If my opinion makes a difference, I say stay away from more boost. The LT1's stock bottom ends (as mentioned above) probably can't handle too much more. Intercooling will help, but not enough I don't think to keep it safe.

Other than that, one Walboro 255 should handle MORE than enough to keep your fuel pressure good with your setup.

One easy way to have a better E/T would be to take your car to a track at a lower altitude where the air is thicker .

 

With converters, you really do get what you pay for. You can call Precision Industries and ask for the same converter they did for Angie Skinner. It works very well, but will be over $700. Also, PTC converters are very popular in the turbo Mustang world, but I'm not sure if they're familiar with STS style turbo's.

Mike

 

Yeah, don't give up on it by any means! New setups don't just run blistering times on the first outing. We beat the living crap out of Angie's car testing the STS kit for a solid week before taking it to the track. First time out was very dissapointing to say the least. On stock converter, tranny and 3.42 gears it went high twelves vs the low 12's it ran on motor alone. Did run some better mph though. We discovered the tranny was hurting from all the initial pounding. Had it rebuilt and installed an approximate 3000rpm converter from PI. First trip back to the track netted a best of 11.7's in the heat at 119mph. That was with full weight. With slicks and skinnies and stallbreaking the converter, Angie netted her best times of 11.13 at 122mph. The car has a 100kmile stock engine with long tube headers, 3" p-pipe, underdrive pulley, 3000 PI converter, 3.42 gears, and the STS kit making either 5 or 6psi(can't remember). You car is making good power, you just have to figure out how to get it to the ground properly. Fuel pump is not an issue. A single 255 pump is good for power well over what your making. Good luck!

 

Also as Mike suggested you do get what you pay for on a torque converter. We absolutely love the PI converters. They always give outstanding results and you can't beat the 2 year warranty with one free stall change. Key on your car is trying to get the turbo spooled some on the launch. Turbo's make a ton of torque, remember!! That 450rwtq yours made is awesome, just have to use that on your launch!! Hold on when you do!!!

 

Dont let anyone try to tell you to get a 2000-2500 stall converter because its a "daily driver". This is a turbo car remember i would prolly reccomend a 3500 or higher stall. some of the grand national guys i know are running 4200's on street cars. Unless your pushing it its not gonna slip that high on the street. Get a tranny cooler and a nice high stall converter and u will shave atleast .75 off your et. You need to launch that thing in boost.

 

Thanks guys. I'm not giving up on it but I don't have a lot more money to put in either. I'll call PI and ask about the 3000RPM converter. There are only a few test and tune nights left this year anyway so I'll play around and see what it can do with the converter and D/Rs.

Dave

 

yeah i dont think the t70 at 5.5 psi is even in its efficiency range

 

I highly recommend you talk to Jack and ask him for the same converter he did for Angie. Telling him you want a 3000 will probably get you the wrong converter. He knows Angie's car well and will know what you're talking about when you call.

Mike

 

agreed.. I was able to squeek out 514rwhp 570rwtq on a single 255hp walbro.. she was getting lean towards the end but I know you aren't out of pump or injectors..

as for the slow spool.. it has been noted on here that wrapping your exhaust will help this considerably and isn't all that expensive to do. may give that a try for better spool.

how about your tuning.. how are you controlling your engine? stock ecm? tunercat or ????

the stall will definately help harness that new power from boost on launching.

do not give up the water injection, what kit is it? is it the STS meth intercooling kit? if so make sure your running meth and water. at 6000 feet I think with proper intercooling and monitoring your IAT's you will be able to run quite a bit more boost then the rest of us down here at sea level. I would say that high up with the thinner less dense air you could push closer to 10 pounds safely as long as your IAT's are kept in check and your fuel stays fat enough. what kind of timing are you running? so many variables to iron out on such a drastically new setup.. as stated above you will begin to work each of the little bugs out gaining nice performance increases at every step.. the stall is a good idea, but I would make sure that EVERYTHING else is address before I went and put the new converter in.. this way your reaping the full benefits of the new setup before you gain the launch. the MPH shows significant power increase from stock and if the car can get off the line the ET's will begin coming down.

my first few 2 weeks of test drives were so drastically different on my front mount setup that I was not sure what to think.. now that I have worked out the kinks of most of what was coming up, the power is much more consistent and tuning is becoming much easier getting everything where it needs to be.. don't give up on it... you will love it when all is finished and working as intended...

start with keeping that heat in.. your at such a disadvantage running so high up that you need every benefit you can get.. it will make leaps and bounds of difference. also double check for ANY leaks pre and post turbo.. these will make a world of difference in the way she spools early in the rev range.

keep us posted!

Chris

 

Guys,

Thanks again for the suggestions. I understand not having a total performer right away but I was hoping for better.

It was just getting lean, not running out. He said the secondary system would be good for future HP gains and wouldn't hurt now.

I'll try wrapping the exhaust. Like you said, it can't hurt and may spool faster.

Tuning is still handled by the stock computer with his tune from the dyno.

I saw the converter listed on the Thunder Racing page. I'll probably order one. Does anyone else have input on stall speed? I've heard 2000-3200RPM. I'm leaning toward the 2800 that Thunder has one their car.

The sticky tires will go on this week. I'm sure I can spool higher without spinning at the lights but I'm a little concerned about the life of my transmission, drive shaft and rear end.

Thanks again,
Dave

 

I had a Vortech S-Trim kit on my '94 LT1 Vette. It ran 12.8 with just the kit and completely stock. I made a new intake tube, and it ran 11.9. And when I say completely stock, I mean that literally other than drag radials: no other bolt ons or changes, no converter, full factory exhaust, not even an adjustable fuel regulator.

As for boost, with the new intake tube, I managed 11psi, and no intercooler. The motor lived for quite a long time until an unrelated failure. Boost doesn't kill motors, detonation or being lean does. Avoid those two, and an LT1 can take 10psi without issue. The problem is that once most people get to that boost level, they have more timing than the LT1 can take at those pressures or not enough fuel.

In your case you really do sound traction limited. 101mph is worth a lot more ET. My sixty foot was just under 2.0, which is where you should at least be.

As for the extra fuel pump, is that a guess or based on some data? Did it check fuel pressure or air-fuel ratio to determine that need? If so, let him do it, as it will be a huge improvement and save your motor (lean is bad).

If not, he really shouldn't be throwing parts at the problem without some reason to base it on.

 

With the boost, you will eventually wear the rings out, no matter how good your tune/fueling is.

You've obviously never been to bandimere speedway

 

Yeah, Bandimere is a tough track. Even the pros that were through a few weeks ago for the Mile High Nationals commented on it. The altitude and temps just get the best of your motor here. I know most people were running nearly a second faster on their stock setups but not here.

 

Which is true of any motor without boost, from lawn mowers to blown LT1s. How much the acceleration of wear is, I don't think anyone has any good data for.

I'm talking about breakage, not wear. But yes, I agree all motors will eventually wear out, and it will be faster with boost, nitrous, a better cam, or more time spent at WOT.

 

I dont think you understand. With boost you NEED to get a HIGHER stalled converter than a 2800. Don't puss out on this or I promise you will regret it. Get a good brand (PI, Edge, Fuddle, Midway) and you will be perfectly happy with a 3600 or so on the street. Remember, it is a lockup converter, so it will have most of the same characteristics as a stock converter, but when you hit it, bam you're in boost immediately and you're gone...