customblackbird

iTrader: (2)

Thinking the 11.5:1 would be better? Also a slow roll 0TPS to WOT your saying keep it in 3rd at say 30mph and mash the pedal while logging?

ddnspider

iTrader: (26)

That would seem reasonable with enough margin. As far as spool, its always going to depend on throttle, gear, and load. In general, pick a gear where you'll have traction, and a reasonable start speed so when you floor it you can see boost from, say 1500 to redline.

LILHEMI

i never like to see anything over 11.7:1 even on c16. but i like to play it safe. on 50/50 meth you should keep it around 11.3-11.5:1.

stevieturbo

Absolutely no reason why that cannot be achieved, especially with a turbo. They alone help quieten things massively.

But more to the point....why make claims of slow spool, yet it blows the tyres off early ? So he wants faster spool to what ? blow the tyres off even earlier ?

It really doesnt sound like an exhaust is a problem.

ddnspider

iTrader: (26)

Im not saying it can't be done....I think it's pointless. If you want to accelerate fast with no noise, then buy a Tesla.

More on topic, the smaller and longer the exhaust, not to mentioned more muffled, the more back preasure which will only hurt spool. The ideal solution was already mentioned....full exhaust that is quiet, and then a cutout.

CyberGrey Z28

iTrader: (4)

Yes, 3 inch single, resonator in the I-pipe, full 3 inch catback and I've got a cut out before the resonator just in case I want to bypass the exhaust. It's really quiet and unassuming, I hear sewing machine noises from the drivetrain

I'm running old 305/35/18 nitto II. They hook with some heat in them at 5-6 psi during 3rd gear rolls(low rpm). Once I go over that 7 psi I have to datalog in 4th gear.

I noticed that in 1st and 2nd gear sometime I don't hit target boost because of traction loss, pedaling the power.

On a slick I hit my target boost even in the early gears as long as I stay WOT.

I'll try and find some logs from my old pc.

stevieturbo

LOL....only a fool thinks a turbo car needs to be stupidly loud to go fast.

So how much backpressure does he have and at what point during spool where there is negligible pressure difference.....does that become detrimental to spool ?

Game ova

Many of the fastest turbo cars I've seen.....were also some of the quietest. Quiet to the point that next to one of those loud for no reason....painfully slow bracket cars, couldn't even hear them.

47ford

ddnspider

iTrader: (26)

Only a fool makes random statements with no data to back it up. I had a 3" downpipe to a 3.5" overaxle exhaust on my turbo setup.....when I opened the cutout off the downpipe I picked up 30whp and spooled 500 rpms faster. Again, I'm not saying you can't go fast and be quiet....it just takes the fun out of it. Same reason I hate recirculated wastegates. YMMV.

stevieturbo

It is comical going to events and having cars making a horrendous racket, then just dribbling up the track. OK yea, some might like a lot of noise and that's fair enough....I'd sooner have performance than noise. But many of them honestly believe that the noise is making them go faster and it has to be that way.

Build the exhaust right and you can have the best of both worlds.

And whilst it may not be a problem over there....when the venues you have to race are strangled by noise restrictions or face closure....again you have to develop things to meet both criteria. Although it really isnt difficult.
But again, the turbos help massively there anyway. It's easy to make them pretty quiet without any negative effect on performance at all.

Game ova

Car I filmed a few weeks ago. Has no exhaust whatsoever, is fairly quiet.... but will run out of your life.

007FJ

iTrader: (28)

Game ova

One more example of a good running car that literally has no muffler, but is very quiet considering how it runs. OP, if you want to run full exhaust.... you're going to need a cutout to help with the spool up.

ddnspider

iTrader: (26)

1st car was way louder than expected.....2nd car was way quieter than expected LOL.

Forcefed86

iTrader: (4)

If you can't go WOT, it's completely pointless to try and test boost threshold. Your AFR and timing look fine to me for low boost. If you plan to keep your current boost/power levels, you're exhaust should be fine as well IMO. Change your gearing and/or get a better tire. Boost will come in faster with more load on the engine. If you are spinning that bad now at half throttle... why are you working to improve the spool?

I agree that hot-side sucks a big one. You could cut out some flat stock and make a 3' to 2" reducer cone easy. You'll have more clearance with the smaller piping anyway. Think I remember the runners on those manifolds are also goofy large for the typical street build.

