AC CR43TS or AC CR42TS ?

[6SENSE]

Finally got ahold of some CR42TS's today. They had them at a Napa wharehouse store. I dont know why the person at the smaller Napa I went to yesterday said they couldnt get them!

I guess I will put them in and see how they work at the track tommorow. Not sure what Im going to gap them at though In the past I have ran boost as high as 26psi. However, since Im basically starting over with my tuning process now that I have Tlink, Ive turned the boost down a little lower to get started. Any suggestions?

Also, what type of differences should you see when going with this colder plug on our cars? (I know the 43's that I had been running are already colder than stock).

Thanks guys!

 

[TType84]

less knock? :-D

should help a bit if not.. well then my car was just weird then

 

[6SENSE]

CR42's are in. I went ahead and gapped them at about .032-.033. This is the tightest Ive ever gapped plugs for this car, always had 43's at .035.
Dont think its my imagination, but right off the bat the car seems to pull harder than before. When I just tap on the pedal it acts like it just wants to go, feels like my brothers '86 does. Most importantly it Feels to be pulling harder on topend .
I'll find out for sure tonight if I race, that will be the true test.

 

[turbo6x2]

Glad to hear it worked out for you. Sounds like the sales person at that Napa was just being lazy. You have to get to know a particular person at these places, the service usually improves 10 fold. I think you are finding out the benefits of running the colder plug...

 

[6SENSE]

Best run last night : 14.4@95, Best ever : 14.2@96

I guess it was my imagination!

I keep telling myself "tuning, tuning, tuning". Only one problem.... its not working! No matter what I adjust I run the same #s (i.e. fp high, fp low, boost high, boost low).
Maybe I just dont know what the heck Im doing. Or maybe something is just straigt up wrong with my motor. Its come to the point that I hope there is something wrong with it, I truly do. It would make me feel a whole lot better if I new that there was something holding me back, then I could just fix it. Maybe my cam has a wiped lobe? From the time a put the car together, a few years ago, I didnt like the way it idled at times (rough) or could I understand why the vac was so low (7-9 at idle). I posted a few times about the Poston GN107 cam and my idle/vac #s. Finally someone replied and basically said that was normal #s, they had the same cam and #s were similar. Or maybe both of our cams are wiped! I dont know.

 

[6SENSE]

I am trying so hard to not get too frustrated and just put the '87 engine in.
I have always felt that getting this hotair engine to perform would be so much more special. If I convert I will just be another one of the many. My car is like an endangered species out here. I like that....its different!
I have been extremely loyal to the hotair.....how many guys would still be messing with this '84 motor if he had a '87 sitting on the engine stand! Either loyal or plain stupid, right?

Justin


P.S. just to note, I havent been using the alky (mentioned in sig) at the track the last couple of times because I felt that I should be able to get times much lower without it. Then introduce it back in to go for extra.

 

[TType84]

how much boost can you run without knock:

1. off alky
2. on alky
3. off race gas
4. on race gas

if you are only running 14psi well then we know why you only went 14.2

13.6 took 17psi.

im sure the car wouldve run a 12 with the stock dp if i put in half a tank of 116 and turned the boost to 23psi

 

[WFO]

good point,are you running it at the track on pump gas and the thrasher 92?if so,get a race chip and some c16.

fwiw,i got 5 runs last time out.they were all with 24º of timing,same fuel on the me16,starting with low boost and working my way up.

~17 psi=13.45@99mph
~20 psi=13.07@102mph
~22 psi=12.84@105mph
~24 psi=12.67@106mph
~26 psi=12.58@107mph

the track is closed now,but if i was going to go out again i would make sure i had pure c16(had c16/c14/pump gas)and i would add a couple degrees of timing.if she liked it i'd add a couple more.

i honestly think i was starting to run into a wall with the flow of my stock intake/heads/cam.if you look at the #'s i added 6 mph with the first 5 psi,then 2 mph with the last 4 psi .that's getting into the sweet spot of my turbo too.like i said,i think there was some more in it with some more timing(give the fuel more time to burn)but i'm not sure how much more this thing's got in it without some real airflow improvements.

later,sean

 

[FJM568]

hmmm...I ran a 13.6 @ 105.5 with ~15# boost on 92 oct pump gas and an 18* street chip on street tires... and a 2.36 60' time Now, mine is now IC'd, so your results may vary...

