Completed Project My 98 super charged EX

[4pointslow]

Or

I could also try going with bigger exhaust and high flow cats? I would like quieter mufflers but won't sacrifice power.
One thing is that with 2 more lbs of boost there was not much of a power gain. Maybe I can test the back pressure at wot, but what would be good or bad?
On unmodified vehicles they say less than 3lbs. at Idle and no more than 7 or 8lbs. at WOT under load.

 

[ahodges]

13.4.......with the incorrect tune....dont ever want to see 14's again.....from a stock motor, and a v6 at that.....
you poor thing lol
it will go faster. i have no doubts about it the way it is now.
orrrrrrrrrrrr https://whipplesuperchargers.com/

Now we're talking!!

 

[Dono]

I forgot, stock exhaust.

On my 4.0 ohv, I kept popping the dpfe hose off until I opened up my exhaust.
That had to be robbing power, so I'd have to guess you have lots of back pressure also.

I'd think that even getting rid of that factory chambered muffler would make a huge difference.

 

[2000StreetRod]

+10 rwhp

I could also try going with bigger exhaust and high flow cats? I would like quieter mufflers but won't sacrifice power.
One thing is that with 2 more lbs of boost there was not much of a power gain. Maybe I can test the back pressure at wot, but what would be good or bad?
On unmodified vehicles they say less than 3lbs. at Idle and no more than 7 or 8lbs. at WOT under load.

I did a lot of research, ordered all of the parts myself and then paid a shop to put it all together. It ended up costing me $1,000 to gain 10 rwhp. I've never measured my back pressure but as I recall the Dynomax VT valve begins to open at about .5 psi. Judging from the sound of my exhaust I'd say the valve is full open at around 3,000 rpm.

 

[4pointslow]

Exhaust

I did change the muffler years ago.
Its a Flowmaster with 2 inlets and 1 outlet. The outlet is 3 inches.
I also have JBA headers (shorties).
The stock cat pipes just about fit on the end of the JBA's. Stock is 2 inch pipes on the cat pipes. I would like to go up to 2.25 or 2.5.
It looks like 2000streetrod proved that 2.5 would not fit on the drivers side so maybe 2.25 is the limit.
I don't know, I think the nitrous would be the best "bang" for the buck. Pun intended. I wonder with the smallest shot available, how many runs will the engine last?
I was looking into it a little and I know I will need to have a blow down tube since our trucks are like hatch backs. I will never purchase a used bottle. If the safety valve is tampered with and the pressure gets too high, the damage to vehicle or oneself would probably be fatal. I would only feel safe draining the bottle before parking it in the garage too. I am lucky enough to have a speed shop nearby, I will have to stop in there soon to start planning the system.

 

[Dono]

I agree, nitrous.
But, as you stated, there are huge obstacle's to overcome. it will be super interesting what you learn.

 

[4pointslow]

Atco Raceway

So this is supposed to be Atco Raceway's last weekend of the season in 2014.
I plan to be there tomorrow to try to beat a 13.34.
I have all my tunes with me, updated my Advantage3 software so I can make more if needed etc.
I guess I am getting up early tomorrow! Gates open at 9:00am, racing starts around 10:00am.

 

[2000StreetRod]

good luck!

I hope the weather is good and you beat your target time.

 

[vroomzoomboom]

dont forget washer fluid or what ever you use for the meth kit!
good luck, and try not to get kicked off the track for running too fast

 

[4pointslow]

12-13-14 New Time Slip

Today, 12-13-14, I ran a new best time.
My best runs were run 12 and 13. (I had 17 runs in before running low on gas)
Funny how it took me 13 days to install the head studs.
My best time before today was in the low 13's.
Check out the new times.
I should play the lottery.
(the MPH is messed up on the second one)

 

[vroomzoomboom]

like i just said on facebook, that picture just cost me a lot MORE money! lol
nice going john, i figured you would be in the 12's. now the real question is what do you think made the big difference in this e.t. vs the last time you shot down the track.

