DOWN-sized

[BLOWNBY]

OK...Went from a YSi to a aftercooled T?? Long story short. YSi made 22 psi and over 670 rwhp. But low end seemed to be lacking. Maybe I was crazy???Between my s trim dyno and YSi dyno, they were prety much the same in power to 4500 then the YSi pulled away. (s trim and 13 psi 530rwhp)

So far best of 10.32 at 134 with the YSi and MT DR's. Still needed to tune the suspension for better 60'.

Anyway, now have the T trim with the aftercooler(no water yet) and seem to be making a max of 15 psi at 5800. It flashes to about 12 psi instantly then goes to about 15 and levels off.

Now when I am at the track the car will see 6600 rpm's. However, for now the pulley that is on there is maxing the blower out 55,000 rpm's at about 5,800 rpms. I ordered a larger pulley so I will put the T at it's max in the 6,600 range.

Is the aftercooler box robing a lot of boost? I expected over or near 20 psi.
Does it have something to do with the blower being spun so fast at such low RPM's?

Or is this right?

So far on the street it does feel a little better than the YSi considering less psi.

Also is there a point of too much timing. I have initial at 31* and the BTM at 1/2. Since I will be making 3-5 less psi and have a cooler charge temp due to the aftercooler do I add 2-3 degrees of timing :D or is that too much?? I run c-14 at the track.

[connie]

[QUOTE=BLOWNBY]: i just hope u don't have the vortech aftercooler, if u do ditch it. can u say restriction. also 31deg initial timing = too much. please get rid of that btm. that thing will lead to u destroying your engine sooner or later. try this , lock your timing out at 25-28 deg with race gas. now watch your car fly. period. if u want more advise provide me with your phone number or call me at 305-213-2000 and ask for officer booker. thanks, r. booker mdpd

[BLOWNBY]

Hopefully in the next week I can see how the car responds to just the distube and see the 20+ psi. I had a feeling the aftercoller may be a restriction, but thought I'd try and see.

Also like I mentioned Lidio (tuner guy) has the same feelings with the aftercoolers on a car like mine. JUST tune it on race gas and be done.

Again I run c-14 so that is not an issue.

I'll give you a shout when i get a chance.

Thanks

[RSNovi]

I have run up to 28 degrees on my car with 100 octane, 22 psi, and 10.5:1 compression.

[BLOWNBY]

Well the aftercooler is sold. I am now seeing about 18-19psi at 6,000. Looks better than the 14-15 psi was previosly seeing. Problem is at full throtle the car falls on it's face. But 1/2 to 3/4 throttle car pulls hard. Better than the YSi. And this is only 1/2 throttle.

Once I can truly floor it I'd imagine I'll be seeing the 22psi I was expecting. Plus I will pull the car to 6,600 rpm's.

I am getting the car retuned on Wednesday. I will let you know of the numbers. Hopefully I can get to the track on Friday and see the single digit pass I've been looking for on my "Street Car".:D

[93gt]

That things gotta be insane!! (like it wasnt before) :freaks: Let us know how it goes on the track and at the dyno!

[stevieturbo]

Why would the much smaller T-Trim be making more power then the YSi ?

Surely the YSi would be more efficient around that power level, than a smaller blower, nearly maxed out ?

[connie]

for the street, the t-trim works better for my combo. i bought a ysi and went through it all. my 357w makes 747rwhp/719rwtq all under 6800 rpm. i want all my power at a lower rpm and it makes the car more fun to drive. i don't have to rev to the moon. i can't wait to get some track times. looking for at least a mid 9 sec at over 145mph. now if i decide i want a faster time i would maybe move up to the ysi. just remember it is a give and take. a balancing act if u will. u have to spin the ysi with the correct pulleys. r. booker

[BLOWNBY]

Why would the much smaller T-Trim be making more power then the YSi ?

Surely the YSi would be more efficient around that power level, than a smaller blower, nearly maxed out ?

I assumed the same. I had the s- before the YSi. And thought well the T is only a small upgrade and since I have a 351 the extra air flow would be beneficial plus it should be more effecient and have cooler charge temp and more power than the T. YADDA YADDA YADDA. Seems as though I may have been wrong! My S-trim with the small 6.87 and 2.95 pullies kept up with the YSI and 8" and 3" pullies till like 4,500 rpm's. Then the YSI pulled away as the strim started to level off. Also the T is probably underrated as it once was a class race blower if not mistaken.

I know have the T trim pullied with a 3.33 vs a 2.95 on the YSI and appear to be making the about the same boost yet more power. Especially down low. I hopefully will have the hard evidence Wednesday after the dyno and see some solid 9 second passes. Best with YSi and the AOD was 10.27 at 134. Only change will be the T trim in place of a YSI and a larger 3.33 pulley up top as oppsed to the 2.95 on the YSi. I have a 8.6" 10 rib lower as well.

Unfortunatly I won't be able to do a true dyno comparison as well since theYSi was dynoed with a TKO and the T will be with an AOD.

[stevieturbo]

So if I read correct....

You have a smaller T-trim, AND you are spinning it slower than the YSi, and you are making more power ????

This is interesting.....

At what point then would a YSi be beneficial over the T-trim ???

[BLOWNBY]

So if I read correct....

At what point then would a YSi be beneficial over the T-trim ???

Bigger cubes, higher RPM Motor, Big heads, big cam. True race car that spends it's time in the High RPM range 6,000-8,000 plus. Or when the T is maxed out and more is required.

My shift point is 6,200 and i cross the traps at 6,600. Plus on the street I want the power from 3,500 to 6,000. Not 5,500 -7,500.

[BLOWNBY]

So if I read correct....

You have a smaller T-trim, AND you are spinning it slower than the YSi, and you are making more power ????

I am not positive I am making more power at the top but in the low and midrange I should be making more. This is why the T will be better suited for me. I would imagine thought that the T can get me near the same 670 at the rear tire with the 20 psi that it will definitly make.

[stevieturbo]

So, if aiming for say 800rwhp, through a manual, would the T-trim be too small ?

Mine is rather lacking low down, but feels fairly good up top.

I'll be going to a 382 very soon though. And my YSi has taken a turn for the worse. Reading this is making me curious as to what a T-trim could do for me ?

[BLOWNBY]

The t trim will probably be near it's limit at 800 rwhp. But you probably could get 750rwhp or so and have plenty of good down low as well. You will also probably be looking into a cog setup though.

Or with a proper intake and heads and cam the YSi would be better suited for the 800 rwhp. You may sacrafice low end torque to get the high numbers. This is the give and take aspect. That is why the T makes for such a great street blower. Can make gobs of low end and make 700-750 at the top as well.

But when i bought the YSi as it was brand new, I though I may as well give it a try and see how it goes. It seems now many in my situation are prefering the T.

My goal is is streetable car that makes tons of power from 3,500-6,500 RPM and can go mid to high 9's all day long. For me the "T is the KEY" The YSi was sacraficing the low end to make the top end in my situation it seems.

[Pro Stock John]

I think it's more of a function of combination, and pulley combos.