Less than impressed at the track.

[jdmser]

A couple weeks ago I went to the track for the first time this year. It's the first time since the car has been running well with the new mods. The current setup is this: stock rb20 bottom end, ported and polished head, tomei 260* 8.8 lift cams, tomei springs, sard 720(flowed at 735cc), 29x8x3.5 fmic and custom 2.5 piping, Garrett t3/to4e 50 trim .70 compressor and .63 turbine, custom 3" downpipe, 80mm 5zigen catback, Zex spool shot jetted for 55hp, q45 maf w/ Stillen popcharger, emanage, and a chip by Carl. I have a manuel boost control set at 19psi and the wastegate is a z31 style internal gate that I ported. It holds rock solid, no spikes. I was launch at 3500rpm and didn't feel like I was coming off the line hard enough. The bottle kept it from bogging down though. What do you guys think? I personally thought it was slow for what's done.

My best slip:R/T 1.232 60' 2.238 330' 6.035 1/8 9.071 MPH 82.92 1000 11.601 1/4 13.761 MPH 104.81

[slo_coupe]

i would think you should be running faster times than that with your mods. Were you having traction issues or something?

[jdmser]

No traction issue really. It would spin a little while shifting but, not a ton. It was mainly coming off the line. I'm going to try launching at a higher rpm next time. The nitrous was keeping it from bogging down but, the lag in 1st was still pretty bad.

[Darius]

Those are like stock RB25 times and traps. You should be running faster. Might need some more tuning on your chip. Do you have a wideband to see what your AFRs are?

I have found that trying to launch a turbo car without a two-step tends to bog it down unless you launch from something like 5000 rpm. The engine is not building boost without load, so the car doesn't leave the line with much power.

[jdmser]

I saw the af's dropping down into the low 10s when I'd hit full boost but, didn't log anything.

[HxC_Nismo]

i launch my car at 5500 rpm and i cut 1.7-1.8 60ft and run mid to low 12's and i run mickey thompson drag radials on mine.

[rb25drag]

Your 60' is hurting you alot. Doesn't look like your coming out of the hole all to well. Last night On my Rb25 with the Gizzmo launch control @ 3600RPM I cut a 2.5 60' with a broke driveshaft LOL

But if you have good sticky tires I would think a 1.6-1.8 60' at the Least.

What Rear end are you running?

What Springs/Shock setup do you have?

All of these things will Play a huge roll in getting the car out of the hole.

I would think you could leave at 4500 without hurting anything.

[db_s13]

yea i have a completely stock rb20 and i ran a 14.6 with terrible traction and major wheeel hop gettin off throttle in second to stop bouncing around and a 2.6 60 foot, if i get my 60' down id be right there

[Yellow4g63]

A couple weeks ago I went to the track for the first time this year. It's the first time since the car has been running well with the new mods. The current setup is this: stock rb20 bottom end, ported and polished head, tomei 260* 8.8 lift cams, tomei springs, sard 720(flowed at 735cc), 29x8x3.5 fmic and custom 2.5 piping, Garrett t3/to4e 50 trim .70 compressor and .63 turbine, custom 3" downpipe, 80mm 5zigen catback, Zex spool shot jetted for 55hp, q45 maf w/ Stillen popcharger, emanage, and a chip by Carl. I have a manuel boost control set at 19psi and the wastegate is a z31 style internal gate that I ported. It holds rock solid, no spikes. I was launch at 3500rpm and didn't feel like I was coming off the line hard enough. The bottle kept it from bogging down though. What do you guys think? I personally thought it was slow for what's done.

My best slip:R/T 1.232 60' 2.238 330' 6.035 1/8 9.071 MPH 82.92 1000 11.601 1/4 13.761 MPH 104.81

Did you dyno tune it? I ran a 13.7@99 with a 2.2 60' with just Downpipe, exhuast, untuned PFC and boost going from 14 to 10psi. I had BFG's on for that run. Might just need to throw it on a dyno and get it tuned.

[240z4u]

I saw the af's dropping down into the low 10s when I'd hit full boost but, didn't log anything.

Richer then bill gates!

Thats what happened to your power.

Evan

[jdmser]

I'm running a R33 4.36 rear end with kyb agx and eibach sportlines. For right now I have a Nitto 555 245/45/17 but, I'd like to find some draglites with a set of et streets. If I can't I'll problely go with the 555R drag radials. I've also been thinking about finding a set of stock spring for the rear.

[lilskyline240]

ur 60' is whats killin ya man. If you cut that down to 1.8's you'll take a full second or more off your 1/4

[Shocker]

Yeah but the MPH is just not there... I'd expect 112-116 ish....

