17 second RB20DET?

[boosted240sxXxX]

ok guys, i took my 1990 240sx Hatch with a stock RB20DET (except for the 300ZX fuel pump and front mount intercooler) to the drag strip yesterday and it ran nothing but 17.3-17.9. im guessing this is unusual for a RB20DET. it feels sluggish after 1st gear and sumtimes it backfires. idk what is wrong. any help would be appreciated. thanx.

-Rick
Modified by boosted240sxXxX at 1:44 PM 7/18/2009

[Vkoslak]

sounds like its running rich or timing is off. Or both. Did you upgrade the fuel pressure regulator? The 300ZX twin turbo fuel pump will overpower the stock fpr.

[Shocker]

Have any boost leaks? Could it rev to redline? How does it idle? You should be in the 14's @ mid 90's-100mph

[240sx2jz]

rb20det dont run mid 14s he should be running high 15s low 16s stock

[Cjmartz2k]

Not in an S chassis they don't. 14's is about right.

[RustspecS13]

He was shifting at the stock redline. On an uncalibrated dohc tach.

That is his main problem. He also said that he doesn't build more then 7PSI in 1st gear, I think he might also have an exhaust leak.

~Alex

[DriftingisLame]

I ran a 14.1 @ 98 with my rb20 when it was stock + front mount in my s13.

Then got a good exhaust, a diff, and an safc tune and hit a 13.6 @ 103.

You really need to give us more details about your runs. 60 foot times, trap speeds, et's, all give us a lot more info.

If you're not in the 14's something will probably be incredibly wrong feeling about the powerband, you should work this out before you go to the track again.

Is it misfiring a lot?

Let us know so we can get this worked out.

[cdorhout]

sounds like its running rich or timing is off. Or both. Did you upgrade the fuel pressure regulator? The 300ZX twin turbo fuel pump will overpower the stock fpr.

+1Start with the basics. Make sure your mechanical timing is correct. Then make sure you have no boost leaks.

[240sx2jz]

i have seen a stock rb20det run an he could run better then 15.3

also not saying that yall dont run 14s just making a statement... also just wondering what do S13 with RB25DET run stock then?

[RustspecS13]

I guess you gues missed it in my last post.

Hes shifting at around 4K, since he has an uncalibrated dohc tach and is shifting at stock redline.

Then besides that hes not building full boost in 1st gear so hes probably loosing some HP.

But I'll go check it out in person some time soon here and see whats going on. Us rb20 locals gotta stick together.

~Alex

[boosted240sxXxX]

I ran a 14.1 @ 98 with my rb20 when it was stock + front mount in my s13.

Then got a good exhaust, a diff, and an safc tune and hit a 13.6 @ 103.

You really need to give us more details about your runs. 60 foot times, trap speeds, et's, all give us a lot more info.

If you're not in the 14's something will probably be incredibly wrong feeling about the powerband, you should work this out before you go to the track again.

Is it misfiring a lot?

Let us know so we can get this worked out.

ok here is the 60 foot, and trap, and my 1/8 from my best run=

60'=2.8

Trap=83 MPH

1/8=11.3

1/4=17.3

[DriftingisLame]

Okay thats the worst 60' ever. I dont know where to start, it sounds like you really do have bad power issues, I trust that its impossible for you to be that bad of a driver.

Do you have noticable misfires?

That is the only thing I see that can be extreme enough to take away that much power. 83 mph trap is probably worse than a stock ka24de would run.

My stock ka24de automatic ran a 2.5 60' and a 16.7. My buddy's SOHC manual ran a 2.4 60' and a 16.7.

Surely you have driveability issues, and can feel an extreme lack of power on the street, right?

[black240jl]

yeah should def be around 14and 11 in the 1/8 whoa mine ran a 8.8 in the 1/8 isnt completly stock but thats spinning 1st-3rd can hook up worth a poo and its mostly stock with 13.5 psi im upgrading now tho havnt had my rb for about a year

[Carl H]

shoot your base timing and get a calibrated tach, shifting at redline on the stock tach = worthless.stock tach reads 1.5x high with the rb signal

[rb25det250sx]

my rb25 stock ran a 12.7 1/4,8.4 1/8,trap 104mph60ft. 2.1

this is all stock sus. street tires.

do you have your boost cylanoid(sorry bout spelling)hooked up? 7psi is stock. mine ran 5 without the cylanoid. and still ran 9.9 in the 1/8 with my timing belt skipped a tooth and my timing set at 20* which was way off BTW. and i was shooting fireballs when i shifted!

[93slicktoptt]

yea it should def run low 14's .my stock ka24de ran 15.5's all day long

[nissandrftr88]

i ran 12.4 in my stock rb20 on 14psi....you def need to ckeck something out.I would recomend doing a leak down test.I got a bad motor one time and it ran 14.5 on 18psi and 80 shot.