Low mph need some ideals

[turbot2496]

My car doesn't seem to be running enough mph in the 1/4 and I could use some input why, throw some ideals out there and maybe it'll get my gears turning I'll try to give you as much data as possible

Track Slips 4 best from fri night

.................... Run 1... Run 2... Run 3... Run 4
60'................ 1.751__ 1.739__ 1.793__ 1.816
330............... 5.361__ 5.315__ 5.335__ 5.371
1/8............... 8.366__ 8.403__ 8.424__ 8.388
mph/1/8......... 81.05__ 80.36__ 80.09__ 81.95
1000............. 11.035_ 11.075_ 11.106_ 11.034
1/4............... 13.313_ 13.339_ 13.376_ 13.290
mph.............. 98.66__ 99.23__ 98.95__ 99.64

The car.. 87 GN 140000 mi Stock turbo, untouched cleaned intercooler, K&N Filter(clean), hotwired 307 fuel pump, 50# injectors, hooker dual exhaust no cat, slicks @12 psi, adj timing chip for alky, old smc alky kit. Running 93 oct and 100% denatured. Tuning with scanmaster. New valve springs. Fresh rebuilt trans w/ new 2800rpm stall convertor. Compression tested 138 on all cylinders. New autolite 23's. TPS adjusted correctly. No floor mat and confirmed full throttle. TV cable adjusted properly and trans shifting good. 210/205 cam that was put in when stocker went flat. Fuel pressure 43psi line off.

Some more info .... I was launching the car pretty hard at about 10 psi of boost to get these times. I was progressively adding boost and showing very minor improvement. When I started out the night I was running 21psi through the traps and steadily increased it to 24 psi. That was about the ceiling before the car would register some retard. I played with the timing also steadily turning it up run to run until retard showed. First run indicated above timing was 21/23 at about 22 psi. Last run timing was 22/27 and 24psi of boost. Adding the 1 degree in first and sec gear seemed to make a signifigant difference but the track closed before I could try anymore. Never added or subtracted any fuel. Car was not popping or acting up in any way, just doesn't seem to be pulling like it should. 02's through the traps were between 7.60-7.90 all night. Any runs where my audible knock sensor went off I got out of and either added more alky or turned it down for the next run. Alky was coming in at about 14-15 pounds with the minimum spray to quench detonation. Eventually at 24 psi I was running almost top setting on smc to keep down retard.

The fastest the car has ever run was a 13.01 at 99mph with the TC locked and running Race Gas and with a hurt transmission. I didn't ever lock the TC on these runs but if I would have I could have probably matched my best time on 114oct. Car has never broke 100 mph in the quarter. This week I'm gonna leave the slicks at home and soft launch the car and just tune to get the mph up. I gonna use race gas and a 29 degree race chip and see if I get some improvement in the mph.

By looking at the timeslips the car seems to be launching ok but it just doesn't seem to be pulling like it should through the final 1/8th. I would like to see at least 104mph.

When I go back I'm going to lower the boost back to about 20psi and tune from there with a ceiling of 22psi. I'm thinking of just leaning it out until its running as fast as possible at 20-22 psi and going no higher in boost.

I know I need to get direct scan one of these days but other than that if you have any ideals for me let me know. My goals with the car are to run as fast as I can with the stock stuff and this just may be as fast as the poor old car can go . I do need to do some porting work on the intercooler and turbo some day.

 

[pacecarta]

you list timing as 22/27 do you mean 27/22?

i ran very similar to your setup but stock cam , and with stock turbo ran

1.689 4.918 7.727 87.02 10.185 12.291 106.6

that was with locked converter 5150rpm at the traps and 1527egt 27/22 timing, 26" tires (actually 25 3/4 ) boost was about 25 in 1st , 26 in second but dropped a couple pounds during the run . and i was running a powerplate

you should try running 27* for the 1-2 timing to get the car out of the hole , you shouldnt need to launch with so much boost since spoolup shouldnt be an issue , my biggest problem became getting the tires to stick once it left .


what size slicks? , if 28" you may want to try a 26" tire

 

[turbot2496]

Oops.... You are correct. The chip is a 23/21 my bad. Which would have made my timing for the final run 24/25 Hmmmm..... I was raising the timing in 3 and 4 because thats where I thought I needed to gain power. Slicks are 26' and I am running a powerplate, I forgot to add that.