[Yellow4g63]

DYNO TUNE!!!!! lol maybe more timing is needed.

[Kansei240sx]

get rid of those AGX's and Sportlines, thats what is hurting you.

Put in the factory struts and springs, and if needed some new subframe bushings to keep it from shifting under a launch like that. Sticky tires also help.

Modified and lowered suspension will **** you up out there.

Either that or you need to learn the sweet spot on your car.

My friend sean has a bone stock blacktop SR and was running a 13 flat, with a similar suspension setup and he hasnt had much drag experience either.

[wawazat8402]

I didnt see adjustable cam gears on your list of mods. Do you have a way to dial the cams in? That will make a big difference. Also, need to get it tuned on a dyno. Im not discounting Carl H's ability at all, he gets tons of good feedback but every car in each location is a little different. You will need to fine tune for your setup if you want to get the most out of your car.

[lilskyline240]

i dont realy think its his setup thats the main problem. You just need more seat time at the track and youll see times going into the 12's. But definitely get it to a dyno to get it fine tuned

[SuicidnS13]

Yea a 104mph trap is a very low trap speed for your setup. Especially at that high of boost. Definately get a baseline dyno just to see where you are at currently. I suspect you have a very conservative tune or something else is not right with in your setup? 10.0afr is very rich IMO.

[jdmser]

I know a dyno tune would help out a lot but, with the RB24 short block going in this winter I really want to save the dyno tune for it.

[Yellow4g63]

I know a dyno tune would help out a lot but, with the RB24 short block going in this winter I really want to save the dyno tune for it.

Could be vacuum leaks or exhaust leaks. Everyone is right tho you should be trapping why higher than that. Are you running a draw through setup or blow?

[jdmser]

It's draw through just like factory except I replaced the soft inlet tube with a 3" mandrel 90. I've fixed all the vacuum leaks I could find and it has good vacuum at idle most of the time. Usually has about 15hg of vacuum but, sometimes it will lean out at idle. The afr goes to 18 and the vacuum drops to 10hg but, it doesn't die. It then goes back to normal after a minute or so.

[Jo240sx]

i would say get some slicks throw that 60' down to a 1.8 and you'll probly see a 13 flat. with all those mods you need something to lay it down with.....

[S14-NEO]

I saw the af's dropping down into the low 10s when I'd hit full boost but, didn't log anything.

WOW!!!....that car wont make any kind of power with that kind of AFR's..you need to be in the mid to high 11's to wake that engine up...your dumping soo much fuel that i would be willing to bet your thinning out your oil running that rich and washing down your cylinders with that kind of fuel getting in there...LEAN IT OUT FOR CHRISTS SAKE!!!!!

[lilskyline240]

prolly has a huge boost leak makin it that rich

[jdmser]

I've check a couple times for boost leaks and that's not it. What if the stock recirc valve was leaking too much? It doesn't sound the same as when I first finished the swap but, I'm running it through a soft hose now in stead of the stock pipe.

[lilskyline240]

if u still have it recirculated it wouldnt make u run rich because the leaking air is going bcak to the intake

[WhatsADSM]

Something is grossly out of whack. My last S14 with an RB20, GT32, 550s and a mild tune ran low 13s at like 109 on something like 16psi.

You really want to take that thing to someone reputable and get it tuned. You can have all the hardware in the world but if the car isn't tuned right it is useless.

Also as others have stated, boost leak check, and also run a compression check just to make sure things look okay.

[jdmser]

I think I have it figured out. I didn't have my laptop with we so I couldn't look at the emanage. A while back I started to lean out up top so I add 15% fuel from 5k up just to be safe. Then after that I found that the nut to the fpr had come loose and fuel pressure had worked it's way down to 36psi. Well, I brought it back up to 40psi but, I never took the extra fuel out. A resent log shows afr at boost are in between 11.3 and 11.8.

[nissandrftr88]

It still shouldn't be that slow,my stock rb20 runs 12.6xx's consistantly and also got a 12.4xx out of it.Maybe you should get it tuned better then Get some slicks and get your 60' way down.they need to be around 1.85 or better.your suspension should be fine.I run JIC coilover's and there 6's in the back and 8's in the front while still cutting 1.78 60'.
Modified by nissandrftr88 at 9:38 AM 5/7/2008

[HxC_Nismo]

hey jdmser are you going to midnight madness this friday night at gateway? if so ill be there cause im going to try and hit the 11's with my new tune and diff/axle setup. if you see me there come on over and say hi.