Making the switch - supercharger to turbo

[No Tread TommyG]

Ordered the kit last week from Wayne Presley.

Vortech V2SQ system 90% removed, going to the classifieds shortly!

Single Magnum T-70

swapping the 3.27's for 2.73's (C4)

Really curious what how this converter will handle the change, might have to re-flash.

Looking forward to some sick torque

More to come.....

Tom

[2fastCobra]

Way to go, I have used many different types of superchargers and while fun they just can hang with a properly set up Turbo system. No more belt slip!!!

[Cobra 302]

I'll be watching your progress. I want to go twin turbo at some point.

[No Tread TommyG]

After receiving the kit, it wasn't quite what I was looking for and decided to go a different route, relocating the turbo with a new hotside.

The unused original hotside portion is for sale in the classifieds if anybody's interested in picking one up very cheap.

First start:

First start Magnum T-72 - YouTube

First start Magnum T-72 - YouTube

Took for a spin, runs very smooth, was able to footbrake to 2500 and lite the tires. Cruising in 3rd I didn't boost it more than maybe 3 pounds till I get it tuned but even there I could feel the torque coming.

I switched my gears from 3.27 to 2.73's. Can't even tell with the extra torque.

LOVE the deep thoaty sound. Quieter too which I prefer.

Tom

[2fastCobra]

What turbo did you go with? You are going to like all the extra torque!!! Post some pictures when you can.

[No Tread TommyG]

I ended up with a Magnum T-72 per Magnum's recommendation. .81 a/r Q-trim T4.

Still have some tidying up to do, will get some photos out soon!

[No Tread TommyG]

Snapped a couple shots, didn't get a close up of the headers before going in. We're using the wider bolt holes on the heads/flange, header bolts and plug access is great.

Hope to hit the dyno the week of the 15th.

[Edward B]

Nice install! Can't wait to see what it does compared to the supercharger. Will you run the same boost level, or more? :-)
Ed

[No Tread TommyG]

Thanks Ed.

Shooting for close to the same psi, maybe a tad less.

[No Tread TommyG]

Wouldn't have believed it if I hadn't seen it.

Interesting dyno (Dynapack), wheels get pulled off, dyno bolts to axles, see pic. Never seen a dyno load a car like this, seemed more like an engine dyno.

This was in 100 degree weather, San Fernando Valley. Previous dynos were near the beach, 70-75 degrees, almost sea level, and on a Dynojet.

Before with blower:
520 whp
477 wtrq
14psi

Now with turbo (and lovely hot air):

548 whp
736 wtrq
15psi

he was very conservative with the timing (10+15) and AFR (11.0)

There's more in it but this took most of the day, we decided to stop there this time around.

On the street, feels like a missle. From a roll in second (remember I have an automatic C4 with 2.73 rear gears), squatted, spun and bolted. That was at 3/4 throttle, backing off to 1/2 when the tires lit up. Shifted into 3rd way early, engine didn't even know the difference from 2nd to 3rd, just kept squatting and spinning.

Good thing I put on the power brake kit!

Tom

[Thomas W]

Sounds great Tom. I've had big block cars, nitrous cars, blower cars, and turbo cars. For me, there is no substitute for a well set up turbo car. Cheers.
Thomas

[No Tread TommyG]

Thanks Thomas. Time will tell if/what tweaks I have to make.

I meant to ask you, when you're running down the dragstrip, are you peddling to control tirespin or are you able to matt it to the floor?

Tom

[Thomas W]

On the street 1st gear is peddle, 2nd gear is peddle half the time and the other half it fully hooks, 3rd always fully hooks. At the strip I only hook in 3rd because the track I go to once a year is non-prepped and more slippery than most streets (hence no 9 second slip yet). Cheers.
Thomas

[MJN]

No doubt the power gains are impressive but there is something really screwy with those charts, no way that the curves can go vertical or even backwards like that instantaneously at 3250 rpm and then why would the torque fall off steadily from there?. Typically the torque curve would stay somewhat flat. Is your wastegate plumbed in correctly?

Where's John Card when you need him?

[No Tread TommyG]

Wow Thomas, the track is worse than the street?! Makes sense why you don't have the 9 second slip.

MJN I noticed that too. That dyno was like no other I've seen. I believe it looks like it goes backwards because of how it operates. At 3200 or so it hangs, it bears down hard on the car, actually keeps it from passing a certain rpm at certain stages, probably pulled it back a tad in the process. I'm assuming this is where the high torque numbers came from as well.

It is also possible that the rpms are based off of wheel/axle speed as apposed to engine rpms, not taking into account converter slip. What was on the desktop screen (dyno) vs. the laptop (connected to engine harness) was different. The pull actually went to 5300-5400 rpms per the laptop playback.

[No Tread TommyG]

Dynapack technical intro

And so it occured to me that the rpms on this dyno sheet go about 500 off (low) from the 3300 mark where it goes straight up.

