RB27 Tuning Update! Need Help.... Issues stilll...

[Shocker]

thanks guys, me and a crazy local DSM guy are going to try to dial in the exhaust cam shaft tonight back at ZERO degrees where it should be just tuning with fuel.

I made it to work today 30 miles away with no problems, got about 25ish mpg as well. I was surprised, it was cityish mileage, with a bit of country.

[kouki-gymkhana]

Where's the vids??!!?? Congrats on getting that beast back up! Do you have a build list? I'm curious to know what's going on with the bottom end of the motor, EMS, and ignition set up. Looks like 6 individual coils in the pic...

[Coolwhip]

Pull it back out and degree the beast.

[Shocker]

Pull it back out and degree the beast.

I took it over to his house last night, I checked out his car first. ****ing BEAST! heres a link to his dyno vid...

http://www.youtube.com/watch?v=mzW2xPqWjhE

Anyways we rotated the camshaft back to neutral where it should be. I locked it down with actual hex headed screws.

Car wouldn't even start now, lol, it took us about an hour of tweaking to get it to idle half decent. Its a bit high and rich but it works for the moment. We started tuning doing 500rpm increment 50% throttle pulls to around 6500, and stopped. A/F's under 50% TP are about 11.0's.

Ok HUGE difference now between retarded shaft and regular shaft. The car is an absolute ****ing monster.... 50mph roll 2nd gear 50% throttle and it breaks them free as if I was standing still....

I'm going down this Saturday to C-bus to hopefully finish the tune on the dyna-pac.. I pray to god it doesn't rain.... it would ruin my week.

EGT's are now way down and coolant temp is also staying stead at 180 even after pulls.. I most likely was heat soaking my bay with the shaft in that position.

Vid's will come once the car is finished being tuned.

Kouki is a Microtech lt12s unit, with 6 bosch coils, rb26 crank, eagle rods, JE pistons. ARP everything else. Equal length divided manifold, custom plenum. 740cc's.

[RB_Seth]

Thats awesome to hear you got your beast running good. I can't wait to see your car in person!

[gawdzilla]

your friend took his dsm all the way to ISP to get it dyno tuned? That shop is pretty close to me.

[mott6904]

Compressor surge sounds REDIC, it sounds so ****ing nasty..

Why is this? Is the Bov not working right, or is it just the turbo. I upgraded my turbo to a 60-1 and now it always sounds like it is surging. I was getting ready to buy a new bov, but if some turbos sound like then i wont.

[Shocker]

your friend took his dsm all the way to ISP to get it dyno tuned? That shop is pretty close to me.

Its where Brad Brooks was, his tuner, so its where he went. He did an amazing job tuning it, his numbers show that hah.

Seth sure thing man, you coming to Steel Valley Super Nats? Best bet on when to come! its at Quaker City Raceway.

Mott, surge only occurs at low boost when I let out, WOT pulls its all BOV. Its just how it is on small displacement motors with big singles. Not to mention I have a non anti-surge housing which makes it worse. No worries though!

I really hope the weekend turns out nice, I want to lay down some numbers and be done for a while.

[Shocker]

Well, not sure what to do now, I noticed my vent tubes on my valve covers were getting pushed up... signs of blow by. So I pulled the plugs all appear fine, but I noticed a thin coating of oil on the tops of my cylinders. Car smokes a bit when reved until warmed up then its hardly nothing. I did a compression test and we are between 130-145 psi not really where I'd want it, my compression ratio is now 8.5 so.. we got about 150psi when I first got her running on the dyno 6 weeks ago... It appears as if the rings are not seating properly...

Motor has about 700miles on it so far, I'm going to do a leak down test once the rain stops, its looking like the rings arnt sealing properly...

Not sure If I should follow through with the tune this weekend and see what happens or not. Maybe being so rich isn't helping these rings seat? Washing down the walls allowing for the blow by.

I just changed the oil, I might add some Lucas oil stabilizer before tuning if I decide to still do it.. not sure it would hurt now.

ehh.

[craz4240]

That totally sucks dude hopefully it's just a breakin thing,your afrs are quite rich.This will all work out I love this car...

[Shocker]

It seems as if the compression check isn't always the best gauge to use. I did a leak down test and all are in 2-4% except #5 which is at about 7% so it seems as if the rings are ok.

Its now appearing as if the valve stem seals are leaking, my oil is heavily sedated with fuel from running so rich during off idle normal driving. I'm seeing 10's to mid 12's a/f's under regular driving. Also the oil was slightly overfilled so I took some out as well.

I'm ordering new OEM o-rings for my injectors tomorrow since they are leaking. Also I'm done driving the car until Saturday when I make my 180 mile journey to get tuned. I'll change my oil before making pulls when I get down there to insure its straight and fine for punishment.

We will see what she does, hopefully all goes well I might just leave the pressure where its at currently on 1 BAR to keep it safe until I get everything dialed.

The car is already attracting a ton of attention. I was gang rushed by about 20 people in a parking lot last night going to pick up my cousin. Luckily a cop rolled in kicking everyone out only a few seconds later lol. (i'm not one to pop my hood I hate getting asked that question by random people...) :/

[rb25drag]

Did you replace the valve seals in your head? Im assuming so. Also did you happen to seet your valves properly in the head with rubbing compound before re-installing the valves?

I have seen this happen many times and cause I problem under load.

