PDA

View Full Version : GT2871R at the track



S14Redtop
06-01-2005, 03:48 PM
Went to a local booty raceway last night with some people. I haven't been to the track since last year when the car ran 12.8 at 118.6 on a Big 28 turbo running 21psi and stock cams with 18" volks and street tires.

This year the car has 264 step one cams and a gt2871R w/ 86AR turbo dynoing 412 hp and 341torque at 17.8psi
I was running (peak)18.8 psi at the track which is the max the car will do right now with boost falling off 1 psi to 17.8 on the top end (obviously something up with boost controller)

Made numerous passes in the 12.7 range, then suddenly bumped it to 12.3. Finally on the second the last run hit a....
http://memimage.cardomain.net/member_images/8/web/536000-536999/536500_55_full.jpg

This is on 18" volks, running 255 Kumho supra 712 tires.

Needless to say I about pissed myself i was so pumped!!

Just out of curiosity, does anybody know what the max boost a 2871R can handle. I've heard 400hp, which is where I'm at now boosting at 18psi, but I've also heard they can hold up to 25-26psi. I'm assuming at that boost should be WAY over 400.

By the way this is in an S14 with redtop SR20det


Anyway..11's...here I come!!
m

dryft_s15
06-01-2005, 03:53 PM
Get some slicks, drop the 60' time to at least a 1.8 and you'll be deep in the 11s.

And try not to fall asleep at the light. http://forums.freshalloy.com/images/graemlins/grin.gif

S14Redtop
06-01-2005, 03:58 PM
yea...reaction sux b/c I just wanted to run a good time and was not ready for the launch when the light went.

m

killjoy
06-01-2005, 04:23 PM
Get some drag radials. I hit 11.8 with 121 mph so you can hit mid 11's easy with a decent 60. Thats pretty good power for that turbo. What manifold are you using? Do you have a greddy or freddy manifold on the intake?

cwdmark
06-01-2005, 05:15 PM
he has a greddy intake and megan exhaust manifold..

yea very nice traps... damn s14mark beat me by 1/100 of a second!

cleveland 240's are representing. i think that megan manifold is actually doing something... thinking about getting one myself eventually.

TheRiotHero
06-01-2005, 05:22 PM
awesome, thats almost the exact setup im putting together for a customer right now, what headgasket are you using?

PhoenixTurboEric
06-01-2005, 05:27 PM
Nice times http://forums.freshalloy.com/images/graemlins/grin.gif

S14Redtop
06-01-2005, 07:59 PM
I got a question for another member and he points out what seems like an inconsitency since last time we hit this hp at 20-21psi.

Since the last time I ran I have changed my fuel filter (aeromotive) for one that flows up to 2000hp, and also the fuel sock on my fuel pump. The air/fuel was MUCH better on the dyno so we were able to pull some correction out of the SAFC. We had been adding about 32%, and now we are adding only about 20%. This probably allowed for less timing to be pulled out and thus the apparent higher horsepower on lower boost.
But after looking at my boost curves more..we've also noticed that I have retarded boost drop off to 17.8-18.8 no matter how high i set the boost. I didn't realize that the boost drop was that significant, and last time I quoted the HP figures I was looking at the peak on the SBC-id, not actually watching the whole run.
We did a run where the boost spiked to 20.5 and we hit the same HP 413 (since that is at redline and by then it's running 17-18psi), but the torque jumped up to 365.


hope this makes sense
Any input appreciated.
I'll scan the dyno charts to illustrate my point

mark

vitaminT
06-01-2005, 08:01 PM
Congrats on the times and on the power. Those are nice levels for that turbo.

S14Redtop
06-01-2005, 08:02 PM
forgot to answer the head gasket ?

Cometic 99$

m

cwdmark
06-01-2005, 08:37 PM
mark lets try the manual boost controller out to see if you can hold at least 20psi. i was watching the profec b on my run and it was holding 20psi to redline on the .64 trim, so i expect you can do at least that if not more, unless it comes down to the matching of the turbo to the compressor.

S14Redtop
06-01-2005, 08:51 PM
yea....manual boost controller is next and also I'll install that grounding kit that is on it's way. should hopefully make a difference. THEN consult!

m

gatecrasher
06-02-2005, 07:46 AM
nice times, especially for a car on plain jane radials.

cwdmark
06-02-2005, 10:42 AM
vids from the night

12.4 run
http://videos.streetfire.net/Player.aspx?fileid=47E9F8F1-FEBB-43C2-B77E-5A1DB557FBEB

12.0 run
http://videos.streetfire.net/Player.aspx?fileid=7A9CA512-EAB8-4A0D-9BC6-FFE7B492A3D4

killjoy
06-02-2005, 11:29 AM
Damn, thats just sad. All that spinning in 2nd gear. Please don't go back to the track until you have good tires:)

cwdmark
06-02-2005, 11:41 AM
i had the same thing when making a very hard 1>2 shift. street tires are o so very fun. not.

Vapor
06-02-2005, 12:20 PM
forget tire spin, what about that wheel hop http://forums.freshalloy.com/images/graemlins/shocked.gif your drivetrain is going to love you when you fix that. Good runs

JimStinksAtDorifto
06-02-2005, 04:04 PM
forget tire spin, what about that wheel hop http://forums.freshalloy.com/images/graemlins/shocked.gif your drivetrain is going to love you when you fix that. Good runs



agreed.
subframe spacers + taller sidewall + softer suspension if you can adjust it.

S14Redtop
06-02-2005, 06:37 PM
yea...it's pretty nutty how much wheel spin i had. If i could just cut that down about 10% i think it'd be 11's.

Actually the wheelhop is non existent. I had just got the aluminum subframe bushings in there and all that sound you hear is the undulation and bumpiness of the track in the first 60ft. LIke I said...S****Y track!


By the way...thanks for the vids mark. I hadn't seen those yet!
mark

90s13drifter
06-02-2005, 06:40 PM
What kind of diff are you running?

S14Redtop
06-02-2005, 07:16 PM
I'm running a 300zx ..i think the R200

PR_S14
06-02-2005, 08:14 PM
I'm running a 300zx ..i think the R200



Great run. The car sounds mean as hell.