Rb30/25 Conversion Tuning Dramas

[hipsiR33]

Hi all i am currently tuning my r33 skyline with a vipec ecu and dont know alot about it. currently the car sits at 392 hp but no mater how much we try it wont go past it. im running a garrett t38 and 20 psi is making this number and it should only be half of this the car makes 400ft/lbs of tourque and the car is on full song by 3000 rpm and just seems to fade off. it has all supporting parts for at least 500hp but the car just wont jump over the 392 mark. very frustrating and wondering if anyone has ideas as wot could be causing this????? the car did a water pump on the dyno but no overheating occoured as the problem was found before any damage took place. i would like to see my car hit the 480 mark so any help is appreciated cheers guys this is a fully forged engine

[Alf]

What size exhaust?

[r33_racer]

Might need to post more details in order for someone to come up with any decent help.

[hipsiR33]

ok sorry there. The car has a 3' turbo back exhaust, forged rods and pistons, steel head gasget, garett t38 turbo, 740cc injectors, saard fuel presure reg, walbro in tank fuel pump, plazmaman intercooler w 2 3/4 inch piping, greddy series 1 intake plenum, splitfire coil packs. its all ran by vipec ecu and on bp ultimate 98 octane. the thought im having is that the standard exhaust manifold is restricting flow but i have been told cars will make 500 with the standard

Edited November 17, 2010 by hipsiR33

[zebra]

What the heck is a T38 turbo?

and no the car wont make 500rwhp with a standard exhaust manifold in place

[STATUS]

if its full song by 3000rpm no way its gonna make much more than 260-280rwkw, the turbo technics (garret or copy) T38 has a 0.63 rear housing and was designed for small capacity engines around the 2-2.2litre range.... welll strangled on a 3litre

[hipsiR33]

I just found out that the turbo is actuall a garett gt40

[JonnoHR31]

gt40 on full song by 3000rpm? i want some of what your having

[hipsiR33]

Hey johno im looking for help not sarcasim so grow up im telling u thats wots going on the vipec computer has an anti lag program whch lets u bring the turbo on sooner

[Harey]

Dude relax, a GT40 is a very big turbo and no way is at full boost by 3,000rpm on a 3L engine. I am also confident that it would not bolt up to the standard exhaust manifolds, there just isnt enough room. You would need a high mount aftermarket manifold to run a GT40.

Find out what turbo you have (full details, exhaust housing and compressor size etc) and post it up here.

Do you have the dyno sheet thats only making 392rwhp? If so, post it up. To get the best help you need to provide as much info as possible. Oh yeah and change your font size back to normal its hard to read.

[hipsiR33]

The turbo is garett 35/40 and i dont have the dyno graph at hand. sorrry i cant be of anymore help for u 2 diagnose the problem. im not 100 percent sure but i think the cam timing has been advanced 36 degrees and this is thought to be the problem as it my be causing retarding of exaust cam

[KiwiRS4T]

At 12v your Walbro will deliver only 2/3 of the rated flow at 60psi (20psi boost). If you have not rewired it to full battery voltage it will most likely be getting even less than 12v and will deliver even less fuel. What does the afr graph look like approaching max power? I see Guilt Toy was at one point making 317rwkw and just changed from a Walbro to a Bosch 044 and managed to retune to 363rwkw. Some people have claimed 500hp with the stock exhaust manifold but you would definitely benefit from a 6boost or similar (as well as a new fuel supply).

[Adriano]

Mate to be honest there is 100 questions we can ask to help diagnose, but at the end of the day if the tuner cant diagnose it then you need a new tuner. However the stock manifold will definately be becoming a restriction much above what you are making.

[akaaa7]

is the tune mafless? if not ur afm could be out of resolution, z32's max out round 400hp i think?

Edited November 20, 2010 by akaaa7

[hipsiR33]

ok thanks for the advice guys we found the car had also jumped a tooth on timing so hoping to see some improvement. i would really like to see 480 hp from the car but would also settle for 450. air flow meter is not used on the car but still present. Yea the 6boost manifold is on my christmas list and i will hard wire the walbro and see wot happens i wanted the bosch 044 as i had 1 before and it died so i was advised about the walbro to be a better pump. but will bring this all up

[yogibear]

i want to see the dyno graph and pics of the motor of this gt40 on a stock manifold coming on at 3000rpm.

[Harey]

i want to see the dyno graph and pics of the motor of this gt40 on a stock manifold coming on at 3000rpm.

Post #11 says he got it wrong and its really a GT35/40. A GT35 starting to boost at 3000rpm on a 3L bottom end doesnt sound that hard to believe.

[TiTAN]

Post #11 says he got it wrong and its really a GT35/40. A GT35 starting to boost at 3000rpm on a 3L bottom end doesnt sound that hard to believe.

at 2500rpm my GT35 will give a few PSI at 3000 its giving 5-10 at 3500 its giving 18-20ish

[The Mafia]

I've done a fair bit of vipec tuning, puttings RB30s together, turbo matching, etc.

I Can see a lot of crap in your posts. If you want some help here, tell the story properly. Not just some shit thrown together in a post having us all guessing. I'll be nice and post some straight forward stuff. Like it or not. Its to the point.

1. First you mention your running antilag, to get the turbo to full boost at 3000rpm. Who sets that up permanently? You can't run that shit while the car is in any other gear other than neutral. So I'm calling bullshit right there.

2. Walboro Fuel pump, Sard fuel pressure regulator. Double whammy. I can say right now, you haven't stated the model of the fuel pump, and I'm somewhat thinking that you've probably gone out and randomly bought a "500hp walboro pump" which is most likely a GSS 342. These pumps are shit, and drop HEAPS of flow above 60 psi. Known fact. How to I know? My car made 295rwkw and the AFRs would not go below 12.8:1. Lucky for the water meth. And I personally think SARD regulators are shit, full stop. Had at least 4 of them just not work properly on cars, and give me the shits while trying to tune. I've told the owner of the car to bugger off and come back when the stock regulator is back on and at the factory base pressure. If you've got big enough injectors, and you do, then why the f**k do you need a regulator? Anything under 350rwkw and YOU DO NOT NEED A FUEL PRESSURE REGULATOR IF YOU HAVE THE RIGHT INJECTORS.

3. Standard Exhaust Manifold. Anything over 300rwkw (390rwhp) and you are wasting your time unless you have done something to it. I managed 314rwkw and most likely closer to 320rwkw, but I was running water meth and had bugger all boost control under 18psi.

4. Its clear that you have absolutely no idea what turbo you are running. So you do not have any idea what power you will make.

5. You are also aiming for that magic "Big number". Here are some questions you need to ask, or post here. What Torque are you making through the rev range? What power at 2000, 3000, 4000, 5000, 6000, 7000 RPM? Where is a dyno sheet? What gear are you even running? What are your inlet temps?

Its clear that you have just gone out and bought a stack of bullshit brand name parts without thinking, and are just aiming for that "Big magic number" and now you're having issues. Also, do you have a proper tuner tuning your car or are you just "having a go"?

I've seen way too many people "Having a go" and tuning so bloody wrong its not funny.

Anyone ever seen a PowerFC map all set to "1.0" and then the injectors f**ked around with to get the best "average power" ? I have... and in a R34 GTR.. Lucky I had a look and fixed it all up. The poor guy didn't know that how it was tuned for him.

Anyway, I've given you some pointers. If you want to ignore me - Then go right ahead. I've been there and done that, I'm not just guessing.

Edited January 3, 2011 by The Mafia

[Guilt-Toy]

good post Mafia...

I find its easier to cut apples with a steak knife then a butter knife.