Thanks for sharing your timeslip. It looks like I should be running quite a bit more mph in the first 1/8th. In the first 1/8th I'm about 7mph off your times. In the last 1/8th I'm picking up between 18 and 19 mph which I thought was low but your car picked up 19 mph also in the final 1/8th which tells me I need to find that speed in the first 1/8th and that low timing is probably the problem.

I will take your advice and try to run alot more timing in first and second and probably back the timing off a little in 3 and 4. Also sounds like I should just leave that boost cranked up if I have no KR.

 

[steve davis]

Dont Put The Car In Over Drive While Running The 1/4

 

[turbot2496]

Never do. Thanx

 

[turbot2496]

Ok went back to the track last friday and ran 112 oct ,instead of alcohol, and street tires soft launching just trying to get the mph up. With timing set at 27/23 running about 25# of boost I was able to run a best mph of 100.4. Too much boost I know but the car wasn't knocking so I turned it up. In hindsight I should have removed fuel instead of turning up the boost like I said I would originally. Very slight improvement.

Went to the track the next day and ran a best of 12.98 at 102.4 with the convertor locked. It was very hot(about 100deg) so I'm sure that didn't help anything. Weird thing is when I locked my convertor on the first run I had to get out of it as I was getting some knock and my o2's were low.. in the 660 range. This seemed weird because the only thing I changed from the night before was adding slicks and locking the convertor but maybe its normal I dunno. o2's were 770-780 the night before with the convertor unlocked. I added some fuel in the chip and it got the o2's back up. I would have liked to played around some more but only got 4 runs. On the bright side the car is getting slightly faster but I still have a ways to go. According to most sources I should be able to run 109mph eventually with the convertor locked but probably not on a 100d day.

I sent my chip off for a base timing increase and will see if that gets me anywhere. Also installing direct scan this week so maybe I can figure out my tune. Next trip I guess I'll lower the boost to 21# again and see how much timing I can run and see if I get any improvement. Its fun playing around with the old car, nice to finally have some time.

Best pass was

60'___ 1.783
330___5.282
1\8___8.229
mph___83.3
1000__10.796
1/4___12.988
mph___102.4

25#'s boost timing @27/23 112oct.

 

[ll3lue]

Dont Put The Car In Over Drive While Running The 1/4

why not? (sorry newbie chiming in lol)

 

[justabuickv6]

Disregard the below. Just re-read your sig and noticed you already have..

*******
Have you replaced the valve springs? I noticed you have 140k miles.

If not, it's a cheap replacement and it gave me 2 mph in the 1/4.

I have 100k on mine. It rev'd faster, better throttle response and the entire RPM range felt so much stronger.

It took me about 4 hrs to do both sides. $68.00 w/ tool.

 

[turbot2496]

Hmmm... Friend found a small crack on my drivers side header I never caught.... Got header off and I have a small crack forming from a previous repair that is running a 1/4 of the way around the #5 tube. I'll get this repaired and get back at it but its possible my cars probably been pig rich this whole time with the o2 sensor reading wrong. I can't believe how easy the DS header came off... It was a breeze with no problems... ole car usually gives me a little fight. Maybe its just resting up for the install.


Also ll3lue I believe you don't want to run in overdrive because you don't want the car shifting at the end.... it kills the mph on most cars. You do better winding out 3rd gear.

 

[Quick6'n'-K.C.]

I see you are having some over rich issues. Stock turbo, 50s AND meth

During this post, i dont see your sig listed once.

I read this "adj timing chip for alky" is this a TT chip?

First you definitely need to fix the header leak, but that is another issue.

My advise would be for you to change your spark plugs and 02 sensor just because you have been running race gas.

