Graham Rudd

Ok, so its likely that I'll have to do something about my fueling. So what exactly would I need? I already have an uprated fuel pump. Obviously I will need 6 UK spec injectors and a suitable resistor pack. Anything else? Fuel regulator? Injector rail? I'm guessing no to these, but you're the experts! What is/does an AFC do? Would it be a sensible addition? What if I decide to upgrade to a big single at some point, would it be wise to forego the 550cc route and go bigger? Any advice will be much appreciated, and I promise to stop talking about injectors if someone helps! Thanks, Graham

Ian, I haven't had my fueling checked. In fact your situation is one of the reasons that my mind has turned to my fueling. I'd like to know what the max duty cycle my injectors are running at. What factors will the ECU use to determine the injector pulse width? What I'm trying to get at is this: Could it be possible that the ECU is running the injectors at a duty cycle it believes is correct for the current conditions based on the information its been fed, but it turns out that the duty cycle is too low despite the fact that there is a lot more 'slack' available to the injectors. I guess I'm saying does it boil down to the fact that the 440cc injectors may be adequate for my needs but I need bigger injectors to introduce a cludge factor that works around limitations introduced by the sensors available to the ECU? Hope that makes sense! Cheers Graham (just trying to understand!)

Is the fuel regulator visible in any of the pics I posted a link to? Or is there a giveaway that might tell me if I've got a stock fuel regulator or not? Thanks Graham

Mark, Thats partly the reason for my questioning. I've got Hybrids, ECU, Cams, HKS 'R' Spec FMIC, EVC, Water Injection, Induction kit, Exhaust... yadda yadda.. I figured at some point I'd better sort the fueling out. Would have loved to have just been able to tack 550cc injectors on there.. seems not though. Cheers, Graham

*sigh* So the only real way to go is to get a Motec? Wonder how much that would cost to get all plumbed in properly and mapped correctly? *shudder* We need a money bags volunteer to do the leg work Grahamn

Just to recap though. Will it be true that J-Spec owners with 550cc injectors and no F-CON or VPC or any other 'lets fool the dumb ass ECU' device, will be running 20% richer than stock? Cheers, Graham

Yep, I know I need a pump (got one) and resistor pack. What I really want to know is if its a good idea or not to do. I'd like a complete understanding of whats going to happen first. Just me being pedantic. Graham

Can you explain what a VPC does please Alex? (simpleton terms please) Cheers Graham

Erm.. cheers Adam Well, if what you say is true then would sticking 550cc injectors on a Jap spec car without doing anything else not be a bit cludgy? What would happen if I reduced the voltage from the air flow sensor by 20% then? Sorry about all the questions, I've got my 'just have to know' head on today. Car eh? Bloody mystery to me! Cheers Graham

That doesn't really address the original question though. What about those that haven't got a fuel computer? What happens when you stick the UK injectors on a J-Spec car without doing anything else? I'm assuming the ECU recognises the fact that the mixture is too rich and reduces the pulse width of the injectors. If not then where is the compensation made? In fact, if you're decatted isn't the lambda sensor removed? Just to re-iterate: I'm not having a go at anyone's setup, or doubting that upgrading injectors work. I'm just trying to find out how it all fits together for my own satisfaction. Graham

Can someone explain what effect replacing stock jap injectors with 550cc or bigger ones will actually do, and how it works? I can understand that replacing 440cc injectors with 550cc ones can provide more fuel. What I'm more interested in is what happens when you're just tootling along and don't need a river of fuel? If a 550 injector is open for 1ms, would it spit out more fuel than a 440 open for 1ms? If this is the case then wouldn't the ECU have to be remapped to actually make sensible use of the bigger injectors? Surely it would be running stupidly rich if it wasn't, or will the o2 sensor and the closed loop operation take care of this and adjust the pulse width accordingly? However, if this isn't the case then how do you actually get the ECU to open the injector for a longer period of time? Again wouldn't this involve remapping? (I may have answered my own question in the previous paragraph) Any insight into how it works would be great, I don't doubt the fact that replacing the injectors works fine, I just want to know how and why it works. Many thanks, Graham

Alex, I use SUL + octane booster, 1.9 was down to a hose coming off. I *think* the injectors are stock 440cc, not certain. Gavin, here is a link to the pics I've just taken. http://www.matrixcity.org/supra_bay.html Peter, thanks I'll check all the hoses I can get at tonight. Graham

