Thanks. It's grat to drive...although not as quick as some of your monsters, but quick. I hope the gear box holds up, the clutch sure didn't.....
Great to see you finally got to do a pull on the dyno. Very impressive numbers. Have you thought about getting the throttle body ported? One of the guys here had Kirmit port his throttle body out, and he was very happy with the results. Also, what exhaust set up are you running?
Thanks Ernie. I think the stock throttle body is a 65mm, I'm running a twin 62, so almost double the size. I also have a 65mm oval that flows about 30% more than the twin 62...it's the one I had on in the beginning but when I deid the rework and moved the blower, the thottle cable won't reach any more....and I really wanted the car running so I through on the smaller one that did work. In the next couple weeks (which on my schedule means hopefully before winter) I'll fix the big one and give it a try...I think it should gain me 1 or 2 more psi...it could be 20-30 hp. When I get a better dyno run I'll post it. I have a borla exhaust that I got for ferraiads.com a few months ago. It sounds pretty good, but I think it's still a bit restrictive. I guess what I really need is bigger diameter heads and 2 really big mufflers....but that is another project.
I just thought of a good use for my slow down light. With the cat empty is can't overheat, so the light is not needed....but I can connect it to the ECU and have it light if the air temperature gets too high...that way I'll know if something goes wrong with the intercooler or something. Unlike a turbo system which is set a a pressure and stays there, a blower always pumps the same amount of air, so if the intercooler goes down (it's water/air, so it has a water pump, wires, relay) the air gets hotter and the boost pressure can go way up....very bad. I have the ECU set to sut off the fuel if the boost gets too high, like a rev limitter, but some warning might be nice.
I'd try CenterForce for a clutch. Tildon is also a possibility. They'll make you a great clutch for a reasonable price. Gearbox's now that's a different problem...
Very impressive numbers. Many people do not realize that most torque is produced between 5600 and 6600 RPM with supercharged cars. In the days we were drag racing this point was proved over and over. We found that engine life was extended when we limited our top rpm to about 2000 rpm over that torque high point. Anything past that point simply broke parts. And I will take relability ANYDAY over a few extra ponies. With a motor of your nature it is not something parts are easily found once the block has a huge hole in it. Yes make the light do something else. This is not an easy project, so keep the midnight oil burning in the garage. Speaking of oil, what are you using in the engine? Tried Mobil 1 or Redline or Amsoil? Amsoil Gear Oil was the only rear end oil that would not turn our hypoid gears BLUE after 25 laps. Not even a cooler would help. Remember this was 20 years ago so we tried many things and found that the quality of the oil was a great factor in controlling heat in all drivetrain parts. More pics would be nice.
OK. I got my crank sensor fixed and made another run with a couple more adjustments The new numbers are: hp=425 @7050 torque = 349 @5400-6000
Simply beautiful graph with awesome results. How would you comment on both on and off throttle response? Any axle tramp? Again, great job!
Double WOW -- Sometimes I think Mark is completely out of his mind, but I'm beginning to think he could be the only sane one among us ...
That torque curve is AWESOME for a 3.0 liter engine!!! I realize it's supercharged, but still, that is incredibly flat and "gradual".... not peaky at all!
I think your right....you can see the boost climbing fast at the end of the pull. I've used mobil 1, right now it has castrol synntec in it. the trans has redline synthetic gear lube I think....I put it in last fall. I have a oil/water heat exchanger on the engine oil, but nothing for the trans is on it's own....I don't run it at the track though, so I don't think heat will be a problem. Id di you look at the 3 threads I post towards the beginning? There are a lot of pics in them of the construction.
