Taking a Stock Engine with Stock Turbo to the limit....

[seedling]

Man this is great stuff! Sorry, for slightly off topic question. However, you mentioned a TE44 with .85 housing on your old car. So, I'm just wondering if this made the car lazy or what the reason was for using it?

Thanks!


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[murphster]

Scott what size tires are you running? What are the gears in the back? I'm sure you told this before.

I'm running 3.23 gears on 28" 275/60/15 Mickey Thompson ET Street Radials Pros.

 

[murphster]

Man this is great stuff! Sorry, for slightly off topic question. However, you mentioned a TE44 with .85 housing on your old car. So, I'm just wondering if this made the car lazy or what the reason was for using it?

I don't remember it being lazy. I did have a baby 206 cam, slightly modified heads, and a looser stall converter though. Probably went to the .85 to try and get a little more out of it. Ran mid 11s at 113-114mph and it was heavy at over 3800lbs. That was my old Regal clone that I daily drove.

 

[murphster]

So, I think the plan is to continue to shift around 4700... still seems to lose power above that and the backpressure also goes up. I am going to try and keep the boost at 21psi for the whole run and maximize power there by adding timing and leaning it out a little more.

Almost!

So I got back to the track and did what I planned.... set boost back to 21-22psi, added a little timing to 23#, and leaned out a little to 11.0 A/F. Oh so close.... made my three fastest runs with each run getting just a little quicker. Left harder each time and never spun, 60ft just not getting much better. I think the converter is just too loose for a super 60ft. Set best mphs too.

Tune seems to be really good. I could maybe add a degree or two more but thats about it I'm guessing. I might be able to do some tricks in XFI to add timing just in 1st and 2nd gear, don't know. Here are the slips, I'm 7721:

 

[bison]

Put in a 200c trans with a lockup converter


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[Mr.Spool]

Almost!

So I got back to the track and did what I planned.... set boost back to 21-22psi, added a little timing to 23#, and leaned out a little to 11.0 A/F. Oh so close.... made my three fastest runs with each run getting just a little quicker. Left harder each time and never spun, 60ft just not getting much better. I think the converter is just too loose for a super 60ft. Set best mphs too.

Tune seems to be really good. I could maybe add a degree or two more but thats about it I'm guessing. I might be able to do some tricks in XFI to add timing just in 1st and 2nd gear, don't know. Here are the slips, I'm 7721:


View attachment 305075

Your def there.i must say I am surprised the record is still there only because of how light you are.your slip is really strong for that combo! The back end gains and mph are impressive.The 3.42 and 2.74 1st gear must be more critical for the stock setup than most realize.

 

[murphster]

Put in a 200c trans with a lockup converter

Supposed be some gains since they have low parasitic loss. But prob have to spend some decent $ to get one to hold up and have tbrake, etc.

 

[Pronto]

You should use a "stock" D5 and "stock" 200 trans to keep the "stock" theme lol.

 

[murphster]

Your def there.i must say I am surprised the record is still there only because of how light you are.your slip is really strong for that combo! The back end gains and mph are impressive.The 3.42 and 2.74 1st gear must be more critical for the stock setup than most realize.

I think the light weight helps overcome the drawback of the 3.23s and th400 1st gear. At the same time, the 3.23s help keep the rpms low on the back end. Its not hurting that much as my 60fts are already not too far off from being really good for stock. 3.42s may help a heavier car get out of the hole but at the top end the higher rpm will hurt, and will be worse if the converter isn't locked. With the same slip I'd be almost 300 rpm higher and put me close to 5100 rpm up top (at 4800 now). 28" tires usually hurt a heavier car too at this power level too, so going to 27" tires will only add to the rpms up top. Even going to a locked converter with no slip on 27" tires on 3.42s will put you around 4950 rpm, 150 more than me.

