estimate the inlet temp was around 45 degrees C. During the other pulls the power went down as the engine heated up even worse and the operator couldn't get a good pulse from the ignition system, the output was therefore measured in speed not rpm's. The blue line is the first pull. The torque values are incorrect, they had some trouble getting the dyno system to correctly convert. Explains the weird 800+nm spike. Realistically, it's about 350nm at the wheels. Now I'm not directly converting the car back to stock, there's another type of manifold that I want to try on the dyno. Roughly the same as this one, but with the stock TB's. Will make a different topic for that.