Why is my mph so low?

[Momar]

I went to the track for the second time since I got the car tonight. Here is a thread that kind of sumarizes the first time to the track. http://www.turbobuick.com/forums/showthread.php?t=154170

My best run was a 1.933 60 ft, 8.6 @79.48 in the 1/8, and 13.579 @ 97.93 in the quarter. Anyway, my mph didnt really change much, but I have installed the stall converter since then, and think that is what made most of the difference in time. I have also installed new valve springs, and series 2 coil pack and coils(the ignition module went bad days after my last trip to the track) since I had it to the track last. I was hoping that one of those would be the reason why it seems to fall of some up high.

The one problem I know I have, is that the one of the flanges on my crossover pipe is messed up a little, and wont seal properly. I plan to fix that in the near future. Could that cause the the car to lack that much in mph? I am running around 15-16 lbs of boost. I didnt have a scan tool with me, so I turned down the boost a couple pounds to make sure it wasnt getting kr and slowing it down up high, and my times got slower, and I lost a couple mph, so I turned it back up.

Mods are in sig. cant figure out what is causing the problem. I think that the exhaust leak might be contributing to it though.

Ben

 

[UNGN]

You can't expect much mph with a street chip and low boost. Street chips cut back timing in 3rd, killing mph. Your ET is pretty good for your mph indicating it's pulling OK in 2nd. Add octane and turn up the boost.

You need to fix any Crossover leaks as they will make the car run rich and screw up your launch. They will also screw with the boost.

Also, make sure you are not in OD.

 

[Red Regal T]

No Scanmaster? You need one.

 

[turbot2496]

Also comfirm the car is shifting between 4900 and 5100 rpms. If its shifting early it will kill the mph.

 

[Razor]

Ditto on the scanmasterII. Racing a Buick blind will end up really expensive.

Buy it now or after you build the motor. Hopefully before.

.02

 

[Momar]

Settle down guys, I have a scan tool. I have been using winaldl(cheap but seems to be effective at least for watching knock and such). My cable is broken right now. I was able to run up around 18 lbs w/ 0 kr when it was cooler. I turned the boost down to about 15-16 when it got warmer because I cant see whats going on until I get it fixed. I plan to get direct scan eventually.

Last time I posted, everyone said that my mph should be higher than it is. Also, this is a street car so I plan to run race gas for the most part, but do plan to get an alky kit soon but want to get my exhaust leak fixed, and make sure it is running right first.

Ben

 

[Hammer231]

With the boost that low and a stock turbo/intercooler combo I don't think that's too bad especially in the heat of summer. It's been a while since I've had that combo but I think I ran around mid 13s @101 mph with a similar street tune, street tires and cool weather.

 

[Momar]

I ran about the same mph in the cooler weather earlier this year, if not a little slower though. Does everyone agree that that is what I should be seeing, or should I be looking for a problem. That is on about 17 lbs boost. You said that you saw 101. That is still 3-4 mph higher than what I am seeing.

Also, do my quarter times seem to match what I am doing in the 1/8. I thought that they seem a little off.

I just want to make sure I shouldnt be looking for any other problems before I do other stuff. I am going to get my crossover exhaust leak fixed, and put the drag lites on before I go to the track next time. I am going to take the scan tool, and maybe play with the timing a little bit on the trans plus and see if If I can make any improvement.

Ben

 

[Razor]

If you need a cheap knock warning system, get the Caspers audible. Its less than 50 bucks.

Laptops cannot be used while racing. They are to be used after you race and see the events that transpired. Last thing you need is to record when the HG went.. cuase you were too busy being overwhelmed by events.

And personally I would hate to be racing someone that was busy looking at little numbers on a moving screen in the passenger area of the car instead of paying attention to the road ahead.

For low boost, and questionable tune, and issues too boot.. it did what it did. Be happy it drove home

Reason for the scanmaster is to offer on the fly numbers that can be used for tuning WOT which affects your MPH at the end of the track.

HTH

 

[Momar]

How reliable is the audible knock detector. Does it go off if there is any knock whatsoever, or at a certain point?

Also, I understand that the laptop is more for looking at afterward. Really want to know what was going on during the runs also though. The reason I didnt push the boost was because I cant tell whats going on though.

Ben

 

[turbot2496]

Razors dead on. The casper's audible is the best way to go. Goes of at a certain point, I think 4? degrees. Very reliable and fast because it gets the signal before it even goes to the computer. Sec and a half faster than scanmaster supposedly.

 

[Momar]

I still actually need one more sensor to fill up my pillar pod. I was looking at the caspers knock gauge. How do the led's on it corespond to kr?

Ben

 

[Razor]

Hey I said audible

Goes under the dash.. and makes noise when knock happens.. the more knock.. the more noise it makes. Even with a helmet I can hear it.

 

[Momar]

I know you said audible. I was just curious about the actual gauge too.

Ben

 

[turbot2496]

If you get the gauge you'll still want to get the audible too. Gauge don't beep. Check caspers site for info on the gauge.

 

[pacecarta]

DITTO on the audible , things happen to fast and your eyes cant be everywhere and usually are just looking forward ,
ill glance at the sm to be sure the o2s are there and sometimes get to glance at the boost gauge but theres no mistaking the audible as a signal to lift and its instantaneous .

ive found it take s about 4 degrees to trigger which means if your in third and you hear it, it time to lift off ! and save the car for another run , go back and reveiw the data you reorded and see if you can make some changes (drop boost or timing or raise FP or add fuel) to make sure the next run is knock free