Nathan

I must admit I've never come accross any problems with VVT-is and HKS induction kits, as seems to be confirmed by others on this list. The only help I can give is be careful with the MAF sensor. They are not known to be tempramental like Scoobies but that is honestly the only thing I can think of, or maybe a wire going to it. Failing that, the other option is to get it on a rolling road, try and get it to fluff and diagnose exactly why it's doing it. Best regards, Nathan TDI PLC

You probably WILL see a drop in EGT at 1 bar with water activated but the fact remains that it won't really serve any useful data. It might be interesting to see how much power it loses if anything but the bottom line is that you won't really be doing anything other than satisfying your own curiosity and knowing that it does indeed operate. The exercise is to see what EGT's the car hits under full load without water and only use it IF you need to bring them down. Any other instance doesn't seem necessary to me. As for the ECU advancing timing when the WI injection starts I very much doubt if that will happen as you are unlikely to be detting at 1 bar anyway so the ignition shouldn't be pulling back any more than the stock map. If it is then I'd say you have a fuelling problem. I fully understand that you want to see how effective the WI is at reducing EGT but what it does at 1 bar could bear zero relation to what it does at 1.2+ bar when the injectors are maxed and shes starting to take rapid deep breaths.... Cheers, Nathan TDI PLC

Thats what the Alex Holdroyds of this world are for.... Your injectors won't even be really working at that kind of load. The incline bit is good but at 70mph in 6th I'd wager that your duty cycles are pretty low (or they should be). An EGT is only valid when the injectors are at their max cycle, because it's usually lack of fuel that sends the EGT's up. In short, if you're hitting 950 on the test in question theres no way your EGT's would be less at 160mph/6K. Not unless your midrange is as lean as hell anyway. Sounds too complicated and difficult to measure properly to me. All you need is two (careful) flat-out runs. On with the WI activated and one without. I very much doubt if your EGT's are a problem at 1 bar so seeing what it does at that boost level is immaterial IMO. Cheers, Nathan TDI PLC

Ahh......! I Didn't know that........ What temps are you hitting flat out at the moment then? The only real way to check it is under full load at high rpm. Most rolling roads top out at 120mph-ish and that isn't really enough. The engine won't be working hard enough for a long enough time period. You've really got to cane them to get a true figure. Go to your own private test track, get her in 6th (or 4th) at around 160mph or 6K rpm and see what you get. Or even a top speed challenge day thingy. Flash readings on dynos are useless. Cheers, Nathan TDI PLC

The problem is that no RR I know of measures EGT, and that is the main area you need to be monitoring in the case of the MK4, as the ECU can kill det in all but the most extreme cases but the EGT's can still go through the roof (usually as a result of pulling the ignition back which increases EGT yada yada....) I've seen them hitting 1150 deg C with no det whatsoever. As you've probably guessed, I very much like EGT gauges Cheers, Nathan TDI PLC

Hi Martin, It's advised to go for 8~15% of the total max theoretical fuel flow, starting at the lower end and only going up if EGT's and/or det demand it. The ERL jet sizes give the following flow based on their race pump as has been supplied with their ‘regular’ kits for a while now. These are APPROXIMATE flow rates only: 0.5mm = 190cc per min 0.6mm = 230cc per min 0.7mm = 260cc per min 0.8mm = 290cc per min 0.9mm = 320cc per min 1.0mm = 340cc per min So, for a Jap spec it would be: 6x 440cc = 2640cc theoretical max fuel flow per min. 8% of that = 211.20cc. That is the jet flow you would start with given the choice, but you can’t get the size so I would go for the 0.6mm. A 0.7mm would be a good starting point for a car using 6x 550cc injectors ie stock UK or uprated Jap spec. Taking the other end of the scale, my old car at 8x 550cc would suggest a 1mm jet at least but after testing I found that a .7mm was all I needed. Theory often falls apart in the real world so testing is essential. The last thing you want to do is run a bigger jet than necessary as it will kill power. As I’ve said before, using WI on cars that aren’t detting or having EGT problems is pointless anyway IMO. Regards, Nathan TDI PLC

