GT74 High Compression Six Speed

http://www.wallaceracing.com/dynamic-cr.php

 

 

Part of the tuning is 'black magic' brigade are we? You must be extra speshul to understand this stuff.

nope.. :rolleyes:

Thanks for your contribution

My thoughts exactly

DCR calcs are a bit of a secret.... there is always tons of talk, but no noones that actually knows will say anything.. me included

Great post - thanks.

Got my pipe back from Martin, he has made up and welded on, two bosses for my water injection jets.

The end of one jet just a mm below the inner surface of the pipe wall.

The pipe fitted back in place and water/meth feed plumbed in. The other boss is blocked of for now while I test the system with just one jet.

I spent a few hours today sorting out the final adjustments to my water methanol injection system.

I made a simple pressure testing kit, using a bike track pump various bits of hose and a multimeter connected to the pressure switch.

I connected the free hose end to my boost gauge, so I could set the system to coincide with boost readings on my gauge. Once the trigger boost was set, I tested the system to make sure everything was working correctly, when trigger boost was reached. I did find that the boost switch had about a 0.3 bar difference between trigger pressure and shut off pressure.

The spray pattern looks fine and was made of very small water particles that were easy diverted from course by blowing gently near in to the flow stream. When the engine is on boost the speed of the inducted air will rapidly carry the water/ meth mix and do a good job of cooling the charge and the inside of the combustion chamber.

Wow, you do some amazing work - I'm extremely impressed with the amount of hands on work you have done with this beast... VERY nice work!

One serious piece of advice, if you are swapping a gear box or have the engine out, do your self a huge favour and refurbish the starter at the same time. For £20 and 15 minutes you will save yourself much time and aggravation in the future. Your starter will fail. I wish I had done it, mine packed up today, just as I was going to test my Water/Meth injection.

I read up on the helpful refurbishing the starter solenoid thread in Tech. Very helpful and informative. The multi bar long range stuff for accessing the top bolt put me right off. In the end I got the top bolt undone from directly underneath, much easier than trying to undo it from almost two feet away. I will post my pics in the tech thread as an alternative approach.

I think I would go as far as to say this ought to be essential to do, in any engine or box out project. My solenoid contacts have done well lasting 15 years.

I can vouch for the above advice. I did just the above and did not change or refurbish the starter and had to do it afterwards. Its a complete pain in the arse

Hit massive over boost today 2.2 bar, may be less due to gauge inaccuracies. Boost cut triggered so no harm done. Took a while to trace it to a small hole in one of the HKS braided lines supplied with my waste gate. A real mystery as to what caused it, the hose is wrapped in a fibre jacket and not in a hot area. There was no sign of damage to the fibre jacket, so the hole must have been made from inside to out side.

After a closer inspection of the suspect hose, I found what can only be the result of a stray welding spark caused during the build. The spark had melted the stainless braiding and weakened the PTFE inner, a fault waiting to happen.

This could not had happened any other way as since the build the hoses have been sat on top of the brake servo in insulating sleeves.

That looks like a classic electric short to ground via the braid.

Interesting Chris; I don't know how, as there was no battery in the car for most of the build. I'll have a look round the brake servo to see if there is evidence of spark damage.

I have had enough of chasing air locks in the water system. I picked up a bleed valve from Audi and put it in the high point of my water system. Problem solved, just need some better quality hose clips.

Now that is a great idea Phil!

Will have to copy that as I have had the same trouble with mine trying to get the air locks bled out. It does seem to have reduced the more the car gets driven, but it's still not how it should be

Yep drove me mad, chasing the little bubbles, I think air swells by something like 273 times it's size when the system is hot. When I cut into the hose this afternoon, the pipe had air in the top half of the pipe. I don't think my system has been air free since my build.

The bleed valve is from an A8, it is high quality with metal lining so very strong. The vent hole is wide enough to pour coolant into the system, or just loosen the valve with a socket when hot and let the system refill from the expansion bottle.

When I cut into the hose this afternoon, the pipe had air in the top half of the pipe. I don't think my system has been air free since my build.

This is the same issue I have, even after using the car today, when releasing the pipe in your pics much more than half of it was air. I never had this issue on my old single car but then again never emptied the entire coolant system on it.

Some people have suggested using a powered fill, but don't think that works on the 2JZ, even with the engine running.

How was the cabin heater before and after? Do you get more heat now?

