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ok, now I know it's not just me, because I've heard one other report. The power comes on differently, and I have had to adjust the boost gain. In one respect, I can use lower gain because the pipe allows the turbos to hit harder without pushing the boost gain too high. But on the other hand, it's clear - my car builds boost more slowly from around 0.3~1.0 bar. Back to back testing was easy, it takes 10 minutes to swap pipes.

However, the car itself feels smoother and seems to pull more smartly, even though the boost gauge is reading lower. So I'm really at a loss to explain what is happening. I know plenty of people have just slapped on the pipe and made no other adjustments and enjoyed improvements, and my car's top end power is a bit higher, almost unstreetable (in Seoul I mean, not some highway in Montana). In other words, there were times in traffic when I could wind up the car WOT. I need an empty road now to go full boost. Well, it's not like night and day, but enough to notice "whoa, that's a bit more kick than it had before".

I also found a boost setting that made the turbos shuffle again. In general, the pipe seems to ask for the boost gain to be raised. The only problem is that with the gain set that high, the boost controller can't hit target boost and overshoots. I'm probably doing something wrong, but if I set the gain low enough (around 64 on the Power FC) so that the boost controller hits 1.75bar (what I've got it set at), lag is unbearable. With the gain at 73~74, I hit 1.87~1.90 bars, regardless of the actual boost setting.

Maybe I ought to install my ball-valve manual boost controller...
 

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^^^
Have you thought about getting rid of the PFC boost controller and going to a duel solenoid unit? I did and my boost needle appreciates the Blitz SBC ID Spec R. Comes on boost earlier and doesnt spike as much. You have alot more control then the gastric PFC one. A mate of mine noticed the same sorta thing when he installed the PFC unit into his R33 GTR.
Food for thought?
 

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Toby's boost "issues" have arose since fitting the modded TT pipe, nothing to do with his Pfc..........
I'm having the same complaint, on the road,(pensioner stylee), super smooth, shuffle free !.......on the track Sunday.....my normally responsive stock turbo's have turned into "lag monsters"......could'nt turn the gain up enough to get it how it was before the pipe mod !!??

Anyone want to swap a stock pipe for my modded 1 ?
 

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Toby's boost "issues" have arose since fitting the modded TT pipe, nothing to do with his Pfc..........
I'm having the same complaint, on the road,(pensioner stylee), super smooth, shuffle free !.......on the track Sunday.....my normally responsive stock turbo's have turned into "lag monsters"......could'nt turn the gain up enough to get it how it was before the pipe mod !!??

Anyone want to swap a stock pipe for my modded 1 ?
i will mate 1 dibs please
 

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The first thing i thought of after the initial test run with the modded pipe on was a boost leak somewhere, i have checked and double checked, cannot find any leak. I will strip all the boost pipe's this week, (and pressure test the i/cooler), if i find a leak, i will post an apology for posting misleading information:nervous:

Lee.
 

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Tyndago,
Have you read the PM i sent you ?

I was at the track on Sunday, the lag between shifts was embarassing..
i'm well confused...........

Lee.
 

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Discussion Starter #109
One theory. Rear intake pipe collapsing under load. Maybe.

Doesn't make a lot of sense. As I said I have tested this mod on the dyno, and driven the R32 on the drag strip and track a bit. No "lag" with GT-RS turbos. You can watch my videos of me at Buttonwillow or Streets of Willow. Also in car from drag racing - [email protected] mph.

I saw the PM, but I would rather air it here.
 

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Having read through this thread...where exactly is the evidence that suggests this mod is a good idea? All of it seems speculation to me, no hard facts. Reports that "the car feels smoother.." hardly makes it a good idea. Those "smokey" videos dont seem very convincing either. Sure some of the theory is plausible, but where are the dynographs or logs that show a significant improvement. Sorry if I missed it, but I dont see it...anywhere.
 

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No dyno's or figures but this modified pipe has taken away about 90% of the shuffle I was experiencing hovering around + and - vac that is fact.

Charlie.
 

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Discussion Starter #113
No dyno's or figures but this modified pipe has taken away about 90% of the shuffle I was experiencing hovering around + and - vac that is fact.

Charlie.
Back to back dyno charts are in the beginning of this thread. I personally tested it on a car on our dyno at RB here in the US.