Hey what can we say, Our cars drags attention

Mine hardly makes it out of the garage so its hard for people to see unless they know me!!

[the converted]

Did you replace the valve seals in your head? Im assuming so. Also did you happen to seet your valves properly in the head with rubbing compound before re-installing the valves?

If you have your valves cut and the seats done you should NOT do that or you will ruin what you just paid to have done.

[rb25drag]

If you have your valves cut and the seats done you should NOT do that or you will ruin what you just paid to have done.

Yup exactly, But I don't think he had any head work done other than cams (Im assuming)

[Shocker]

Yup exactly, But I don't think he had any head work done other than cams (Im assuming)

Yeah cams only, valve seals were replaced.

I'll see what happens once tune is done and I get to change to regular oil.

[Coolwhip]

Get this damn thing running now!

(Just came across a 2.7L RB25 Build making 1000+whp)

:-D

[Darius]

I'm excited for you and I can't wait to see some more videos!

I just skimmed the rest of the thread, but did I read that you're running 10-12 AFRs during normal driving?? That is insanely rich! I don't run any lower than 13.5-14.5 in my normal driving/low-rpm cells and I'm thinking about leaning those out some more if I can keep the exhaust temps down and knock down as well.

[ItzGenX]

With my SR, I tuned the cruise AFR's to 16:1. Damn thing gets amazing gas mileage on a highway trip (33mpg). My light accel map (up to 18% throttle) is set to a target of 13.8-14.0 AFR. This helps the city driving with frequent stops to a decent 24mpg (21-22mpg with A/C city) as long as I don't get happy with the throttle. I never thought such aggressive cams could do so good on gas. 18%-25% throttle have a target AFR of 13.5-13.0. Any higher then that, it is 12.8-12.5. 80%-Full throttle run at 12.0 AFR across the board. These acceleration targets based on throttle % when you suddenly begin to step on the throttle (accelerator fuel enrichment). Almost all of this is ignored when it goes into a full accel mode and reads ONLY the boost/air temp vs rpm map. Full boost is still at a 11.8-12.0 AFR though .

[Shocker]

I might be ****ed at the moment for Saturday tuning.... I was supposed to get my new injector 0-rings today, but they didn't come. So I called Shay at Nismoparts he misunderstood what I wanted, overnighted me the parts...

So I figured I'd go outside and get the fuel rail off and so forth to get it ready, I dont have much time to work on my car tomorrow since I need to go and pick up my new DD after work

ANYWAYS! I found out why my ****ing fuel injectors are leaking! I never installed my ****ing o-ring bushings that stick in the plenum... I only can find 4 of the 6 I need.. Autozone cant get them till 3 pm Saturday, I tried making some, but the rubber when I tested it (not on the car) cant handle the heat and gas so it breaks down...

I'm praying I ordered the right o-rings from Shay... I don't think I did, I'm pretty sure I just got the ones for the body. I'm gonna call my local Nissan tomorrow to check if they have any in stock for the ka24de... also gonna call a local yard to see if they gotta DOHC 240 sitting down there that I can strip these rings off on Saturday morning... My buddy Peter down in c-bus is looking for 2 of them for me as well...

What a stupid but critical few dollar part....

[Coolwhip]

tisk

[240z4u]

Its always something dude!

Evan

[Shocker]

Yeah no kidding, not to mention I feel like an idiot for never installing them...

Hopefully myself of my buddy can track down 2 today. I found a guy about 50 miles from me whose selling two ka24de's hopefully he can help me out...

[Darius]

Are you describing the lower injector bushing things? If so, I hear ya. I was going to replace mine with new ones but didn't know what they were called and didn't want to wait to get parts so I installed my existing ones. Does anyone have a part number for those things and/or a cross-reference on a USDM vehicle?

[Shocker]

Are you describing the lower injector bushing things? If so, I hear ya. I was going to replace mine with new ones but didn't know what they were called and didn't want to wait to get parts so I installed my existing ones. Does anyone have a part number for those things and/or a cross-reference on a USDM vehicle?

ka24de should work, I just ordered some from my buddy it will be here later today. From the picture I saw at A-zone they appear to be the same. I sure as **** hope they are.

yeah thats what I'm talking about as well.

[Shocker]

They don't appear to be the same from the pic's my buddies dad who ordered them just sent me.... This might be a custom part here... Unless anyone can think of or knowns of a USDM replacement vehicle...

[craz4240]

I am using Supra Lower isolators with my RX-7 injectors,their a little thicker but should work.

[Shocker]

Ok just did some phone calling, 300zx 94+ lower insulators are CLOSE but not quite.

I called RC Engineering the lovely lady on the phone informed me an 89 240sx insulator bushing is the same....... so I'm gonna try to order one and pray that it is.

[Shocker]

Nope 89 240sx insulators are NOT the same.. not even close. I might be semi ****ed, tomorrows a negative now, I've gotta figure out something here... I'm gonna see If I can find some hose line big enough for it.

[craz4240]

Use toyota supra lower isolators lol

[Shocker]

Use toyota supra lower isolators lol

called and tried, the guy gave me dimensions for them and they weren't very close....

I made my own out of 5/8" inch ID heater hose. Seem to be holding just fine.

I fixed my catch can issue as well today. No final tuning though.... I'm not sure when I'm going to be able to head down.