rotary1307cc

iTrader: (5)

figured some looking at either turbo would be curious to see the actual responce time

this is a 370 with good heads, powerglide with tight converter, 3.08 rear gears, E50

take note of the TPS and MAP....... both rolling down the highway in high gear, same timing

gts






pt88

skinnies

iTrader: (33)

Is this on your car?

rotary1307cc

iTrader: (5)

yeah justin it is

picked up 2psi on the same WG setting

the weirdest thing is how much better traction i have on the street, has to be from the slower trasition from the start of positive manifold pressure to full boost

got-a-ls1

iTrader: (12)

seems to be running kinda rich on the 88

rotary1307cc

iTrader: (5)

yeah i bumped my fueling a bit to start and i will bring it back down, fueling is close bringing them into boost though so

and dont pay attention to the differences in injector DC, i have a higher base pressure now than i did with the gts log

9sectruck

iTrader: (9)

is the lag on the 88 really noticeable vs the 76 or just right for hitting the tires on the street

rotary1307cc

iTrader: (5)

well yes on my combo with a tight converter it is quite a bit laggier, if it was looser it may make a big difference, or throwing timing in it which i havent done yet. but yes overall quite a bit less responsive

it does hit the tires much nicer IMO though, my drag radials agree

on the trasbrake with the gts i could be in boost almost as fast as the throttle input.... with the 88 it takes me 3ish seconds at WOT to come up to 5psi...... same timing, same converter

but my converter is tight.... i hit WOT on the brake and it flashes to 2500rpm and has to build boost from there

9sectruck

iTrader: (9)

damn that converter is really tight,,, when you said it was tight I was thinking 3000 3200

rotary1307cc

iTrader: (5)

ha yeah i like it tight like that because i dont have lockup, works good to since i get good coupling down track

1sick-Z

iTrader: (3)

For a street car with a 6 speed which turbo would you prefer?

rotary1307cc

iTrader: (5)

gts no doubt about it

JAX04

iTrader: (17)

Very cool Zac! Sending ya a pm

1sick-Z

iTrader: (3)

I am running the 76GTS now. I love how hard it comes on. The tires dont though. It it more than enough power for me but I was considering a PT88 upgrade if I ever got bored but I believe this is more than enough turbo as well.

Thanks.

Also thank you for the comparison I am sure alot more people were interested in this.

skinnies

iTrader: (33)

Nice, why did you switch? The gts should've been enough for 160+ mph I'd think with your weight.

rotary1307cc

iTrader: (5)

thanks

yeah justin i just dont think the car was back halving right even on lower boost

not sure if it was from the smaller turbine with my higher overlap cam or what, you could just tell on the track it wasn't breathing right

at the track i would shift at 7k and it would drop to 6k on the shift... it would come out hard as ***** in low and then just feel lazy in high... with a good coupling converter too

i would hit 120 in the 1/8 and only 148-149 in the 1/4

see how this one does

rotary1307cc

iTrader: (5)

ohhhh yeah, took it out tonight and leaned it out and maxed my 2 bar OS, yep.... thing is serious and seems to just be getting happy their..... tempt to swap to 3 bar



and worked on the transbrake tuning

works really well IMO now

car was sitting idling in my garage for a half hr after i got done out on the highway while i worked on the transbrake tuning, so that is why the IATs are so high...... but watch what the little bit of meth/water does when it only sprays for a second or two, haha

25* timing, 13.5~ AFR

http://www.youtube.com/watch?v=gdIl6...ature=youtu.be

skinnies

iTrader: (33)

120 to 149 isnt horrible, my rx7 would gain 33-36 out the back door, but we had a soft first half tuneup in it. I think something else was the issue, that turbo should keep pulling for you, probably would've benefitted shifting lower.

rotary1307cc

iTrader: (5)

yes i agree shifting sooner may have helped, i just dont get to the track but a blue moon to see the actual difference

i would loose boost with the gts too

even on that log up above at only 12psi and a max of 6000rpm you can see it start dropping off

at trying to hold 15psi at 7k i am down a solid 2-3 psi, explain that one. what part of the combo is it?

maybe a combo of the good heads and bigger cam

dont get me wrong, i loved that turbo

but this new one is feels waaaay better at 15psi, no drop in boost for me now

9sectruck

iTrader: (9)

have you check back pressure on the hot side with either turbo to see if much difference?
the pt88 is a 80? what turbine vs the gt 76 turbo.
Im getting ready to tackle my car here real soon and im getting worried the pt88 isnt going to have a big enough turbine on a 365..
can you tell your cam specs

skinnies

iTrader: (33)

better boost controller, isn't your car fairly light, I still don't see why the gts wouldn't push it into the 160's, 149 just seems like something isn't right. My ltd at over 4000lbs has been 144mph to give you an idea, on street tires and 95 degree heat.