[John Card]

Originally Posted by MJN

No doubt the power gains are impressive but there is something really screwy with those charts, no way that the curves can go vertical or even backwards like that instantaneously at 3250 rpm and then why would the torque fall off steadily from there?. Typically the torque curve would stay somewhat flat. Is your wastegate plumbed in correctly?

Where's John Card when you need him?

Here I come to save the daaaaayy!!!

Sorry guys - I've been super busy and just got a chance to check in.

That's an odd chart for sure, I'd really like to get a copy of the original Dyno file to have a closer look, but it looks like a couple of things could have happened. Did the trans downshift? That would explain the slight decel and the torque jump. Also, slipping converters combined with turbo lag and waste gate controllers can do odd things - in a situation like this, the Dyno is trying to actively adjust the load to maintain linear acceleration and once in a while the interaction of all of those things at the same time can lead to some strange data spikes. If you can send me the original Dyno file I can open it and probably learn more. I'd also like to see the test (control) settings, as there may have been another way to conduct the test that would have worked better for you.

[John Card]

Also - the likely reason why the rpm was off is due to converter slippage, and the Dyno measuring rpm at the axle.

[No Tread TommyG]

Yup, axle rpm. No downshiift.

Don't have the dyno files. I wonder if they'll give them to me.

[2fastCobra]

I told you the torque would be unbelievable!!!!

[No Tread TommyG]

Now I'm nearly convinced I'm at the wrong tuner. It took nearly 7 hours to get this far (same tune as other chart).

The A/F is 15+ from 2250-3000 rpms, going as high as 17!

This is rolling into the throttle going to WOT.

The problem I'm having on the street is right in that rpm range, pops, sputters, eventually goes pig rich and runs like crap spitting raw fuel out of my sidepipes.

Thinking about heading back to my previous tuner. Thought I was doing the right thing going to a load bearing dyno but this doesn't look right to me.

Let'r rip

Tom

[MJN]

What engine management system are you using? If it's not set up for boost (very high VE) perhaps that could be part of the problem. But I agree that it appears the tuner is a little lost.

[NiceGuyEddie]

geeze louise Tommy!

how much faster do you want to go?

[No Tread TommyG]

Mike,

Stock 1993 computer with programmable Diablosport chip, same management I ran with the blower for the past 9 years. The tuner and dyno are different : )

Hi Eddie!

Warp + 2

[MJN]

Tom.

I don't think the Ford EEC does a good job of supporting a blown engine package. I have been fighting a light throttle high rpm miss for a while now and can't figure it out using a TwEECer R/T. It happens while rolling into the throttle coming out of sharp Auto X turns at 3000 or so rpm and it is really frustrating. The blower is building boost but I can't get the EEC calibration to support it, so I am changing to a custom Megasquirt controller packaged in the Ford EEC case programmed with Tuner Studio. It's virtually plug n play. I won't post links here but search for Megasquirt Pimp and you will find a bunch of info. I have the unit sitting here but haven't had chance to install it yet, I'll let you know how it works out when I do. At less than $700 it seems like a very good option.

[Thomas W]

Mike, I have the stock Ford computer with an SCT chip and it has ran perfect for 5 yrs now, despite changing turbos a couple years ago.

Tom, are you absolutely sure you don't have an air leak on the cold side plumbing? Any debris on your MAF?
Thomas

[No Tread TommyG]

I too have ran that computer and chip for 9 years with the blower with no issues, ever, until now, with the turbo and this new tuner and dyno.

I triple checked the cold side for leaks, haven't checked the MAF.

Now that I'm looking at the A/F ratio chart, I can't believe he let me drive out of there with the following stats (I can't believe I didn't see it myself):

17:1 A/F at 6 psi
15:1 A/F at 9 psi

Is it possible in that range it's going so lean, the computer is going into limp mode?

If I mat it and go through that range, it'll take off like a bat out of hell, it's just in that 2250-3000 where it has the problem.

I think I'm just going to go back to my original tuner, he always did a good job on the car.

[MJN]

Tom I'm not sure this is what's happening in your case but sometimes an overly rich mixture can appear lean because you are actually causing a misfire that is allowing extra oxygen to escape the chamber and fool the sensor. Does the car seem pig rich or does it seem lean?

[No Tread TommyG]

I've never actually experienced a lean condition so I'm not 100% certain of the sympoms, but what I'm seeing is popping during acceleration, no gas smell, and the fact that it's happening right in that range where the A/F on the graph is 15+.

From there it changes, goes pig rich, smells of it and spits black spots out of the sidepipes onto the ground.

[BOB SCHAEFER]

I've never even ridden in a turbo car, let alone driven one....but for some reason I recall you lose the glorious sound of the V8. I can see that with the turbos located in the exhaust path this would be true, but how much sound is lost?

Another issue is losing torque down low and that the turbo car doesn't make good power until you get in the higher revs? Thats one of the things is that my KB 331 makes gobs of power right out of the gate.

A part of me wants to build a twin turbo 408.

Feed back?

Thanks in advance

Bob