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Made a few pulls today at 9.4psi using my ePerformance dyno application. I've used this app on a lot of stock vehicles where the engine performance specs are widely published and the results are very consistent. Just below the results are the settings I've used for my car if someone is interested in downloading the app and comparing results, the ambient temp, barometric pressure and humidity will be automatically entered based on current conditions for your location. For convenience here is a link to the product https://www.perfexpert-app.com
The AFR gauge indicated 9.10 on tip in and might explain the dip in the HP graph. I'm using a MAF sensor from a NA car and hoping the fuel curve on SC MAF when installed corrects the rich tip in condition. Not sure if I'd see an HP increase but hoping to smooth out the graph. You'll also notice I got out of it around 4500rpm all three times (did not want to press my luck) and may have left a few ponies on the table. The torque readings the big take away here and the car's desire to pull so hard really took me by surprise (all three times).
Hello Bob, If it helps you and you can make it work, Then we will work out the details. Do you think Columbus had details to work out? Plant that flag and then go looking for gold.
Apparently, Columbus managed to get all that done on October 12th; I'm not as efficient. Looking forward to receiving the SC MAF to see if the SC calibrated MAF will have an improved effect. Thanks for the offer to support another forum member, I appreciate it.
The pulls were in third and converter was locked right? Just asking because the big spike in TQ could be also converter flash related if the converter is not locked up.
Anyways pretty good showing there as even without the spike you are well over the factory spec of 512 Nm or 377 lb.ft @ 3050 rpm for the XJR
Last edited by AnttiM; 10-13-2020 at 11:38 AM.
Reason: typos
The pull was made at 2000 rpm with the selector in second gear. I'm not sure of the exact torque converter stall but believe it was fully "locked up" at the beginning of the pull. From the driver's seat it certainly felt like a tremendous amount of torque. Complete with rear wheel slip and an expanded view of the hood surface and hood ornament. The app also has a 60 mph test from a standing start; not hard to do using the iPhone's velocity sensors and GPS circuitry. A launch from a dead start much harder on the drive train and mounting points than a rolling start. I'm also running 245/50/17 tires with a slightly larger contact patch. Rather than risk breaking something, I might have to be content with, "It's quick for a formerly normally aspirated XJ6"
Below is the result taking from my Excursion last year. The results are within a few percentage points of the factory specs; factory HP for the Excursion is around 295hp but I got out of the pull much earlier the rpm indicated in the factory specs.
I agree and that is the next step. I've removed both both piggyback ECUs I was using to control timing and fuel, first the AEM F/IC-6 and afterward, the Haltech 750. Since I am now relying solely on the factory SC ECU for everything, the only "handle" left for me to play with is boost control. Initially, I told myself I wasn't going to boost beyond 4lbs, then 6lbs, then 8lbs; now I'm at 9.4lbs now with plenty of injector and fuel pressure to go higher. It's like eating Ben and Jerry's, I can't help myself!
I am indeed running the 30lb/hr or 300cc/min injectors. According to the turbo calculator at https://www.borgwarner.com/aftermark...rgers/matchbot I'll need to flow only 248cc/min at 4500rpm to sufficiently fuel 15psi (double the engine's hp rating) with a 12.50 AFR. At my current setting of 9.4psi,all I need is 200cc/min at 4500rpm, I still have a little room to grow. I wasn't aware there were 42lb/hr Bosch type injectors for the jag, if not specifically for the x300, some other jag whose injectors have the same physical dimensions. To be honest, if I needed larger injectors to provide sufficient AFR I would not hesitate to fabricate a custom fuel rail from billet aluminum or SS tubing to support any injector value I required. As it turns out, the 30lb/hr injectors are the perfect size for my intended application and boost levels. Is there better injector technology out there than that used in 1997? Would it be worth it to fabricate a fuel rail that would leverage new injector technology and spray patterns? Maybe... but am I already approaching my engine's mechanical limits?
@Larry Louton - received the SC MAF sensor unit today. I too purchased one of these reman units from Fuel Injection Corp (FIC) several months ago with mixed results. I'm anxious to try the one you sent to see if it performs differently. Thank you for taking the time to send to me.
To be honest, if I needed larger injectors to provide sufficient AFR I would not hesitate to fabricate a custom fuel rail from billet aluminum or SS tubing to support any injector value I required. As it turns out, the 30lb/hr injectors are the perfect size for my intended application and boost levels. Is there better injector technology out there than that used in 1997? Would it be worth it to fabricate a fuel rail that would leverage new injector technology and spray patterns? Maybe... but am I already approaching my engine's mechanical limits?
