I am running a 94 SER with all the bolt ons with the JWT S3's and all I run is a 15.8-16.3 Utah is a very high altitude track and they say take off 1 sec due to the altitude here, but can I tune anything or adjust my AGX's anyway to help? I lower the tire pressure to about 30 PSI and launch about 4000 RPM and still get slow 60' times. (2.6) Any advice would be appreciated.

30 psi? Thats kinda high. Arnt the tires supposed to be at about 32 normally? Try lowering the pressure a little more. Also you if you havnt done the regular tune up items id do those.

2.6 :eek: Lower tire pressures to low 20's and try again! for drag racing, try to make your rear struts stiffer to minimize weight transfer off of your drive wheels.

Are you using street tires? How much wheelspin are you getting? If you are using street tires, that sounds like an awful high launch rpm. I can't launch at any higher than 3,000 without getting wheelspin all through first gear.

I run the Pirelli P700's at 30 PSI and the max is like 40 something and I have also tried to run with the Yokohama Advan032r's and actually ran slower on those than my street tires. (I know the Advans are road race tires and not drag radials) I get a little wheel spin but not much but I am trying to launch so my car gets in that torque range to pick up some time. So If I run a 16.1 here which would actually be 15.1 in most states does that sound about right?

Like everyone else said, lower your tire pressure to the 20's, the low 20's even. Dont pay attention to the max pressure the tire holds, if you have been running your tires at 40 + psi, then i would suggest you stop that immediately. Your tires must be hard as rocks. Normal driving in my nx2k calls for 33 psi in front and 29 psi in the back. Thats on the stock tire size.....now i run around 33 psi in the front and around 31 psi in the rears. Check in the inside of your door for your tire info. Also, like Chris said, make the rear struts stiffer, and also raise ur back tire pressure to the high 30's or even touch 40 when drag racing, this provides less rolling resistance for the hole shot (not to quote jesse from fast and the furious but i couldnt help it). And lastly, if u are going to launch that high, dont drop the clutch. Either ride the clutch a bit or regulate the gas off the line without flooring it to get better 60 foot times. If you can improve those, then your quarter mile will drop a few tenths to a half a second.

All the tire/launch advice these guys gave is spot on.

You didn't give a trap speed though, so there's no way to tell if your car is actually making the power it should. With all your mods, you should see traps in the 93-95mph range in good conditions. Since you're so high up, I would probably say getting a 91-92mph trap speed should indicate that your car is in a good state of tune. If not, then check timing, plugs, do a MAF reground, check your TPS and bump it up a little if you need to. Little things like that can add up and make your car get back lost hp.

Good luck!

Oh yeah I forgot what about shifting, my car seems to stop picking up major gains after 7000rpm and I was wondering when some of you guys shift. I figure if I shifted a little sooner then I could be in 4th gear for a little more than just at the finish line, and what about power shifting/speed shifting (not letting off the gas while you shift) is this any help or does it hurt your times?

Well, I see that you don't have the JWT ECU, so that means your power might drop off a little bit after 6800 to 7000 rpms. It also depends a lot on gearing. I have seen that most people run first all the way to 7000 and then shift at 6800rpm's thereafter. But...everyone's car is different depending on their mods, so you'll have to just experiment (getting consistent launches) and see what improves your times.

Antonio: these are two of my recent times. My timing is set at 13-14 degrees due to the S3's and I have new Denso Iridium plugs. I have never heard of doing a MAF reground or adjusting the TPS. I'd imagine I could do a search and out how. Let me know what you think of these slips:

RT------------.938------------1.109
60------------2.584----------2.586
330----------7.057-----------7.006
1/8-----------10.704---------10.622
MPH----------67.01-----------68.31
1000---------13.844---------13.748
1/4-----------16.489---------16.382
MPH----------84.38-----------85.17

85mph sounds kind of low to me, especially with all your mods. Your shift points most likely has something to do with that though. I would shift at redline from 1-2 and 2-3, especially with cams. Leave it in third if you can as you cross the traps (you should be able to if you have a classic).

Do the maintenance items like TPS adjustment and MAF reground. Also, SR20s are real finicky about what types of plugs they like. I would stick with NGK copper or platinum plugs. You can get a set of BKR6Es for $10 or less. Run the biggest gap you can get away with. I would just keep your timing at 15* to keep throttle response nice and snappy. You might have to change/check other things like distributor, cap, rotor, plug wires, fuel filter, etc.