I always find it if my car just starts running slow, new plugs and 02 sensor seems to wake it up, mine isnt just the only one. Do them at the same time.

I went to BG and raced a few years ago, my first pass was a 13.0 at 99 I was running 110 octane.
The ONLY things i did was change the 02 sensor, changed all 6 spark plugs and reset the ECU becuase of how crappy it was running. Started the car 3 times and went to the pits.
FIRST PASS: The car picked right back to where it should be, 12.21 at 110mph - 112 all week long, stock turbo, IC ect, ported lower intake, power plate ect.

Yes, that is all i did to the car, 02 and plugs, reset the chip.




Once you get the header fixed, do the 02 and plugs and see where your 02s are at.
Do you have a EGT meter? If not buy one. Dial the car in at 1650 right thru the traps.

Honestly i think you have too big of injectors on your car, find out how much the injectors are trimmed back to.
From talking with my buddies with 50s and 009s running meth, their injectors are basically trimmed back to close to the stock 28# injectors Or a little more depending on mods.

Another little bity story here.
Buddies car was running TTA with TE44 and stock injectors with meth
Car always ran 11.8 119.8 on radials with full exhaust and 2.5 downpipe
Bolted on 50s, never got above 116 for along time.
3 years later and extensively tuning his car, its up to 123.9 with a te45a on meth.

Well ive rambled too much.
Where am i going with this.... OH YEAH...

You only gained 1 mph going from alky to racegas.
Look at your 1/8th to 1/4 mile MPH GAIN.

Looks consistant on alky
Run 1 17.61 MPH
RUN 2 18.87
RUN 3 18.86
RUN 4 17.69


Race gas pass
Best pass 19.1

What im saying is to truely see how well the car is responding is look at the 1/8th to 1/4 mph GAIN.

Although you went 102 with racegas, you also locked the convertor too, thats where you got the 2mph above 100.

Sorry to bore you so much, here is a slip of my car on 110 at BG, maybe this can help you see that your car is working great, i think its bogging off the line even with those good 60's or second gear is shot.

Here you go
60' 1.76
330 4.99
660 7.71 AT 90.40
1000FT 10.08
12.09 AT 111.54

This is a Eric Marshall race chip, it only gains 21.14, you arent that far behind.
Port the intakes,power plate,hardpipe for maf, remove one screen.

If this pic works, you can see i was running 21psi of boost, and the bottom far right numbers are each pass GAIN from 1/8th to 1/4.

Does the car seem to fall down once the alky hits?

 

[Quick6'n'-K.C.]

Ooops first pass was worse than i remember.

 

[QUIP'6']

I see you are having some over rich issues. Stock turbo, 50s AND meth

During this post, i dont see your sig listed once.

I read this "adj timing chip for alky" is this a TT chip?

First you definitely need to fix the header leak, but that is another issue.

My advise would be for you to change your spark plugs and 02 sensor just because you have been running race gas.

I always find it if my car just starts running slow, new plugs and 02 sensor seems to wake it up, mine isnt just the only one. Do them at the same time.

I went to BG and raced a few years ago, my first pass was a 13.0 at 99 I was running 110 octane.
The ONLY things i did was change the 02 sensor, changed all 6 spark plugs and reset the ECU becuase of how crappy it was running. Started the car 3 times and went to the pits.
FIRST PASS: The car picked right back to where it should be, 12.21 at 110mph - 112 all week long, stock turbo, IC ect, ported lower intake, power plate ect.

Yes, that is all i did to the car, 02 and plugs, reset the chip.




Once you get the header fixed, do the 02 and plugs and see where your 02s are at.
Do you have a EGT meter? If not buy one. Dial the car in at 1650 right thru the traps.

Honestly i think you have too big of injectors on your car, find out how much the injectors are trimmed back to.
From talking with my buddies with 50s and 009s running meth, their injectors are basically trimmed back to close to the stock 28# injectors Or a little more depending on mods.

