VQ35 Maxima, low boost Dyno.
08-18-2010, 07:37 PM
#1
VQ35 Maxima, low boost Dyno.
For anyone interested to know, I just went to dyno mycar, I went on 11psi however on dyno it showed as 10psi since theres less load (Dynojet). For those that dont know, built short block 3.5, 8.8:1 compression, single Holset HX40 rear mount, Water/Meth injection, and stock timing (about 22deg max).
The car has been misfiring for a few weeks, I have not been able to figure it out till today, this morning before dyno i regapped plugs down to .030 from 035, and still missing. Still dyno'ed, and result was 380whp 366wtq, STD. Not happy but considering the crazy missing, auto, and only 10psi on a 8.8:1 compression, I dont think its too bad. Also I dont have variable cam timing, I am using the VQ30 timing equipment and ecu.
So I went to autozone, alternator is putting out only 35amp, supposed to be 125+, that can def explain the misfire.
I have it as MPH because in RPM the curve is all over the place cuz of the missing.
The car has been misfiring for a few weeks, I have not been able to figure it out till today, this morning before dyno i regapped plugs down to .030 from 035, and still missing. Still dyno'ed, and result was 380whp 366wtq, STD. Not happy but considering the crazy missing, auto, and only 10psi on a 8.8:1 compression, I dont think its too bad. Also I dont have variable cam timing, I am using the VQ30 timing equipment and ecu.
So I went to autozone, alternator is putting out only 35amp, supposed to be 125+, that can def explain the misfire.
I have it as MPH because in RPM the curve is all over the place cuz of the missing.
08-18-2010, 07:52 PM
#3
tonight I got on the gas and didnt feel any misfires, now that I put in a new alternator. Hopefully this one last longer, damn autozone parts FTL.
Once I make sure the misfire is gone, im going to up the boost to 17-18psi, and take off the muffler. Removing the muffler alone increases boost about 3psi and spools quicker too. (Dynomax superturbo.)
Last edited by streetzlegend; 08-18-2010 at 07:55 PM.
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08-19-2010, 11:36 AM
#11
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is that a twin scroll? If it is you could use a quick spol valve. What are ur power goals? You might be better suited to ur curve. That turbo should put you up to 600hp so if ur only going for 500 I'd drop it down. Sweet and unique setip though.
so removing that short of a muffler increases boost that much? That must me a crazy restrictive muffler.
so removing that short of a muffler increases boost that much? That must me a crazy restrictive muffler.
08-19-2010, 11:46 AM
#12
if it was a twin scroll, he'd already have a twin scroll manifold.
I think SP is a little deceptive in their advertising because they are comparing a open manifold/big A/R vs their valve and a twin scroll turbo. Anyone knows that a smaller A/R = faster spool.
They should compare a true twin scroll vs their valve. The only market for the QSV are people that cant swap their manifold (ie inline 6 people, a twin scroll on a V motor is easy to make as seen in Jtran's build)
also 3 psi is not much. SP gained more than that by dropping their 3" true dual.
I think SP is a little deceptive in their advertising because they are comparing a open manifold/big A/R vs their valve and a twin scroll turbo. Anyone knows that a smaller A/R = faster spool.
They should compare a true twin scroll vs their valve. The only market for the QSV are people that cant swap their manifold (ie inline 6 people, a twin scroll on a V motor is easy to make as seen in Jtran's build)
also 3 psi is not much. SP gained more than that by dropping their 3" true dual.
Last edited by str8dum1; 08-19-2010 at 11:50 AM.
08-19-2010, 01:16 PM
#13
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if it was a twin scroll, he'd already have a twin scroll manifold.
I think SP is a little deceptive in their advertising because they are comparing a open manifold/big A/R vs their valve and a twin scroll turbo. Anyone knows that a smaller A/R = faster spool.
They should compare a true twin scroll vs their valve. The only market for the QSV are people that cant swap their manifold (ie inline 6 people, a twin scroll on a V motor is easy to make as seen in Jtran's build)
also 3 psi is not much. SP gained more than that by dropping their 3" true dual.
I think SP is a little deceptive in their advertising because they are comparing a open manifold/big A/R vs their valve and a twin scroll turbo. Anyone knows that a smaller A/R = faster spool.
They should compare a true twin scroll vs their valve. The only market for the QSV are people that cant swap their manifold (ie inline 6 people, a twin scroll on a V motor is easy to make as seen in Jtran's build)
also 3 psi is not much. SP gained more than that by dropping their 3" true dual.
he wouldn't "have" to have a twin scroll manifold. Look at PL kits. They come with twin scroll garretts and it's a single scroll manifold therefore if room permits they would be able to take advantage of a quick spool.
and jtran didn't gain anything with a twin scroll. I don't see how even a divided manifold makes it spool faster. They have essentially the same size turbo as me and they spool slower so i'm confused how putting 6 cylinders into 1 opening is better than 3 cylinders in half and 3 cylinders in the other half.
i DO see the benefit of 6 cylinders into half of the scroll causing it to spin faster though. double the exhaust gases into a small scroll, then opening it for full effect later.
do you mean they gained 3psi from dropping their exhaust off the car? They also had a full length exhaust right? so about 12ft of piping and a muffler. This setup has about 18" of piping into a muffler. Shouldn't be as restrictive as piping the full length of a car so that's why i thought 3psi would be a pretty big gain.
08-19-2010, 02:27 PM
#14
Yeah, my turbo has an 18cm divided housing, but I do not have a twin scroll manifold. Its a rear mount setup so a single pipe comes from the Ypipe and into the turbo. A quick spool valve will def help but in my opinion and my budget, SP is out of their mind as far as pricing goes for that. Thats why I got a nitrous kit, still cheaper then the quick spool valve LOL, and far more effective.
My goal is to be near the 500whp mark with unlocked converter. Since I have read on here of the HR head bolts allowing head lift at aprox 620+ whp, im going to stick to lower than that.
Yeah this muffler seems to be very restrictive, removing it changes up the whole tune as well, since it spools up sooner and increases boost. Alot of the cummings guys like to use 4" exhaust out this turbo, Im not going to do that but I do have a bandclamp holding the muffler. So for track visits, I just simply unbolt the muffler and thats it. I have no cats, resonators, nothing, so for daily driving you can see why I still have that muffler (without it, its loud enough to not hear yourself think) lol.
My goal is to be near the 500whp mark with unlocked converter. Since I have read on here of the HR head bolts allowing head lift at aprox 620+ whp, im going to stick to lower than that.
Yeah this muffler seems to be very restrictive, removing it changes up the whole tune as well, since it spools up sooner and increases boost. Alot of the cummings guys like to use 4" exhaust out this turbo, Im not going to do that but I do have a bandclamp holding the muffler. So for track visits, I just simply unbolt the muffler and thats it. I have no cats, resonators, nothing, so for daily driving you can see why I still have that muffler (without it, its loud enough to not hear yourself think) lol.
Last edited by streetzlegend; 08-19-2010 at 02:29 PM.
08-19-2010, 02:55 PM
#18
Already did lol. This was the original 170K tranny, I have been abusing the crap out of it for years, it finally started to give up after a track visit and doing alot of loading up of the converter and overheated. Now I got another stock auto ($200) but with transgo and the largest cooler I could find.
