Low buck combo, initial results

[Pablo]

Went to the track for some shakedown runs. I only got about four passes in.
My best slip was:
1.65 60'
7.17@96.5 mph

my highest mph was 97.4 on another run.

I was playing with the tune just trying to get the car to launch. I activated the nitrous for the launch on my best run. So that 1.65 was off the footbrake. The Nitrous shut off at about 15 psi. It was a pretty nice feeling. I want a 1.5 though.

I'm not sure what my boost was set at. In the heat of the runs I wasn't looking at the boost gauge. My datalog is inconclusive. According to the log I was only running about 20 psi. But as you can see from the image, something is going on with the signal from both the TPS and the MAP. I'm not sure what to make of it. At the elevation where I live it looks like 23 psi on my boost gauge. This track is at almost 1000 feet higher up. I'm not sure if that makes a difference. I'm also not sure if my gauge is a little off.

I have to figure out what goes wrong with the tps and map signal.

this datalog was not from my best run. I wasn't using n2o on this one. The launch was real soft. My computer did not want to datalog on my fast run for whatever reason
as you can see, my tps and map go crazy. I'm not sure why. The car is also rich at the beginning and leaning out at the end of the track. I'll have to figure that one out too.

So all in all I am pleased with the initial outing. Especially if it was only at 20 psi. I ran a nearly identical time with the stock longblock at up near 30 psi if not 30. When I turn the boost up this car should start to get crazy. If it was in fact at 23 psi then I think its still respectable. I'll have to sort this out.

 

[Pablo]

Here's a pic of the launch on the best run

 

[Pronto]

How about some details on your low buck combo. :wink:

 

[Rodney87GN]

Barona right? Did you run in that Mustangs vs the world event?

Anyway, those are very respectable runs...easily a high 6 second car once you get it all dialed in.

BTW what are you using to datalog?

 

[Pablo]

Yes, Barona. I just ran in the test and tune since it was my first outing with the car. The logger is an add on for my particular wide band set up (tech edge) It's old.

Here is my combo:

109 block
Girdled
Stock crank
Stock Rods
TRW forged .030 over pistons
Comp 212/212 flat tappet
stock rockers
Home ported heads (with homemade flowbench used to guide changes, approx. 190 cfm intake flow)
.060 Cometic gaskets
~8:1 compression
home ported intake manifold
Stock headers
TE-45a
3" THDP
Hooker 2.5" dual exhaust
Powerstroke I.C.
Twin M15 nozzle alcohol injection
72 lb/hr injectors
MAF genII translator with WB correction
Hofer Trans with CPT (the real art carr) 9/11 3600 stall converter
Sniper nitrous system on window switch only to spool the turbo
28x10.5 ET Drags

A couple of the things that make the combo cheap:
I didn't dynamic balance the rotating assembly. I only had the piston/rod combo weight balanced to eachother. And I used a very light piston pin combination. Yes, there is a method to this madness

I didn't have it torque plate honed.
Used a china girdle and studs

flat tappet cam
stock shaft rockers with adjustable pushrods
home ported heads.

originally used felpro hgs but that came back to haunt me.


Some other details about my run:
Converter was unlocked the whole pass
Timing was fixed at only 23 deg for the whole pass

upon further review I think boost may have been somewhere between 21-23. It's hard to tell since my logger data is so noisy. I think im getting RF interference on those particular sampling wires.

 

[Pablo]

upon even further review, I've found that I have roughly around 30% converter slippage as I'm going through the traps. Note my datalog has me finishing at about 5200 rpm and my trap speed was 96.5.

I will definitely be locking the converter once I get the launch tune where I want it. I really want a 1.5 60'. Until then I will leave it unlocked just to save some wear and tear on the car and the converter.

Any ideas on how much I will gain after I lock it? The only thing that concerns me is that it will pull my rpm down too much through the traps. I can run my 26" drag radials instead of my 28" slicks to compensate. I don't know how much that will help though.

 

[forcedfedv6]

upon even further review, I've found that I have roughly around 30% converter slippage as I'm going through the traps. Note my datalog has me finishing at about 5200 rpm and my trap speed was 96.5.

I will definitely be locking the converter once I get the launch tune where I want it. I really want a 1.5 60'. Until then I will leave it unlocked just to save some wear and tear on the car and the converter.

Any ideas on how much I will gain after I lock it? The only thing that concerns me is that it will pull my rpm down too much through the traps. I can run my 26" drag radials instead of my 28" slicks to compensate. I don't know how much that will help though.

1st congrats on your runs and the rust bucket staying together, 2nd i think you will gain at least 5mph once you lock the convertor so you will be around 101 to 102 as you pass the 1/8 mile marker, get a better launch and you will get a 6.90 or some timeslip. BTW you still running behind me with those times so keep chipping at it.

on another note your trannie maybe slipping or convertor maybe a little to lose on the top end, you should be going through the traps at around 5,800rpm no less..

 

[4timesT]

So locking the conerter is going to pick up 5 mph by the 1/8? Wow that's some inefficiency right there.

If the tranny was slipping or the converter was too loose, wouldn't the RPM be higher than it is right now?

One thing I think I see in the log is the AFR might be going a little lean upstairs.

 

[forcedfedv6]

So locking the conerter is going to pick up 5 mph by the 1/8? Wow that's some inefficiency right there.

If the tranny was slipping or the converter was too loose, wouldn't the RPM be higher than it is right now?

One thing I think I see in the log is the AFR might be going a little lean upstairs.

yes you are right, i made a mistake and if his trannie was slipping he would have a higher RPM through the traps and it would be the same if the convertor was too lose, I have seen car pic up as much as 3 t 5mph by locking up the Convertor..

 

[4timesT]

Ok cool, thought I was losing my mind lol

I figure 3 by the 1/8th and 5 by the 1/4 sounds about right.