Top Speed & Fuel Economy

[mattsnewcell]

Yea but that does sounds bad mph and bad mpg, i'd take the cat off man open it up and see. My 88 t1 daytona with a-555 would go 125 easy and 30 mpg worst ever was 22 at the srip for a day

[Reaper1]

Rob, I think you're oversetimating the abilites of a CSX-T as far as top speed goes. They aren't intercooled, they use the Mitsu turbo...150hp, or there abouts. That is good for around 135mph or so power limited, not gearing limited. Gearing limited as around 17Xmph with a stock rev limiter(if it had enough power) and the stock A520 tranny.

I do agree that it is running extremely rich for some reason. Check the FPR to make sure it hasn't failed. It could have been eating MAP's due to fuel in the vacuum lines, which would also cause it to run rich no matter what.

I say get it running right before modding it any farther....

[ljbprrfmof]

Reaper, you suggest that I go back to stock injectors first, or check the FPR (fuel pressure regulator?) first? Should I check the cat also? It seems to rev okay, redlines easily when accelorating. I get a little run-on when I shut it off sometimes and other times it seems to be stuck on a high idle, reving around 1700-1800 rpms when I have the clutch in, say at a stop light.

I appreciate everyones help and suggestions.

[Reaper1]

OK...the absolute #1 thing to check with an old TD is the vacuum system!!!! Get that thing straightened out, make sure it doesn't have leaks and all essential things are hooked up and working propperly. I personally have only 6 main lines on my car: [these are on the intake manifold by the FPR]-MAP, FPR, boost gage [these are coming off the back of the intake where the elbow meets the plenum]-WG, BOV, brake booster.

While you're doing that, check the FPR. Fuel in the vacuum lines are a sure bet the FPR is toast. Even if there isn't, make sure the base pressure is correct, and make sure it changes when vacuum is applied to it, as well as boost.

If that checks out, THEN I'd change the injectors....

I'd also suggest taking the TB off and cleaning it. It probably won't do much for fuel economy or performance, but it may improve drivability by clearing out oil and carbon that may be causing the IAS to stick.

If the car doesn't rattle from the exhaust, and doesn't smell like rotten eggs, leave the converter alone for now. When you do an exhaust then you can make your decision as to whether you want to run one or not. IMHO if you use a hi-flow unit there's no reason to not run one besides cost. It's been proven a lot here recently that good cats don't cause much/in any performance loss. Read the latest Grassroots Motorsports magazine. They have a good right-up on it this issue.

[ljbprrfmof]

I ordered my new injectors this morning. We shall see how the car runs this weekend.

I had mentioned the engine idles at 1800 RPM at times. If it also idles aroun 900 at times, does that mean the cam timing is not a problem? I just read a thread regarding a quick check of cam timing to solve an idle of 1800 -2000 RPM.

[janus]

Quote:

Originally Posted by Reaper1 Rob, I think you're oversetimating the abilites of a CSX-T as far as top speed goes. They aren't intercooled, they use the Mitsu turbo...150hp, or there abouts. That is good for around 135mph or so power limited, not gearing limited. Gearing limited as around 17Xmph with a stock rev limiter(if it had enough power) and the stock A520 tranny.

my stock 92 T1 tona was good for about 150-155, but that wasn't even in the rev limiting range.. so seems to have more aerodynamic and power reasons than gearing imho!? dunno which tranny i have, though ^^ but i do know that everything's stock, so you take a guess what 5speed could be in there lol

[ljbprrfmof]

Hey janus is that autobahn cruising? I would be fun to be able to exercise our cars like that here. I bet people would build their TD's differently if we had a focus like that. My only experience with 'high' speed autobahn driving was in a Renault Super 5 22 years ago. For Americans, think LeCar. LOL Topped out at 112 kph. No wonder people would move onto the shoulder when I passed them.

[Reaper1]

I'm not out to start arguments or wars, but I honestly have a VERY hard time beleiving that a car that has 150hp can do the SAME top speed as the same car with 224hp. It just isn't happening without a VERY strog tail wind. Had you said 130mph...I'd have beleived you. My 1990 Daytona topped out at 127mph(indicated)...that's ALL it had. The car put 130hp to the wheels...stock engine was rated for 141hp at the crank. There is NO WAY that happened with a STOCK T1 Daytona.