Thanks for the question and discussion.
Lucas was the inventor of the disc type injector which doesn’t click or tick. Delphi and others also licensed it and they were used in a lot of different cars. A 30lb lucas disc injector for the Honda B motor is readily available for $25 on ebay, just have no idea if it fits in our rail. 42lb lucas disc injectors are available for the TPI SBC and Ford 302 EFI.
In land rovers the 19lb lucas injectors spray fuel pretty much in a straight line which is their main flaw, dunno if jags. Bosch Gen III pintle injectors for are a common upgrade with very good atomization at the cost of noise and also generally run a little richer.
Larry- I've been "knocking on wood" all evening after reading your comment, "when is the transmission going to give in?" I hope never and also hoping that since I've serviced it regularly since 1999 the odds for its survival has been increased. From what I've read the trannies and diffs are pretty solid for this year jag and will hold up to moderate power levels if serviced regularly. Having said that, I'm on my second diff (the one I rebuilt myself only lasted 6 months) and I have rebuilt the drive and propeller shafts at least twice. A long, long time ago, I welded v-band flanges throughout my exhaust system so I could easily disconnect and remove exhaust components to service the drive shaft, access fuel filter etc. Thanks for your interest in my project and I hope yours will be back on the road soon. I also hope to test your MAF sensor tomorrow evening to see if your FIC reman performs better than my FIC reman. Have a good evening.
The XJR MAF maxes out at 284g/min of airflow, which in my car is about 4000-4500rpm wide-open throttle. I have larger supercharger drive pulley —. see graphs I did on the link to attached thread.
with your impressive turbo numbers I would
imagine you are maxing out the MAF at even lower revs.
‘Dr Greg’ in Aussie did custom MAF for his modified supercharged XJR, which had about 600 bhp. I don’t k ow the details, but you might be able to track him down. https://www.jaguarforums.com/forum/x...adings-202998/
Andy Stodart has previously stated, and I paraphrase, that the XJR fuel map is rich, so exceeding MAF limit will lean out the mixture which should be OK for short bursts..
@xalty Thanks for sharing the video and after watching, wonder if a modern injector with an improve spray pattern compared to the 2-hole or 3-hole Lucas disc injector would not improve the car's drivability? I wasn't kidding when I stated previously, it would not be difficult to fabricate a fuel rail and possible intake manifold port adapters to work with a modern injector. I concur on the noise, the jag's injectors are very quiet compared to my Excursion that has 10 very noisy injectors; not has noisy as a diesel by very loud for a gas engine.
Larry- I've been "knocking on wood" all evening after reading your comment, "when is the transmission going to give in?" I hope never and also hoping that since I've serviced it regularly since 1999 the odds for its survival has been increased.
666 lb/ft on a ZF 4-24 with just a cooler and a hi stall torque converter, these aren’t super weak. One of the owners of these is still active on the BMW 8 series forums and you can probably reach out to him.
Originally Posted by bsparkman
@xalty Thanks for sharing the video and after watching, wonder if a modern injector with an improve spray pattern compared to the 2-hole or 3-hole Lucas disc injector would not improve the car's drivability? I wasn't kidding when I stated previously, it would not be difficult to fabricate a fuel rail and possible intake manifold port adapters to work with a modern injector. I concur on the noise, the jag's injectors are very quiet compared to my Excursion that has 10 very noisy injectors; not has noisy as a diesel by very loud for a gas engine.
Have a good evening.
Perhaps, but more importantly if one that fits between the rails is available it’d be a cheap substitute for relatively expensive injectors. Of course upgrading to something larger is going to need a remap from Andy or whoever else is familiar with the GEMS.
@AL NZ Thanks for the information. I start to generate boost at 2000 rpm and my AFR instantly falls to around 12.5 and at full boost my AFR measured at the turbo down pipe has measured as low as 10.50 I would prefer my AFR only drop to 12.50 at full boost. At the current boost pressure of 9.4 psi, a 12.50 AFR should be plenty safe on 93 octane pump gas and low IATs. I'm also thinking I could experiment with different MAFs from a larger engine; at 10 psi, I estimate I'd need a MAF that would flow around 500-550 cfm at 4500 rpm, probably 3.5 - 4 inches in diameter. Or, I could just turn it down to match the boost pressures of the XJR and AFRs would probably fall back in line.