 

[4pointslow]

Difference

One, It was colder.
Two, I did a little weight reduction(spare tire,jack etc),
Three, I had the water meth tune where I added 10 degrees timing. The last time I could not access it so I was stuck with W/M and 4-6 degree's timing advance.
I was pulling low 13's all day but the tires were slipping off the line. The track was slippery, no sun for a while, starting line looks a bit tore up too. Since I was slipping off the line the transmission was shifting to soon from 1 to 2 and that made the engine hit rev limiter before going into 3.
I dropped the 2-3 shift mph from 52 to 50 and that fixed it and it ran the 2 12.93's. I want to try making my tune shift from rpm again instead of mph and see if it works better.

 

[2000StreetRod]

congratulations!

Those are impressive times. If you succeed with rpm shifting please post what you did. Mine shifts way early at WOT vs what's in the table.

 

[4pointslow]

Trans

First thing I did was change "Switch to use RPM anticipated shift" from 0 back to 1 which is the stock setting. See Pic 1
If I recall when set to 1 it uses rpm or mph, whatever comes first. When set to 0 it uses mph only. So I am setting it back to 1 and will raise mph to a higher number so it never hits the mph one first. That way if I have wheel spin I wont be bouncing off the rev limiter before the next shift.

Pic2
Then I checked the "Trans WOT shift RPM" settings for each shift. They are stock in this picture except for 4-5 is at 7000 to keep the transmission from shifting into 5th(O/D) at WOT which would damage the transmission quickly.
I have a test tune with the rpm's set to 5000. If it works I will raise it up from there to where I need it. I will experiment and see what rpm shifts give me better times.(5000-6000).

To change the mph shift points you go to "Trans shift schedule" and raise the mph for TP 500-600(wot) on up. You do it for each shift, 1-2, 2-3 etc. Make sure to read the notes and make sure shift points do not cross like the notes tell you.
See Pic 3

 

[2000StreetRod]

tried that

I think I calculated mph at rev limit 6250 and entered those values. Then I determined what I thought were my optimum shift points for engine speed and entered them. But as I recall the shifts happened at around 5800 rpm.
..... rpm mph
1>2 6150 56
2>3 6050 73
3>4 6350 96

 

[4pointslow]

early shifts

So if it shifts early from 1-2 you would try raising the rpm or mph or both to get the shift to happen later. You probably already know this, I am just putting here in words for future reference.

As we both found out there are many things in the tunes that don't match up exactly. lol.
My rpm's before and after the shift were so unbelievable in the tune I think they were purposely done like that to use rpm shifts only. I made some changes in my tune that made them more realistic, I think it was base N/V and gear ratio.

 

[2000StreetRod]

stock values

Below are the CDE4 stock values:

..... rpm mph
1>2 5500 66
2>3 5500 78
3>4 5800 91

The pro racer forum members seem to think that mph shifting is more accurate than rpm which is probably why you changed yours to begin with.

I did notice my axle ratio was 3.5 and the final drive ratio was 3.77 and the tire revs per mile was 800. Since the 4WABS module computes the vehicle speed I suspect only the tire revs per mile matter. I changed the gear ratios to 3.73 and the tire revs per mile to my actual 721 but that would only affect mph shifting assuming the rpms are set high enough. I'll be very interested in your testing.

 

[4pointslow]

trans shifts

Got to the track again today, got 9 runs in. Pulled three 12.9's.

Changing the RPM's to 5000 did not change a thing, tried 4000 as well and no effect. That was with the "Switch to use RPM anticipated shift" from 0 back to 1which is the stock setting. I hate it when things don't work like they should. lol.

My trans is shifting from 1 to 3 sometimes. The command and desired are both going from 1 to 3 it looks like. I believe it is something in the tune, it doesn't seem like a mechanical problem and there is no slipping. I think it is just accelerating to fast to go 1-2-3 sometimes. (the first to second and second to third shifts are close together and normally only drop the rpm from 6000 to 5000). Maybe some timer in the tune or some other setting I will need to adjust. I guess I have some more studying to do.
I will check the adjustment on the 2nd/OD band also.

I have to say it really ran great this weekend, sounded smooth felt smooth etc. Pulled hard. There were a lot of surprised people at the track too, including myself.

 

[vroomzoomboom]

i was going to say i bet you had a few people taking a double look at the time just to make sure they saw it correct lol

 

[4pointslow]

time slips

Yea,
like the guy handing out the time slips and even me! lol.