[janus]

hmm.. maybe the 225 rubber affects my tach? i was pretty sure it's okay, hmm.. anyway, i can try to do it again once i get it back on the road
oh and, 150mph ~ 250kph right? mby the european export version had other gearing ratios?

[The Pope]

Quote:

Originally Posted by Reaper1 I'm not out to start arguments or wars, but I honestly have a VERY hard time beleiving that a car that has 150hp can do the SAME top speed as the same car with 224hp. It just isn't happening without a VERY strog tail wind. Had you said 130mph...I'd have beleived you. My 1990 Daytona topped out at 127mph(indicated)...that's ALL it had. The car put 130hp to the wheels...stock engine was rated for 141hp at the crank. There is NO WAY that happened with a STOCK T1 Daytona.

I think age has a ton to do with it. These cars are old now, many rebuilt go slower than stock and don't run right. Me and my friends and others were in there low 20s in the early 90s, we were willing to top the cars out when they were near new. One friend I was in school with bounced off the rev limiter in his moms new Daytona in 1990. It was a t1 auto trans car and it was bouncing off the rev limiter at 124 MPH. A 1984 log powered Daytona, one of the worst running cars, averaged over 124 MPH for 24 hours on a closed track setting some record at the time. Some log cars just didn't run well, around 130 most were all done, unless you had a Mopar computer. ANY intercooled car can hit the 6,500 RPM rev limiter running right. I hit 150 in a brand new 1992 Spirit R/T at part throttle, wasn't even breathing hard. The 1990 T1 car had an advantage over the early T1 cars, you could buy one with 211 ft lbs of torque. That with a 5 speed can carry them past 140, the reason is that wind is like weight. The more torque you have to over come wind and weight the more work you can get done. 2.5s don't get there very quikly but they keep going faster, again if there isn't anything wrong with them. Lastly other than the cars being old and wore out how long of a distance are you going? A mile? 30 second blast? My old Charger needed 10 miles to milk its way up the last 20 MPH.

Out west there are highways where you can run 100 miles at a time and not see one house or human, a little easier to reach top speed when you can run flat out for many miles.

[dalejrfan800]

Quote:

Originally Posted by ZoskalonMPI I made it to about 105mph in my TBI Daytona until it just coudn't suck any more air. Once I stuck the MPI manifold, I made it to 110mph once before I hut a curve. Hahaha, nothing like doing 130 in my R/T until the pisspants-limiter kicks in. Make an adapter and a 2 foot spacer for your lugs so you could put rear tracker wheels on the front. Then you'd be hauling ass at 300+mph

Alright, I have a 90 Daytona ES, and I got up 130 in it... is that high?

[Reaper1]

OK...my run in my Daytona was done down a 1.5 mile bridge...I started at 80mph at the top...by the bottom that's all she had. I've had it on flat ground and it took around 2 miles to get to 120mph from around 60.

Rob, I KNOW you're smarter than this. Come on. I do understand that air acts as a weight(aka drag), but I also know that it take 4-times the amount of power to double your speed. Also, look at the power band...the torque DROPS like a rock in the upper rpms...there WILL be a power limit to the top end of these cars before you run out of gear in stock form. Figure out the needed power for our cars to run the speed you're saying, then look at the power band and see if it matches. I can pretty much predict that the power isn't there. The simple physics is against these cars going much over 135mph with 150hp. For refference other cars with similar power numbers and shapes top out right around the same range.

I'm simply not buying it.

[Ondonti]

Chris,

Racing downhill with tires that are smaller in diameter then stock helps pretend the speedo said something it shouldn't

[ljbprrfmof]

A stone stock Chrysler Crossfire will do 150 mph from 220 horsepower 3.2 L V-6.
Six speed manual. Just poking my nose into my string here. That is not proven by me. Driving them with the window sticker and dealer plate really does not allow one to probe the full potential of a car. Well, not this one anyways. LOL

[Reaper1]

Brent, were you reffering to my car? If so, I never said anything about the tires. I was running the stock size 205/55/16's on Ninja's when I did that. If anything those are taller than the size trie the car came with as it was origionally a 14" tire car....

If you weren't then I agree!