Another little bity story here.
Buddies car was running TTA with TE44 and stock injectors with meth
Car always ran 11.8 119.8 on radials with full exhaust and 2.5 downpipe
Bolted on 50s, never got above 116 for along time.
3 years later and extensively tuning his car, its up to 123.9 with a te45a on meth.

Well ive rambled too much.
Where am i going with this.... OH YEAH...

You only gained 1 mph going from alky to racegas.
Look at your 1/8th to 1/4 mile MPH GAIN.

Looks consistant on alky
Run 1 17.61 MPH
RUN 2 18.87
RUN 3 18.86
RUN 4 17.69


Race gas pass
Best pass 19.1

What im saying is to truely see how well the car is responding is look at the 1/8th to 1/4 mph GAIN.

Although you went 102 with racegas, you also locked the convertor too, thats where you got the 2mph above 100.

Sorry to bore you so much, here is a slip of my car on 110 at BG, maybe this can help you see that your car is working great, i think its bogging off the line even with those good 60's or second gear is shot.

Here you go
60' 1.76
330 4.99
660 7.71 AT 90.40
1000FT 10.08
12.09 AT 111.54

This is a Eric Marshall race chip, it only gains 21.14, you arent that far behind.
Port the intakes,power plate,hardpipe for maf, remove one screen.

If this pic works, you can see i was running 21psi of boost, and the bottom far right numbers are each pass GAIN from 1/8th to 1/4.

Does the car seem to fall down once the alky hits?

hey bw did you get my message. sorry to hijack

 

[Quick6'n'-K.C.]

hey bw did you get my message. sorry to hijack

Just got it after those 2 posts.I will pm you about your convertor.
BW

 

[QUIP'6']

Just got it after those 2 posts.I will pm you about your convertor.
BW

thanks

 

[turbot2496]

Thanks for the input Bryan. The plugs are brand new. They were installed right before I went to the track to run the numbers in the first post. Wouldn't hurt to swap them out though.

The o2 is a realitively new denso. It hasn't had much leaded fuel run through it but its cheap to swap it out with a new one and see if it makes a difference.

Chip is a TT from Eric.

I do have egt gauge in the car.

Injectors were bought to replace worn out stockers. I went a little big so I wouldn't have to replace them for awhile down the road. Everybody says you can turn them down to run like stockers so we'll see.

2nd gear shouldn't be shot... Trans is fresh with an alto wide band and it doesn't feel like its slipping.

Yeah, I agree locking the convertor was probably solely responsible for the mph gain.

After I get the header welded I will head back and hopefully do a little better. I've installed DS in the car so I will have a clearer picture of whats going on. Hopefully I can turn down the boost and up the timing and get somewhat better numbers.

Thanks for sharing your data. Lots of great info and ideals.

I set the turn on point pretty high on the alky and don't really notice when it kicks on.

This is the first summer in a very long time where the job isn't so hectic and I've had a chance to play with the car at the track. Car is not where it should be but I'm having fun getting it there.

 

[UNGN]

why not? (sorry newbie chiming in lol)

The car will shift into OD in the 1/4 around 100 mph, killing mph.

A 26" tire car with a locked up converter should top out at about 113 mph in drive, so there is no need to use OD if your car is slower than this. If your car is faster than 105-110 mph, switch to 28" tires.

 

[don86T]

What are your EGT's through the traps?

 

[turbot2496]

1550-1600 degrees

 

[don86T]

I would drop the timing to 26/24 (with race gas) or even 24/24. Make sure you aren't getting any knock. Then trim the fuel to get the EGTs to around 1650. Again 0 knock. Also run your slicks and launch at the same boost level every run for consistency.

Also have you checked to make sure all your brakes are free?

You may want to uncap the exhaust to see if that helps.

Don

 

[turbot2496]

Installed new pads and turned drums on back last month. I'll jack it up and double check to make sure everythings spinning free.

By uncorking the exhaust are you meaning getting rid of the cat convertor or running a dump pipe? The car has no cat on it right now and I don't really want to mess with installing a dump pipe at this time.

Thanks for the advice Don, I'll work on it when I get the header back on.