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Discussion Starter · #1 · (Edited)
Hello all,

I recently fitted new 2860-5 turbos to my 33gtr. Replace cambelt and water pump also in addition to a new CAS sensor as the old one broke.

I have taken the car for a few long drives so far and has driven nicely, but I don't feel it pulling until I reach to about 5500rpm. From what I have read this is certainly not normal!??

I put on HPI elbows as well as HKS downpipe with a 3inch decat and Invidia RS-R exhaust. It's running Splitfire coilpacks and NGK BCPR7ES plugs. Fuel pressure is between 2 to 2.5 bar and it has 700cc injectors. It also has tomei poncams type B and tomei adjustable cam gears.

I have a Profec II boost controller and using the stock actuators that came with the turbo as I have read these are good for up to 1.5bar. I don't plan to run any more boost.

On my apexi pfc the hand controller reads 20deg ignition timing at roughly 900rpm idle.

I have read these hit full boost much earlier? The GT-SS I had before were very punchy down low and I didn't think -5's were too much different from them...

The car is booked in with the mapper next week...hasn't been mapped since I did the work on it.

I know I should wait to see what the tuner says...but I am wondering if anyone has any ideas as to what it might be as I am a bit impatient and want to check over things if I can before I take it to the tuner. :)

please advice.

thanks :wavey:
 

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You have exact same spec as me and mine is not laggy :/ actually mine is pretty responsive. Maybe your boostcontrol isnt setup right? as i know the profec and AVCR can control spool to. Could be the map to though.
 

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Discussion Starter · #5 ·
haven't checked for boost leak, but there is no drop in boost pressure and rises steadily and holds.

map hasn't been tweaked at all ....yet to take to tuner...but as far as I am aware, these tubbies aren't that different to the gt-ss (-9s) and thus shouldn't be a huge difference...

just wanted to see what people thought and if anyone has had this before.
 

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Maybe change fuel filter and re-check fuel pressure with vac. line removed.
Are you positive your cam timing is correct, it's easy to be a tooth out.
Did you check IGN timing with timing light after that cam belt service?
PFC doesn't know what your base timing is, it presumes you set the CAS correctly and displays 20 degrees (or whatever) from that assumption.
 

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Discussion Starter · #8 ·
According to the manual I remember reading that it's supposed to be around 2.5 bar idle vac removed. So i thought that was fine.
Also I didn't know about that base timing thing regarding the pfc. I followed the guide how to do Cam belt service and made all the marks and put everything back based on the markings including timing belt and cas sensor. I have adjustable Cam pulleys and they are on stock setting..0 deg. So I need to check the ign timing with the light then....something for me to tell the tuner :)
 

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According to the manual I remember reading that it's supposed to be around 2.5 bar idle vac removed. So i thought that was fine.
Also I didn't know about that base timing thing regarding the pfc. I followed the guide how to do Cam belt service and made all the marks and put everything back based on the markings including timing belt and cas sensor. I have adjustable Cam pulleys and they are on stock setting..0 deg. So I need to check the ign timing with the light then....something for me to tell the tuner :)
if your cas isn't minty mint, I know from experience even by marking it it can be out when you put it back, make sure you have no leaks by pressure testing the whole system from the turbo inlet (this is a must) and that both actuators are set equal and get it set up properly if you want the best from the car.
 

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Discussion Starter · #10 ·
It's a used Mitsubishi cas I got from a friend. Haven't done a leak test yet but the tuner will do it. I didn't touch the actuators as they are garret ones that were with the turbo when I bought it so I didn't think there was any way to tweak the setting. Thanks for the info....did you always do your base timing with a gun after you did a Cam belt change?
 