I think that is why you usually see low mph on stock setups with good ETs... A taller tire will give you better mph but will be slower out of the hole resulting in a not so great ET. A shorter tire and a looser converter will get you out of the hole great resulting in a decent ET but a crappy mph since the rpms get so high up top. And something like a restalled D5 on 27" tires will give you a decent 60ft and good mph since the rpms are kept within reason. If you can hit it hard off the launch with E brake, transbrake etc, and lock the converter up top that is the best scenario. But you still won't keep the rpms lower up top than I can with 28" tires and 3.23s..... I can only get away with it because my car isn't heavy though.

A lower stall converter should help me couple at a lower rpm on the launch and after the shifts resulting in a little more torque. I really don't know how much it could gain though as its not like my rpms are way off... maybe 5 hundredths in the 60ft and another 5 hundredths during the run? So maybe there is a tenth to be gained... maybe? But if I just leave even harder on the launch I may be able to chip a couple more hundredths off my 60ft putting me in the low 1.5s. I'm amazed my converter has worked as well as it has though considering its the same one that ran low 9s. I'm getting 6-7% slip up top right now and coupling at 4300 so its pretty damn good.

 

[murphster]

You should use a "stock" D5 and "stock" 200 trans to keep the "stock" theme lol.

If I had a built 200 with a tbrake I would for sure. That would be more money than I have in the whole engine swap back to stock though lol. I know I can launch the TH400 as hard as I want and it will take it no problem, its reverse manual valve body for easy shifts, and has an electric tbrake. To top it off, I traded it even swap for my old 2004R many years ago and never put a dime into it since. Hard to beat.

 

[murphster]

So I've tried varying the boost almost 5psi, changing timing 5 degrees, adjusting the A/F almost 5 tenths, was in weather from the 50s to 70s.... almost all the runs are within a tenth or so of each other. I really haven't improved from the second run I made on May 10 when it broke up a little up top. I may be able to get a few more hundredths out of it hitting it harder on the launch and tweaking the tune... but I don't expect to pick up a bunch. A low 1.5 60ft is going to get me a mid 11.3. I just think that is about all its got. A different torque converter is probably the best chance I have of picking up.

Now.... as far as people saying you can run too much alky or don't run more than you need... I am still running dual nozzles at full blast like I did at 9 sec power level. I am running just a little over 50% duty on my 42lb injectors. I am burning probably close to 30% alky as fuel. Its way more than I need but I wanted to see if there was an advantage to running a high amount of alky when pushing a small turbo. I will probably go over to one nozzle sometime. In my experience, you can run too little alky but not too much!

Here is the XFI log from my 11.403 run, nice and clean.... :

 

[murphster]

here is the same log with Alky pressure and Backpressure turned on with boost. Alky is the top green one and Backpressure the bottom blueish one. Alky is nice and steady and Backpressure reasonable and constant through the gears.

 

[Nigel]

Murphster,
Your MAP says psia, I think it is psig? Back pressure says psi, is that gauge or absolute?

 

[murphster]

Backpressure sensor was originally calibrated from a gauge so I'd say PSIG. Its an aux input from a pressure sensor, you can name it anything you want.


XFI displays boost as MAP (PSIA) but its really closer to PSIG. From the manual:

MAP (PSIA) - The calibrated reading (expressed in pounds per square inch) from the manifold absolute pressure sensor minus one standard atmosphere’s worth of pressure. The standard atmosphere is subtracted to get an approximate gauge pressure reading – i.e. the difference between ambient and manifold pressure – from an absolute pressure sensor. MAP (PSIA) can be used to monitor boost pressure in a format that is similar to the readings from a mechanical boost gauge.

Because the MAP (PSIA) readings are based on an absolute pressure sensor and an assumed ambient pressure, they will vary with actual ambient pressure (which depends on weather conditions, altitude, etc). For this reason, they may differ slightly from the readings from a traditional boost gauge which are not affected by changing ambient pressure.