It's not critical. If they are too long you can always cut them down. Take a wheel off and get an idea of how long the original ones are. Add at least 5mm and bingo. Try Demon Tweeks for the parts. Although expensive, they have a huge range of spacers/nuts/studs. Cheers, Nathan TDI PLC

No in the normal way it doesn't, but it may be possible. The problem is that most NOS and fuel jets are nothing more than a small tube. Their flow is mechanically controlled via solonoids. The injectors have no electrical signal whatsoever. The only way around it would be to stop the solonoids seeing a power signal. Theres absolutley no way I'd want to see NOS and fuel being injected on a car whilst RLTC is activated. Could be devastating. A customer of ours fiddled with an install we done and manged to activate it whilst the engine wasn't running. He had a NOS ignition inside the inlet manifold and promptly blew every single boost and vacuum pipes to pieces. He was v. lucky he didn't blow the manifold apart or bend the throttle plate like a banana. You may be able, if you set the NOS trigger point to be at a high boost level, to get away with it. Most turbo cars, whilst running an activated RLTC will not make over 1 bar. If your NOS was set at say 1.2 you might be alright. But you might not. Look into it carefully, and plan it out. Just don't let some divvy tuner just slap it all on there. Regards, Nathan TDI PLC

IMO I think you are playing with fire. I wouldn't run 5mm spacers on the stock studs. The Mk4 studs are unusually short compared to other cars and simply don't give you enough leeway. I ran 3mm spacers on mine for a short time, and even then I wasn't entirely happy doing it- I think there was something like 5 turns on the nuts which isn't enough. I ended up running 12mm CNC-milled spacers which actually bolted to the original hubs and carried their own studs. Very safe, but also very expensive and AFAIK are only available from Japan. Also, because of the design, you can only get them in fairly big widths which might make them unavailable for your use. The only other option is to pull the hubs off and fit longer studs. A few of our customers have done this. In fact, one did it to run 3mm spacers. Regards, Nathan TDI PLC

Pete, No war of words! It wasn't a case of getting words mixed up. I just wanted to clarify a very important area. I have been getting the impression for quite a while that people feel that the HKS FCD removes the fuel cut point altogether, thus making it a 'non-safe' option compared to others (in an overboost situation). I had no idea where this suggestion had been coming from and to be honest wasn't too bothered anyway but this thread came up and gave me the opportunity to clear it up. It had nothing to do with scaling V clamping, who should fit what FCD or any war of words whatsoever. The HKS FCD DOES NOT remove overboost protection. Thats all I wanted to get accross. More importantly, an adjustable one at that, by the look of it..... Glad the Greddy issue has been cleared up too. Mid'lifecry'sis, personally I'd use what you have. Regards, Nathan TDI PLC

And one exception not to be sniffed at either...... Theres been a few hitting 1.4 and even at that you are dicing IMO. Throw in a worn jap pump, manky stock IC and a full bore run and even the normally blowup-friendly stock ECU will have it's work cut out. Even if it can haul the ignition back enough to stop det the EGT's could take a piston out. All I'm saying is, be careful. It's the owners that know very little about their cars and how they work who are the most suceptible. Graham was one of them. Regards, Nathan TDI PLC

Hi Pete, I'm not sure I follow here. The HKS unit, being adjustable, means that you can 'move around' the fuel cut point. So you CAN raise it, but it doesn't just go away. You still get fuel cut protection. I've got the impression from you before that the HKS unit removes the fuel cut altogether, but it doesn't, so still provides overboost protection. Does that make sense? The only difference I was aware of with your unit was that it was a clamper (like the Greddy unit) rather than a scaler like the HKS unit. Other than that I thought they did exactly the same thing. Cheers, Nathan TDI PLC

