ArdWrknTrk Posted July 4, 2019 Share Posted July 4, 2019 Well, let's be clear, while my Devon family may be still throwing chippies at the pub screen, and no one is spotting me a pint, some of us were already proudly wearing our number 13 jerseys on this side of the pond! Direct injection: Pitfalls, optimization.. is there a future for this diesel/petrol hybrid? So, many have tried direct injection in street cars. The biggest downfall being EGR leaves horrendous residue on the back of the intake valves. Sometimes the valve won't seal and sometimes the carbon eats the valve guide. When direct injection is used knock is all but eliminated. There is no fuel charge to detonate until it enters the cylinder. Compression ratios can be raised to 14:1. (funny how that's almost stoichometric) Mazda seem to have found a way around the EGR problem by using variable valve timing to trap exhaust in the cylinder instead of routing it all the way around. They claim increases of 15% for both economy and torque. I think this, combined with the latest variable compression technologies might be the last great glory for ICE. Mazda have always been small and scrappy. They are willing to persue things like rotary engines and have been seen as "a driver's car" with models like the Miata and the RX series. https://www.roadandtrack.com/car-culture/a17171105/mazda-skyactiv-x-how-it-works/ Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 4, 2019 Author Share Posted July 4, 2019 Direct injection: Pitfalls, optimization.. is there a future for this diesel/petrol hybrid? So, many have tried direct injection in street cars. The biggest downfall being EGR leaves horrendous residue on the back of the intake valves. Sometimes the valve won't seal and sometimes the carbon eats the valve guide. When direct injection is used knock is all but eliminated. There is no fuel charge to detonate until it enters the cylinder. Compression ratios can be raised to 14:1. (funny how that's almost stoichometric) Mazda seem to have found a way around the EGR problem by using variable valve timing to trap exhaust in the cylinder instead of routing it all the way around. They claim increases of 15% for both economy and torque. I think this, combined with the latest variable compression technologies might be the last great glory for ICE. Mazda have always been small and scrappy. They are willing to persue things like rotary engines and have been seen as "a driver's car" with models like the Miata and the RX series. https://www.roadandtrack.com/car-culture/a17171105/mazda-skyactiv-x-how-it-works/ Good explanation on direct injection. And I agree about Mazda. Had a first-year Miata and it was awesome. Absolutely no problems with it, and loved it. Certainly a driver's car. Link to comment Share on other sites More sharing options...
salans7 Posted July 4, 2019 Share Posted July 4, 2019 Good explanation on direct injection. And I agree about Mazda. Had a first-year Miata and it was awesome. Absolutely no problems with it, and loved it. Certainly a driver's car. I tried to drive a Miata once. When I went to close the door, It pushed my knee into the steering wheel and wouldn't close. I'm too tall for small cars. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 4, 2019 Share Posted July 4, 2019 I tried to drive a Miata once. When I went to close the door, It pushed my knee into the steering wheel and wouldn't close. I'm too tall for small cars. The CX crossovers are supposedly very roomy. .... zoom, zoom Link to comment Share on other sites More sharing options...
salans7 Posted July 4, 2019 Share Posted July 4, 2019 The CX crossovers are supposedly very roomy. .... zoom, zoom My mom has a Mazda 5 and I struggle to fit in that too, even with the seat all the way back. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 4, 2019 Share Posted July 4, 2019 My mom has a Mazda 5 and I struggle to fit in that too, even with the seat all the way back. Wow What's your inseam Shaun? Link to comment Share on other sites More sharing options...
Ray Cecil Posted July 4, 2019 Share Posted July 4, 2019 I tried to drive a Miata once. When I went to close the door, It pushed my knee into the steering wheel and wouldn't close. I'm too tall for small cars. Shaun, I had the exact same experience. Same with Honda S2000. I barely fit in my classic beetles. Link to comment Share on other sites More sharing options...
Ray Cecil Posted July 4, 2019 Share Posted July 4, 2019 Wow What's your inseam Shaun? Mine is 37". My wife says I look like a frog when you pick them up and their legs dangle....all legs, no butt, and short torso. I am 6'4". She is 6'-0". Our kids are rediculously tall. Probably going to be 6'-6"+ Link to comment Share on other sites More sharing options...
salans7 Posted July 4, 2019 Share Posted July 4, 2019 Wow What's your inseam Shaun? Ray and I are in the same boat. Link to comment Share on other sites More sharing options...
Ray Cecil Posted July 4, 2019 Share Posted July 4, 2019 Ray and I are in the same boat. Tractor Supply and Rural King are the only places I can find pants. Im done with cars smaller than a 69 Impala. Im a truck guy from here on out. Link to comment Share on other sites More sharing options...
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