But I do get it. Quick and easy install and it makes boost! So can't complain too much about a china turbo kit. Wrapping that thin SS usually causes cracking in my experience. Best of luck with it!

customblackbird

iTrader: (2)

Drove an hour to look and pick up the used MT streets 305/35r18s and the seller didn't see a huge dry rot crack around the edge almost all the way around. He was running them on 8.5 rims and it was stated a minimum of 10" rim. I have 9.5s and thinking about running them anyways. Either that or look into a 275/45r18 or 285/295. Either was it was a giant waste of 2.5hrs of my time lol. Looks like I'm just going to have to buy new.

Thanks for the responses guys. Its not that I dont feel spool, car pulls hard but I cant get traction so it just spins. I agree that I need better tires so that will be my next purchase. I just see videos of people with turbos mash the pedal and then you see the boost gauge jump and hear turbo spool etc. I guess I expect that being such a small turbo on the exhaust side. But maybe it is spooling and thus the boost is just frying the tires but then it can't build more boost so it slowly spools as speed increases.

I do want to keep it quiet, car is much more fun now that it isn't loud. Even if I put the cutout in I can honestly say I prob will NEVER open it... which means its there and might leak or rattle and be annoying. Reason is Slow spool or not the car is still fast to me and I would just leave it be and just deal with the slow spool as i refuse to make it loud. But if i can get it to spool quicker and gain some traction to make it alittle more fun on the street then thats what I will do. This is my first turbo car, i built a turbo suzuki 600 and that spooled instantly at 8k 0-12psi and then was gone! I expected this 5.3 with the 76/65 to spool like a switch at 3k and not build boost from 3 - 4500.

customblackbird

iTrader: (2)

I agree, didnt think these tires would not hold up, they seemed to work decent with the supercharger but that was slow to build boost as RPM increases. Going to do tires for sure. Gears are a bit low at 3.55 but they are't going anywhere in this $500 rear end lol. If i get a better rear (custom 8.8 or 9") I would prob step gears down to 3.08s or something. I guess I want to make sure that the system is working correctly... I expected more spool/boost at lower rpms. If backpressure is killing me (not exhaust but the exhaust wheel) then I have a 78/75 VS racing cast turbo sitting on the shelf, but if I dont need it then I'd leave the 76/65. Basically I'm trying to understand why boost is coming in but slow to spool and if there is anyway to correct it without making the car louder. So seems like traction will help, so i'll get MT drag radials. After traction is increased I can see what boost is doing and what else needs to be done.

I saw some steel 3" to 2" vband adapters for like $23 each, the issue is that would push the crossover right into the tensioner. But will it even matter if the rest of the system is still 3" I still feel like velocity will be down on the pass side and up till where it necks down on the driver header. These turbo headers are better than the ebay ones, They have 1 5/8" primaries and not the 1 7/8" primaries with the cheap forward/up ones on ebay. Vbands are still 3" but the tubing is also thicker than the thin ebay crap. I agree it sucks, I checked and called and they said it was 2.5" crossover. I called them after I recieved and had to argue with them that its 3" with a tape measure in my hand... smh. But it was like $1,100 for the entire hot side with turbo so it is what it is for a bolt in affair for the most part.

Thank you and I appreciate your comments.

customblackbird

iTrader: (2)

Ditto, its weird being able to hear the valvetrain in over 10yrs on this car.

Sounds like what I'm dealing with, tire spin in 1 and 2 and going into 3, higher speeds in 3 it will stick at WOT and 4th. I would love to see what your logs are showing. looks like I'm going to need to get tires to enjoy the low end boost that i hope its making.

Forcefed86

iTrader: (4)

Boost is load dependent. As soon as those tires start to spin you unload the motor. If you could go WOT and keep the tires planted it will build boost more quickly. If you can’t get the tires planted... no need for quicker “spool”.

Also you are losing a TON of velocity with all the large piping pre turbo. The 76/65 is also a **** poor turbo design. The split between the 2 wheels is too large. You are asking a small exhaust wheel to drive a large compressor. Which will result in slower spool. If you want quick spool you want it the other way around or at least much less than an 11mm split between the two. That said the 76/65 is relatively small for that motor and you have the smaller housing. So I think you’ll be fine at your lowish boost levels.

Another option would be to place a 60mm or so wastegate or boost activated cutout on it. That way it automatically opens and closes.

I get the silent car appeal. I “T” my two 3” down pipes into a single 2” pipe all the way back to a stock 4 cyl muffler. Then have vacuum actuated 3” cutouts on each turbo.