 

[WFO]

stock heads/intake/cam?


also,in my experience if you spin on the line your mph will be higher than it would have been if you hooked up.

later,sean

 

[FJM568]

no/yes/no...

and yes...

No on the stock heads, I'm running the Stage Jr heads from David Chase...Basically a stock head, but with some cnc bowl word and the short side radius lowered...But the heads actually have no egr or heat crossover provisions cast into the head at all...

Yes on the stock intake...I'm running the lower intake from the 86/7 TR's but with a custom upper plenum that I made to allow me to run the turbo in the stock 85 location...

No on the stock cam...I'm running the CC 206/206...

And yes, lots of wheelspin off the line...

 

[6SENSE]

Thanks for the responses.

I like being singled out for my hotair car around here but sometimes it would really be nice to have a few more hotair guys around, that have made it further than me. There are alot of knowledgeable TR guys here, but as far as hotairs they dont really care too much. Kind of funny, Im the one people tend to ask when it comes to them. I guess, I have improved the car quite a bit over stock, about 1-1/2 seconds and 8 mph, but I built it expecting much more.
Anyway, no runs with race gas or slicks. All times have been 93 oct and street tires. Reason for this is that I wanted the car to be a true street car. I didnt think there should be any problem reaching mid to low 13’s in street trim, then enter the alky. Are you guys saying that I need to use race gas to go 13's and more importantly faster than 95-96 mph? That doesnt sound right. I dont want to just cover a problem by adding higher octane.
Didnt use race gas or alky this past Wednesday. Using JL street chip w/20 deg timing. Using Tlink (w/ boost sensing) for 2nd time. Objective starting out was to tune for no KR. RESULTS :

RUN#1 :
FP= 43, max boost= 20.3, low O2= 777@73mph, max KR= 9.9@33mph ; 60'= 2.3, 1/8= 9.46@75.41, 1/4= 14.7@92.45
(Had alot of wheel hop launching with 8psi~.)

RUN#2 : adjusted TPS slightly for higher WOT #(4.76 to 4.84). raised FP. changed nothing else.
FP= 45, max boost= 18.2, low O2= 773@76mph, max KR= 2.1@62mph ; 60'= 2.27, 1/8= 9.34@75.6, 1/4= 14.5@93.6
(launched with 3psi~. Was happy that KR went down. However, found out later that 4 frames after the 2.1 KR frame on Tlink were screwed up?! The readings were real weird : 0 vss, -40 cts, etc. and 0 ret of course). So I dont know if that was max KR or not).

RUN#3 : turned up boost 1 full turn (was thinking that 2.1 was max KR on last run). changed nothing else.
FP= 45, max boost= 23.3, low O2= 738@96mph, max KR= 16.6@96mph ; 60'= 2.43, 1/8= 9.65@72, 1/4= 15.02@92.5
(launched with 4psi~. Let off the pedal at I think the top of 2nd gear because audible KR sensor went off, then got back on it).

RUN#4 : turned FP up 3psi to match boost that went up 3psi (still thinking that only 2.1 KR on run#2 was correct).
FP= 48, max boost= 23.9, low O2= 758@89mph, max KR= 18.4@93mph ; 60'= 2.34, 1/8= 9.34@76.42, 1/4= 14.48@95.2
(launched with maybe 1psi. Tlink showed retard from 54mph to 93mph and I could definitely feel it on the top end during the run)

Any suggestions on where to go from here? Still just a tuning issue? Any other info that would be helpful for me to post ? (i.e. maf readings).

Thanks a lot for any suggestions! (hey, should I start a different post with this, or does it matter?)

 

[WFO]

Re: Thanks for the responses.

Originally posted by 6SENSE
All times have been 93 oct and street tires.
Using JL street chip w/20 deg timing.