I am not trying to sell anything to anyone. Just stating what I saw on the cars I have tested this on.

Its pretty simple. A divider in a tube. It does help with shuffle.

Not sure why you are so skeptical.
 

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The first thing i thought of after the initial test run with the modded pipe on was a boost leak somewhere, i have checked and double checked, cannot find any leak. I will strip all the boost pipe's this week, (and pressure test the i/cooler), if i find a leak, i will post an apology for posting misleading information:nervous:

Lee.
Hi Lee,
sorry to hear you are having difficulty.
PM me your number and i'll call you. Providing I made it and you aren't happy, i'll give full refund and replacement pipe in the post next day. We've received nothing but praise for this so far, as a result I'm pretty confident it's an installation issue.

Stupid question, but check that the gasket between front turbo and the modified pipe is properly in place, i've seen them hanging out before now!
Ian
 

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for me, I'm not particularly skeptical, hell, I paid over $200 for the thing. I'm just finding that on my car, adjustments were required. Or it could be that I was used to the way the turbos reacted so much that maybe I'm tweaking to try to get a peakier hit - 600bhp with lots of lag hits hard when it comes in and the surge in acceleration is scary/exciting. 600bhp in a Carrera GT is so smooth it's nearly boring.

Earlier boost makes for smoother power delivery = faster = less G force hitting = feels "slower" because the acceleration is more progressive rather than all at once. Never said my car was actually slower.

One thing I don't get however is why my boost seems to come in slower below 1 bar - past 1 bar all hell breaks loose. The car actually seems to pull a LOT better at part throttle at low RPM, even though boost seems to be down 0.2~0.3 bars at lower speeds. Could be that I'm using less throttle because the engine is flowing air more efficiently. In other words, my imagination.
 

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or maybe I didn't torque the pipe down to the front turbo tight enough - I used a small ratchet box wrench and gave it my all....what's the torque setting for those two nuts holding the pipe to the turbo?

I discount the boost leak theory. I have a wideband running full time in my car and if anything, I'm running a touch leaner - any leaks and the wideband swings rich in a big hurry.
 

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FFS this is going round in circles....
There is no guesswork from my end and I'm not skeptical at all.

1. My car "DOES" feel smoother
2. It HAS helped the shuffle I was getting.
3. "I" do not have back to back dyno figures for this mod.
4. IMO this is a GOOD mod.

OUT!
 

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you can do the following, datalogg AFR with the stock unmodified pipe. then without modifying anything, in the same day as fast as posible put the other pipe (modified one) and datalogg again. See the changes in AFR and the time it takes from say 1500rpm slam!(pedal to the metal) up to 7krpm.
Compare results. If Ve has improved then AFR should have leaned slightly. If that leaning is too much (13, 13.5 or leaner :1) in the lower rpm (up to around 3500 or 4000rpm) you have to enrich it a bit around 12:1. Keep it at around 12.5 or slightly leaner on the top. You'll notice the sweet spot by datalogging time vs.rpm. Remember to do it as fast as posible in order for ambient variables not to change much and fool you.
Theres also what is called lean spooling that is having your AFR close to stoich in order for EGTs to be high and aid spooling, but of course this is in a certain area of the fuel map (around the cruise and slightly higher load zones) not the full load zones! (even in low rpm).
So give it a try.
Obviously everything has to be up to the task ie. clean injectors, good fuel pressure, good plugs etc etc etc.
 

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Discussion Starter #120
One thing I don't get however is why my boost seems to come in slower below 1 bar - past 1 bar all hell breaks loose. The car actually seems to pull a LOT better at part throttle at low RPM, even though boost seems to be down 0.2~0.3 bars at lower speeds. Could be that I'm using less throttle because the engine is flowing air more efficiently. In other words, my imagination.
If the car is coming up sooner, might be in a different box in the map. If you are 2-3-4 degrees off, it might feel slower. You will often feel this as it will feel better at low throttle as you normally get more timing, have more timing in those areas of the map.

On Josh's car, small turbos, and 19psi the response was the same or a little better, and power at the top was higher. I only did back to back testing on one car, but I know how much smoother, and how much less surge the big 2860-10 car feels, and so I am sold on the modified twin turbo pipe.

 
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