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It's a used Mitsubishi cas I got from a friend. Haven't done a leak test yet but the tuner will do it. I didn't touch the actuators as they are garret ones that were with the turbo when I bought it so I didn't think there was any way to tweak the setting. Thanks for the info....did you always do your base timing with a gun after you did a Cam belt change?
I got my r33 within 1 degree but the cas was marked and mint, on my old r32 I marked the cas but it was iirc 7 degrees out :eek:

-5s are laggy but you should be into full boost before 5000 rpm
heres my old dyno plot at rising sun 1.2 bar on -5s



as you can see 400 lbft by about 4500 rpm
 

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Discussion Starter · #12 ·
Wow 7 degrees out...definitely need a timing gun then to verify. I thought the pfc hand could controller did the job of the gun in showing the timing......curiously how much peak power did you make at 1.5bar (if you went that high)...ta
I made 497 with my gt-ss previously and decided to go with these...and hoping to get upwards of 550 at least... Fingers crossed...
 

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Wow 7 degrees out...definitely need a timing gun then to verify. I thought the pfc hand could controller did the job of the gun in showing the timing......curiously how much peak power did you make at 1.5bar (if you went that high)...ta
I made 497 with my gt-ss previously and decided to go with these...and hoping to get upwards of 550 at least... Fingers crossed...

1 bar made 522 hp, 1.2 bar 544hp, so roughly 1.4 bar 566 hp and 1.6 bar 588 hp, my opinion of -5s is 1.7 bar 600 hp is about the limit realistically on pump fuel, or a silly dyno correction will show 700 crank hp for them ;) lol

I did run 1.65 bar spike with 1.35 bar held and it felt noticeably quicker but that was just the spike making it feel faster than it actually was, 1.65 bar held would make good power, would need big injectors also. I stopped at 1.35 bar held as my 660cc injectors were running 96% duty with a base pressure of 3.5 bar :eek: lol

also a single fuel pump is getting near its limits so I ran a new tomei hardwired for constant 14v and didn't suffer pressure drop at about 565 hp, I had z32 afms aswell the twin rb25s I had ran out of flow

if you run 1.5 bar you should hit 550 hp, I hade a slightly worked head and stage 1 cams aswell to make 544 hp at 1.2 bar.
 

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also for reference ive had -7s on a stock rb26 and it made 450 hp at 1.2 bar
 

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Discussion Starter · #15 ·
Interesting regarding the hard wiring the fuel pump. According to the specs I have a nismo pump...but haven't seen it myself lol. I suppose I should see what power it makes and if the tuner suggests fuel pump is maxed out then it's time to change it. I would be a very happy chap if I made 560-580 :) still a dream at the moment....
 

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If the timing is retarded, the car will run like a dog.
If your cambelt tension isnt "just right" and/or you have not set the timing with a light, its almost 100% chance that the timing is wrong.
 

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Couple of this, I think cam timing here is the important bit, I do not believe it was ever set right even though with the GTSS they came on boost earlier, the acceleration was not savage for what was 1.5 bar IIRC. I also think something is not right with the boost controller, my AVCR feels much different and holds the boost pretty well. Poss leak or something.

The car was said to have been running way too rich at WOT, not sure of how good the map was but I suspect that they turned down the fuel pressure on the 700cc injectors at 2.5 bar or 37psi will give you 645cc. Rest would have been done through the map.
 

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Discussion Starter · #19 ·
When i fitted back my original cas sensor without the cambelt cover, I think it must have been full retarded (lol) and then it was adjusted slowly to get it right.

Then the damn thing broke.
The new cas is fitted with the cambelt cover back on where i marked it initially and I thought timing wouldnt be affected.

Anyway, just spoke to the tuner where my car is booked in for next week and he said they will check the timing and also look for boost leaks. I am hoping it is nothing to do with the cam gears or the belt being a tooth out or something like that.

I told him the fuel pressure with the vac line removed was 2.5bar and he said it was too low and would have expected around 3bar, same as people have suggested here.

He also mentioned that maybe the wastegate actuators don't have the correct spring preload on them? I have no idea as these are brand new garrett turbos with garrett actuators and I didn't touch the preload on these as I assumed they are fine from factory.

I do agree that the timing and fuel pressure is off...but curiously has anyone altered the stock actuators preload that they get with the turbo before fitting the turbo on the car?

Ta
 
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