RUN#1 :
max boost= 20.3, low O2= 777@73mph, max KR= 9.9@33mph

RUN#2 :
max boost= 18.2, low O2= 773@76mph, max KR= 2.1@62mph

RUN#3 :
max boost= 23.3, low O2= 738@96mph, max KR= 16.6@96mph

RUN#4 :
max boost= 23.9, low O2= 758@89mph, max KR= 18.4@93mph

Any suggestions on where to go from here? Still just a tuning issue?

holy sh!t,for the love of god TURN YOUR BOOST DOWN! i can't believe you didn't blow your headgaskets during those runs!

on pump gas with an intercooler and 18º chip i can run 18-19 psi with no knock.that's usually worth about 98-99 mph in the 1/4.

here's what you need to do:

1:turn your boost down to 16 psi
2:make passes in 3rd gear from ~50mph to~80/90 mph.
3:record the runs on t-link.
4:adjust your fuel pressure so you are getting decent o2 #'s(high 700's/low 800's)with less than 2 degrees of kr on the big end.

you may be able to turn the boost up a little bit once you start to get it dialed in.trust me,it'll be a whole lot faster with less boost and a proper tune than it is when it's knocking it's guts out .

later,sean

 

[WFO]

Originally posted by FJM568

Stage Jr heads from David Chase...Basically a stock head, but with some cnc bowl word and the short side radius lowered...

lower intake from the 86/7 TR's but with a custom upper plenum that I made

I'm running the CC 206/206...

well there ya go.you gots a lotta flow there that i'm definitely lacking.the only reason i'm getting any kind of mph is cuz i'm rammin some boost through there.

i'd like to see how far someone can take a stock longlblock without an intercooler.lots of timing,pure c16 and as much boost as it'll take.you'd think it'd go 12's with all the bolt ons...

 

[6SENSE]

Yes, I know, I know, the thought crossed my mind about the head gaskets in the past. I have had alot of KR on this car. I checked the compression a few weeks ago, seemed pretty good. All readings were between 115-130. Maybe its the 87 head gaskets, and .030 over forged?
#2 on your suggestions WFO, you are talking about rolling at 50 on the highway and hitting it up? And when you mention 3rd gear, are you saying have shifter in Drive, not Overdrive?

Thanks, anymore suggestions or comments from anyone would be much appreciated. Please be as critical as you want, I may have built it but I know I have been a dumb@#$* as far as tuning it!

 

[crazygn]

Drop the boost down like wfo said or up that fuel press a little, it looks like you are running to lean to me. What are your maf readings any way. Any thing under 20psi in my car is slow to me but with race gas and 20-25psi it can make a huge performance gain.

You can get more from tuning then bolting on parts and its free

 

[crazygn]

Yea wfo is talking about putting it in drive 3rd gear and floor it to see what your o2's are , because it will be at the end of the 1/4, at 3rd gear , best place to check it so you know you wont lean out on the top end.

i think you arerunning real lean on the top end.

 

[WFO]

yup,exactly.leave it in 3rd and wind it out.that's where the load is the highest so if you're gonna have kr that's where it should be.

as far as cyl pressure,it does seem a little low.87 headgaskets will lower your compression,but .030 overbore will raise it a little.

do you have a cam card for that poston's cam?from what you've been saying about it recently it sounds a little funky...did you degree it when you installed it?

later,sean

 

[WFO]

i see you're from st. louis,do you know dan smith or leo wagstaff?both cool cats from your area that could give you a hand if we can't get you figured out...

 

[6SENSE]

Here are my maximum MAF readings from those runs :

RUN#1 : 246 @ 33mph/5075rpms/832 O2s
RUN#2 : 244 @ 52mph/4425rpms/805 O2s
RUN#3 : 244 @ 19mph/3725rpms/816 O2s
RUN#4 : 242 @ 54mph/4550rpms/801 O2s

As far as the cam. No I did not degree it and yes I have the cam card in front of me. Above all this info it says data for degreeing cam at .050 tappet rise. Does this mean I should have degreed it? Ive installed plenty of cams in the past but never degreed any.

Lobe center : 111 exh, 103 int
Lift : 269, 269
Exhaust opens : 32 BBDC
Exhaust closes : 10 BTDC
Intake opens : 2 ATDC
Intake closes : 24 ABDC
Exhaust duration : 202
Intake duration : 202
Overlap : 0

(One note about the cam that always stayed on mind was that when I started the engine up for the first time I had trouble keeping it running. It was something with the CTS if I remember correctly. So it didnt get its ideal straight up to 2000+ rpm right away.)

And yes I know both Dan and Leo, and they are cool guys.

P.S. Not sure if that cam info above is the right stuff, or just for degreeing. Here is other info that I found that may be what you were asking for :
Lift : 430 int, 430 exh
Duration : 254 int, 254 exh
Valve Lash : - int, - exh
Open : 24 int, 58 exh
Close : 50 int, 16 exh