65-75°C, that's high, the 308 must be a very detonation tolerant engine. If my turbo Toyotas get that high I have the ECU programmed to dump fuel, retard timing and inject more water or else I'm likely to have to rebuild the motor. If you could drop the intake temps to around 50°C then there's probably an extra 30-40HP available. From what I can see from the photos a cold air box, with a feed from the side vents, should help lower the intake temp, and if you don't mind cutting holes in to engine lid and the bottom of the boot/trunk then a good sized Air/Air Intercooler can be mounted there, which is what a lot of high HP MR2's do with good results, though I don't like it myself. Water/Alcohol injection would also help, and will allow more ignition advance. Do you run a reservior for the I/C or is the capacity limited by the core/plumbing volumes. Most Water/Air setups that I'm familiar with run lower temps than Air/Air until they heatsoak, if you don't mind the extra weight then you can delay the onset of heatsoak and improve cooling by running a 2-3 gallon tank and lowering the pump volume so the water spends more time in the cooling matrix. What's the engine bay temp like, I've been considering putting twin turbos on my 308QV but I keep hearing about high temps in the engine bay, which makes me think a supercharger might be a better option, though I'd prefer the turbo route as I have a few spare ones just the right size. From the latest graphs you've posted it looks like there's an increase in volumetric efficiency around 4500RPM which accounts for the dropping boost and increasing torque. Looks like a restriction develops after 6700RPM, probably exhaust system, but maybe valve area, easy to find out though by running an pressure sensor in the exhaust system. Have you got adjustable cam gears? If so have you played with cam timing/phasing much? BTW I really like the flat torque curve must make for good driveability with a little more tuning & refinement you should easily see 500HP
Throttle response is quite good, but I still have a little more tuning to do...notice the jump lean when I open the throttle at the start of the run. That goes away if I roll it on....I need to add the equivalent of throttle pump, which in EFI is acceleratio enrichment % and substain time. I'm not sure what you mean by axle tramp....but it sounds like I don't want it...
You are so right that more cooling would be better....but I just couldn't bring myself to cut any holes. So I'm stuck with water/air....but that means 2 heat exchanges instead of 1 like an air/air, and that means add 20C to the intake temp. I also probably screwed up a little putting the IC core in the intake because the size is limited, but it is very neat and makes a clean engine bay...I know those things shouldn't matter if I truely want to worship the great of hp, but it's a thing with me, I like to look neat and stock.....I didn't add a big tank or water injection thinking I really wanted a system that worked at steady state, not just short bursts then need to cool down or refill the water tank....honestly, remembering to check fluids is not something I'm very good at and I was a little afraid I'd forget and overheat something.... There is a plan to add a cold air intake to the vents, which is why I pulled the stock oil cooler out and replaced it with a water/oil heat exchanger....I just need more time, but it's on the list. The engine bay temp seems about the same as it ever did. I guess it must be a hotter, but I don't notice the difference. There is a guy who posts here who had norwood turbo his QV last year, he might have some insight. I think turboqv is his user name, Paul something....my memory is the worst. I guess I know the hp could be higher, but the project goal was originally a 500+ hp engine (although I was hoping to get closer to 600 as the project progressed) with all the drivability of a stock engine. This engine does everything I wanted it to do, I know there are plenty of cars out there that are faster, but that will always be true no matter what I do...oh well. I like to autocross when I have time, and I'm sure I've got enough power to make the car way more of a handful than I will ever be able to master. I think it's abot done. Time to figure out how to get bigger brakes on it.
Forgot these... The cams are very mild in a QV, and the stock hp peak is at 6800 because of it. I have stock cams, so I thing that is what you're seeing on top. I have the cams timed to the euro spec, which would put the torque peak at 5000, so again, I think that is the increase in volumetric efficiency that makes the boost drop a little through there. Basically all the things that make the nice torque curve limit the peak hp as far as I can tell. I know just a little more cam lift and duration , maybe 10 degrees, would add 50 or 60 hp if I could keep the boost pressure up. But the blower is already hitting 15200 rpm, I just can't spin it any faster, so I think the boost would drop and I'd gain nothing...I might be wrong though, it sure wouldn't be the first time....
Great work, nice looking installation! Congatulations! I did see a 308 with a Dyer blower producing 670 HP, he used a traction limiter system to reduce trans problems, by not using ultra-wide tires, he added a little planned slippage (8->} Bill
He used to work with the Ferrari IMSA Team efforts and had a few of the experimental bits left over, like a nice manifold, to make the blower/engine connection, no intercooling. Of course it does not fit inside the stock bonnet, if I remember correctly it was an 871, I don't know what ratio he was spinning it at. He was using the car for hillclimbs. I used to have some pic's of it, but can't find them at the moment. Bill