Ahh.. definately not that then, I don't have a fuel cut limit. In fact I was boosting to 1.9 bar with no problem (bar the obvious) when one of my hoses came off. Graham

Yep, whereabouts shall I point the camera? (Edited by Graham Rudd at 1:59 pm on Mar. 12, 2002)

Gavin, I've no idea if I have the stock fuel regulator or not. Any quick and easy way to tell? Lee, I have a boost gauge, but it doesn't seem to be boost related, more to do going from practically no load on the engine, to giving a bootful. Doesn't happen at speed. AJI, definately not traction control, stock or RL. I don't like the "sounds pretty bad." bit! Graham

Hey Branners, can we set up another topic heading... I suggest naming it "Bradb's inane comments". Graham

If I plant the throttle from quite slow speeds, usually from rolling along in second gear, I seem to get some hesitation as the second turbo kicks in. Its best described as a sort of juddering around the point the car should really take off, as if it wants to go but can't quite manage it. The effect feels pretty much as if you were pumping your foot up and down on the accelerator very rapidly (quicker than you could actually do it in reality). It'll do this for maybe half a second, then suddenly take off as if nothing is wrong. It doesn't always do this, but when it does it feels pretty bad. Does the supra have a throttle body position sensor? If so could it be that mine is a bit iffy? My limited understanding of the subject seems to suggest to me that maybe the fuel isn't being delivered to cope with the sudden intake of air. On the other hand I could be talking complete arse. One thing of note is that I've got a Blitz ECU, could this be the culprit? Cheers Graham

Ahh crap.. sorry Tony, I must have managed to miss your mail I'll definately sort it out tonight. Actually, if you can get a copy from Phil sooner then that would be fine. Graham

I was out in the soop last night, on the way to a friends house and decided to have a quick blast to liven the journey up. Coming off a sharp bend I nailed the throttle only to have the backend decide it wanted to see where we were going! After the initial panic attack I managed to maintain at least some semblance of control and keep the car on the road. Hmmm.. surely this can't be, I have traction control for God's sake! I'm supposed to be invunerable! After a quick experiment on another empty corner I could safely say that something was up with the TC. Well, I got to my mates house and told of my scary experience to which he just replied, "Yeah, some of the guys on the 300 board have had the same thing, they had to re-calibrate or something.". (yep, he's a 300 owner). I've just been out and checked my calibration.. oh dear. It seems my driven and reference wheels had switched places, oh and sides, left had become right. I did a quick calibration run and now everything seems fine again. Question is for how long!? Anway, I thought this was worth mentioning to the group, if ever your TC seems to be acting strangely then this might be the answer. Well, its a gorgeous day outside, a fantastic day for going for a blast, or washing the beast.... so I'm off to work *sob* Have a nice weekend all! Cheers Graham

Not sure if this is relevant or not to your problem, but mine will absolutely not calibrate unless the turn is very tight. A mini roundabout is perfect. Graham

Brian, I've never seen a comm error using Racelogic's software, but I do only get the 4 or 5 seconds of sampling whilst data monitoring. The reason I wrote my own software is due to the sheer unfriendliness of Racelogic's. Graham

Thanks Pete, I'll certainly be in touch when its ready. In fact I need to contact you anyway to pick your brains about a PIC programmer for the 16F877. Cheers Graham

Its been a while since I've done any work on the TC App due to a heavy workload at the minute. However I had a request from someone for a copy of the latest version a couple of days ago so I dug it out last night to check on the current state of progress. This is how it stands: 1. You can view/edit all of the parameters in the RL unit has to offer. 2. The data logging is pretty much finished, by that I mean you can capture data, and watch it being captured in real-time. 3. The data analysis section is working, but I'm not happy with its stability to allow people to run it on their machines just yet, plus it needs some tidying up. What I propose to do is make a conscientious effort to get it finished, or at least in a good state either this, or next weekend and then maybe put it on a web site for download. I originally only wanted to give it out via e-mail so that I could keep track of the people who have it so I could let everyone know if I found a nasty bug, or simply to inform people of an upgrade. The trouble with this is that I'm far to busy at the minute to keep mailing it out. It would be very nice to be able to set a site up whereby people can download the software, a selection of DAT files and be able to submit their e-mail address for contact purposes but I've never ever built a web page, looked at HTML, Java or whatever else could be used in the wierd world of web design. Anyway, I promise, I'll try to get it finished very soon! Graham

Matt, Clacket Lane Services is fine. Graham

I'm in Aldershot.