My engine was fully built, so totally dry when connected up to the rest of the water system. I have had slight, but annoying water issues since putting the car back on the road. I did all the recommended procedures to get out the air, but they did not work. My initial solution was to run duel expansion bottles to absorb the extra expansion. I thought the only long term solution would be a bleed valve, but finding the right one was difficult. The one from the Audi, is certainly a quality item.

With the system hot, I let out a very small amount of air from the vent today, my first expansion bottle never reached full, so it appears to have done the job.

Can't comment on the heater as I don't use it. I would certainly recommend adding a bleed valve especially if your water system is no longer stock.

Checked my water system today and the expansion bottle level has settled at about a cm above the full mark, probably the extra coolant I feed in to the open bleed valve to replace the air in the system. With the engine hot, the coolant the level in the my expansion bottle stays below the overflow point. Pretty conclusive proof the bleed valve was the thing to do.

Good work Phil

I decided to change my UK front brakes. I was beginning to lose confidence in them, as several times they have left me praying that I could scrub off enough speed. One too many heart stopping moments convinced me to change. I opted for KSport 8 pots with 356 discs, the biggest I can fit under my wheels.

First I checked the cleaned up the hubs ready to check run out. Really important to do this properly as any excess not checked will be dramatically amplified at the disc edge causing poor, pulsing MOT failing brakes. It is advisable to do these checks well before fitting new brakes, as any excess hub run out can only be cured by replacing the hub. I checked mine a few weeks back, when I put my UK's up for sale. I did just a quick second check to confirm everything was OK before test fitting the new discs. Hubs are checked on the matting face and round the edge.

All results good, so on to the next step.

The discs have to be checked for run out on each of the 5 possible mounting positions. All five wheel nut need to be tightened to specified torque before each run out check. Match marks are essential and it is a good idea to record the results, so it is easy to pick the best run out configuration.

Discs are checked for braking face run out and edge run out.

All figures well in spec on both sides of the car.

The calliper needed to be checked for centre alignment with the centre line running round the disc. KSport proved a packet of shims to enable adjustment. The MKIV kit is well made and once torqued up mine was perfect, without shims on both side of the car.

With the fitting complete, pads and retainers fitted, no anti- squeal shims, braided line fitted, I changed the brake fluid in the whole system, approximately 1.5L, bleeding furthest cylinder from the ABS unit first. After the wheels were torqued up, I took the car for a drive to start the bedding in miles. As soon as I pressed the pedal on the move, there was a noticeable improvement in braking feel and force, compared to the UK's used earlier in the day. Even on totally un-bedded pads, the brakes felt more positive and progressive in feel. I have a few more miles to do before using them in anger. Initial impressions are very favourable.

Did a little 120 mile trip today to finish bedding in the KSports. Towards the end of the journey, I gave the brakes some real hard stops. Very impressed, the UK brakes never pulled up hard as these. Good feel too, a big improvement.

The little boost issue I had has turned out worse than originally thought. I got a new hose made up, connected and carried out a test run. First WOT saw the boost swing over 1.5bar. Fortunately my WI triggers at 1.3 so I would have had plenty of water in the intake to keep things cool. I carried out a couple of checks on Saturday and today and checked with Chris Wilson and it sounds like my waste gate shaft seal has started leaking. What were the chances of both the shaft and a hose leaking at the same time.

I have spoken with other members with experience of big HKS waste gates and there seems to be a pattern emerging. Needless to say I am pretty pissed as it has only done 5000 miles. So I am looking at other waste gates. Anyway until I can get another one or two gates fitted and my exhaust system altered, I am stuck with 0.9 bar spring pressure for the short term.

Any suggestions or recommendation would be appreciated.

That is unfortunate Phil.

I would suggest to go with a Tial wastegate. Very reliable and don't suffer like the HKS seem to be doing.

I've seen at least 3 having a similar issue to yours, all were the version 1 race wastegate.

The V2 race gate they done was a little more reliable as a whole, although I have only had personal experience with one of them.

If I still had it I would have sent it up for you to use in the meantime.

If your looking to change the gate setup I would consider twin 44 Tials, or if you want to stay single wastegate a 60mm Tial.

On Cody's car a 100whp gain was seen from changing to twin 44's from a 60mm.

I've attached a pic on how his sits atm

On Cody's car a 100whp gain was seen from changing to twin 44's from a 60mm.

How?

How?

Better boost control, and he was able to reach his target boost, which the 60mm wasn't allowing

It now sits with a range of 24psi base and 42 max.

It made 1385 on boost with the twins and was 1292 with the single iirc and could only get to a 36 psi maximum.