Old TPI setup: 14.4 @ 94MPH 2.0 60'

Modifications since then:
Stealthram
Rebuilt 700R4 with 2800 9.5" converter
cam 234/244 @ .050

Both runs were done with: <b>2.73 gears, 28" tall tires (read: 2.42 gears) </b>
234CFM @ .500 lift heads (edel rpm)
both runs done with nearly same tune...

Ran a 14.4 @ 105MPH 2.06 60' time
blind tune (used TPI tune with 10% extra fuel than before)
Running out of injector and going lean @ 5800 rpms
feels like im floating the valves too..

The cam was temporary just to see what it would do. this week a roller 224/224 @ .050 (.503 lift) single pattern roller is going in, in preparation for the turbos. Driver side manifold is almost finished.

 

How can you go 105 mph with a 2.06 60ft and only run mid 14s?

Is it spinning after the 60ft mark?

 

Nope, zero tire spin. even if i powerbrake it, i barelly get any tire spin. they are 275/60/15 tires, backed by a 2.73 gear. (same as 2.42 gear on 255/65/15 tires because of height)

the first 4-5 seconds of the 1/4 mile is very slow, it doesnt start moving until about 4500 rpms, and with that bad of gears, even with the stall, it just sits and dies at about 2800rpms for 4-5 seconds until it gets off the converter. by that time your already doing 45MPH+

 

2.73 gears

 

nice mph improvement.

 

How much convertor are you running?

Nice MPH BTW!

Charlie

 

2800 Stall, but with the TPI it was consistently 3200~stall I suppose from the massive amount of torque. Now it stalls right where I originally expected it to... 2800RPM. problem is, thats still not in my powerband for the first 5 seconds of track lol...

 

Sounds like a combination of low gearing and needing to work on the tune. That thing must be flying once you get rolling good, to get that high a mph with such a low 60'.

I can picture it like the modified turbo diesel trucks I have seen race. They bog terrible off the line, but come 40 mph or so they take off and nail a high 11 in the 1/4

Why the tall tires/low gear config?

Keep up the good work, and let us know how it is once you get the cam and tune dialed in.

P.S. On my new setup on the 305, I have the top 3 rows in my 1st maf table maxed out, and I'm still very lean at idle. I need to learn how to play with the scalars better so that I can get my resolution back on my table 1 and start to modify part throttle, then work up to max throttle tune. I can imagine that if you have a 350 or better you'll be that much worse off currently.

I'm using the ARAP 6E bin and definition files.

 

Im using the commander 950 to tune, but that cam isnt even in my motor anymore as of today. Im retro fitting a roller turbo cam into it tommarow...

because im installing turbos this week
I wasnt concerned with tune or track performance, I just wanted to get a run in AS IS with the stealthram just to SEE what it could do over the TPI with my mods and no tuning.

I also G-teched it this week, and ran a 14.2 @ 107MPH out back. I then removed the rubber boot connecting the TB to the Air Filter housing, and G-teched a staggering 13.4 @ 110 with that simple change. I guess its pretty restrictive and all, it still contains the old paper air filters it had when i pulled it from the junkyard. Yes, I know, $2 a piece at pep boys... Lazy i guess... but what the heck. the difference was amazing off idle, it actually spun the tires this time... who knows what it would have done with tuning.

Just so everyone knows, I did feel a large drop in mid-range torque (very noticable with the 2.73 gears) going from TPI to Stealthram, But I also went from (218/224) cam to a (234/244) cam so thats quite possibly the reason. The difference in torque was VERY large however...

check the power-adder board for how im doing on my twin turbo setup. Im starting from scratch and welding/cutting everything myself to make it as affordable as possible. Reason for 2.73 gears: Too cheap to buy the tools to install the 3.42's and Carrier I have sitting on my bedroom floor. sigh* I dont suppose Ill need gearing with 2 turbos though...

 

I'll definately have to check that out on the power adder board. Since you mentioned budget turbo setup, are you going to run dual T3's?

I was going to run the same setup a couple years back, but never took off with it. Would you believe that the huge yard over here doesn't stock ANY of them???

Anyways, good luck with it. I'm very interested in seeing how it turns out

 

https://www.thirdgen.org/techbb2/sho...52#post1844452

Actually running dual syclone turbos.... from the compressor maps I have seen they are more efficienct than T3's at higher Pressure Ratios... and support about the same horsepower as a GN turbo which is a T04 I think.