Hi, Forgetting what you have been told for a second, can you have a look at the unit and see if there looks like there is any way of adjusting it. Any little pots or screws, maybe with the word 'cut' somewhere? It will just be a single adjustment, thats all. Have a look in the instructions....OK, they might be in Japanese but they will usually show diagrams.....anything in there relating to an adjuster inside the box maybe? I'd be really surprised if this was a fixed unit. It would then be vehicle specific- unusual for a product of this nature. The HKS/TRL etc. units have adjustment not only to give the user whatever fuel cut point they want but also because they can be used on other cars where say 1 bar would be the limit. I don't want to see you buying another unit if you don't need to! Cheers, Nathan TDI PLC

Thats what I was wondering.....! Does the Greddy unit not have an adjustable fuel cut point? Regards, Nathan. TDI PLC

Martin: Graham Rudd's car was hitting 1.6 bar+ with both his cats out. He would have undoubtably holed a piston if left in that state. ad500: Is your car quite a late model? Regards, Nathan. TDI PLC

Hi Stu, I understand why dragsters use low pressures and high sidewalls. What I don't understand is why BTCC cars run a totally different setup to F1 cars, when both require the same criterias: lateral grip and straight-line power transfer. Sorry...bit of a thread hi-jack going on here Cheers, Nathan TDI PLC

IMO 'whining' isn't usually a problem. Agricultural, clunky, noisy shifting yes, but not whining. I honestly don't think it will be a problem anyway, but it's not 'normal'. Not sure if that makes you feel better or not..... Cheers, Nathan TDI PLC

Exactly. I know it's not much help but my money is on an installation/wiring problem. I can understand RL being cagey on sending you out another unit FOC; there are more than a few poor TC installations going around these days. If your installation checked out OK only then would I consider the box being at fault, or even maybe the pot in the control box. Regards, Nathan TDI PLC

Yep, I'd say do away with the 2nd cat too. We've fitted quite a few HKS Hiper Mufflers with the optional frontpipes to N/A's. The other thing to watch out for with 1st de-cat pipes is that most don't have the flexible section in them like the original. I've seen quite a few cracked ones as a result. The sensor would deffo need to go back in any pipe that replaced the original. Cheers, Nathan. TDI PLC

Is that why F1 cars use massive sidewalls Chris? Then again, if true, why do BTCC use rubber bands with massive wheels? I can vouch for anything Pirelli with the name 'Corsa' on it. Used to use those on my bike and boy did they stick. Only got 1700 miles out of them though :-( Cheers, Nathan TDI PLC

Bizarre. RLTC shouldn't be a problem on the RR. Are you sure it wasn't the OE system cutting in? Regards, Nathan TDI PLC

Agreed. The MR2 Mk1 turbo conversion we did used a pair of custom-built independant chargecooler rads in the front bumper fog-light apertures. The water was pumped front to back (losing even more heat) and the exchanger was mounted in the rear. The owner wanted the car to look very stealth. It was. Cheers, Nathan TDI PLC

Err.....yes. You sent a mail to TDI.....Mark then fowarded it to me as I generally look after the Mk4 guys and now you have posted it here too. I don't mind answering here but the kind of reply necessary would be heavily TDI biased and I don't really want to do full-on non-group business openly on this BBS. Neither would it be fair to others. To save any future confusion, it might be wise for you to mail me directly at [email protected] I will answer your mail offlist. Regards, Nathan TDI PLC

With all due respect to Martin, Chris and anyone else who has had problems with VVt-i's, I really cannot accept this statement. Theres nothing we have come accross that has been a struggle and IMO the VVt-i actually has better potential, if only for the ability to use some pretty wild cam combinations and yet still drive like a stock car. You CAN have your cake and eat it with a VVT-i. Please, I'm not having a dig at anyone, but I just don't want people to get the impression that the VVT-i is a harder car to work with, or inferior in any way to the ealier cars. Regards, Nathan TDI PLC.

What leads?! I must admit it does sound like quite a bit of work at the same time....still, no excuse for getting the car back like that....unless you didn't want to pay to get it sorted...assuming it wasn't a fitter error of course. Regards, Nathan TDI PLC