One thing I just thought of is did you make sure you installed the cams correctly? You might want to double check you didn't skip a tooth. Doing so will cost you about 20hp. If you think that might be the case, set the engine to TDC, pull the VC, and count to see if there are 20 pins between the timing marks. You might want to check the archives on this procedure since I'm fuzzy on some of the details. I would do all the "easy" stuff first though.

Good luck!

who installed the cams? Are you sure it was installed correctly? Im 90% sure that the cam timing is off by a notch on the cam sprocket. Thats why you car feels slugish below 7000RPM and suddenl pulls hard after. CHECK YOUR CAM TIMING!

My cams were installed by a local Nissan Master Technician with 20 years of exp. I think that they are installed correctly. My car sucks ass from idle to about 3000rpm or so and at 4400/4500rpm the cams kick in and pull hard until 7000 rpm then if kinda drops off. I am going to change my plugs to the NGK's and I am going to change the fuel filter and do the MAF reground and see how it runs then.

just because a master tech installed it doesnt mean hes perfect. My friends car had the exact same problem after installing cams. S3's should not lag on the bottom end. The reason why it feels like it pulls so hard after 4K RPM's is because the low end is really shitty with the cam misadjusted.

Thanks for the advice Shoe but I just dont think that the cams are the problem. When I say my car lags under I mean that is seems kinda slow but still picks up speed. If I pull the valve cover off can I tell by a visual check if they are installed correctly? (i'm not a mechanic by trade and that's why I paid this guy to install them for me) My car started to overheat today so I think I might need to figure that out before I worry about this power loss. THX

why would you need to check the timing? Does the timing become off over time. Are there like mileage intervals where you need to check the timing to make sure it's not off? Why would you need to do a maf reground? What does that do? And what's the point of bumping up the TPS?

guys..those are the 60' and 1/8 mile timeslips i am getting in my ga16 powered car with only wai, exhaust, and advanced timing. something is surely off.

Originally posted by SR20RACER
Antonio: these are two of my recent times. My timing is set at 13-14 degrees due to the S3's and I have new Denso Iridium plugs. I have never heard of doing a MAF reground or adjusting the TPS. I'd imagine I could do a search and out how. Let me know what you think of these slips:

RT------------.938------------1.109
60------------2.584----------2.586
330----------7.057-----------7.006
1/8-----------10.704---------10.622
MPH----------67.01-----------68.31
1000---------13.844---------13.748
1/4-----------16.489---------16.382
MPH----------84.38-----------85.17

I was getting close to those kind of 60 ft. times with my GA16DE with an automatic! I had a *Pacesetter* Header that was horribly made (modified to fit but then had a 1/2" dent on the primary pipe), intake, NGK wires, NGK plugs, slightly advanced timing, and exhaust. Also, my stall converter was at 2,500rpm! (I can't wait till I chew out the local shop for messing with my Level10 3,200rpm stall that worked!) My car (B13) was also gutted but it still had power everything including air conditioner.

Reaction ----- .493
60 ft --------- 2.661
330ft -------- 7.361
ET @ 594ft -10.568
1/8 ET ------ 11.283
1/8 MPH --- 62.93

Those 1/8 mile times were faster than mine, mine were both 11.2 :( My RT's were .493 and .529. What would it mean if my trap speeds were 62.93 mph? Higher the better or what? Katana200sx, what were your timeslips like?

Since then I returned the Pacesetter header and I made a custom CAI: http://1minute.com/dan/images/cai4.jpg

Exactly what altitude are you at?

Since you have a 94, do you have the lowport or high port engine?

Play with the timing, at high altitude you should be able to run more w less chance of detonation.

But also check all the tuneup items. (MAF ground, TPS, plugs etc.)

Overheating symptoms indicate you may have problems with your headgasket, which leads to loss of compression.

I would bet if you run a leakdown test, bubbles would appear in your radiator (open the radiator cap). If two adjacent cylinders are low..bingo.

I could also mean that you are leaning out. You may also want to check your fuel supply....check fuel pump pressure at idle as well as wot.