 

[bison]

I think the light weight helps overcome the drawback of the 3.23s and th400 1st gear. At the same time, the 3.23s help keep the rpms low on the back end. Its not hurting that much as my 60fts are already not too far off from being really good for stock. 3.42s may help a heavier car get out of the hole but at the top end the higher rpm will hurt, and will be worse if the converter isn't locked. With the same slip I'd be almost 300 rpm higher and put me close to 5100 rpm up top (at 4800 now). 28" tires usually hurt a heavier car too at this power level too, so going to 27" tires will only add to the rpms up top. Even going to a locked converter with no slip on 27" tires on 3.42s will put you around 4950 rpm, 150 more than me.

I think that is why you usually see low mph on stock setups with good ETs... A taller tire will give you better mph but will be slower out of the hole resulting in a not so great ET. A shorter tire and a looser converter will get you out of the hole great resulting in a decent ET but a crappy mph since the rpms get so high up top. And something like a restalled D5 on 27" tires will give you a decent 60ft and good mph since the rpms are kept within reason. If you can hit it hard off the launch with E brake, transbrake etc, and lock the converter up top that is the best scenario. But you still won't keep the rpms lower up top than I can with 28" tires and 3.23s..... I can only get away with it because my car isn't heavy though.

A lower stall converter should help me couple at a lower rpm on the launch and after the shifts resulting in a little more torque. I really don't know how much it could gain though as its not like my rpms are way off... maybe 5 hundredths in the 60ft and another 5 hundredths during the run? So maybe there is a tenth to be gained... maybe? But if I just leave even harder on the launch I may be able to chip a couple more hundredths off my 60ft putting me in the low 1.5s. I'm amazed my converter has worked as well as it has though considering its the same one that ran low 9s. I'm getting 6-7% slip up top right now and coupling at 4300 so its pretty damn good.

FYI the quickest pass I ever did on a stock turbo was with 29" Firestone slicks. 1.61.-1.63 was typical. Best of 1.59. Made 17 passes one day in May of 99. The car strong in the 330' and a turd out the back. Race weight about 3450 lbs back then when I was 150lbs. For e.t. Purposes it's more important to get it to leave hard and stay in the power band when the car is moving slow


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[murphster]

Figured the 29" would hurt 60ft more. Finally caught up to it with the taller effective gear though. That was a nice race weight.

 

[Nigel]

Do you know when looking at exhaust to boost pressure ratio, is it:
Exhaust PSIG/Boost PSIG = Pressure ratio? or
Exhaust PSIA/Boost PSIA = Pressure ratio?

 

[Mr.Spool]

I think the light weight helps overcome the drawback of the 3.23s and th400 1st gear. At the same time, the 3.23s help keep the rpms low on the back end. Its not hurting that much as my 60fts are already not too far off from being really good for stock. 3.42s may help a heavier car get out of the hole but at the top end the higher rpm will hurt, and will be worse if the converter isn't locked. With the same slip I'd be almost 300 rpm higher and put me close to 5100 rpm up top (at 4800 now). 28" tires usually hurt a heavier car too at this power level too, so going to 27" tires will only add to the rpms up top. Even going to a locked converter with no slip on 27" tires on 3.42s will put you around 4950 rpm, 150 more than me.

I think that is why you usually see low mph on stock setups with good ETs... A taller tire will give you better mph but will be slower out of the hole resulting in a not so great ET. A shorter tire and a looser converter will get you out of the hole great resulting in a decent ET but a crappy mph since the rpms get so high up top. And something like a restalled D5 on 27" tires will give you a decent 60ft and good mph since the rpms are kept within reason. If you can hit it hard off the launch with E brake, transbrake etc, and lock the converter up top that is the best scenario. But you still won't keep the rpms lower up top than I can with 28" tires and 3.23s..... I can only get away with it because my car isn't heavy though.

A lower stall converter should help me couple at a lower rpm on the launch and after the shifts resulting in a little more torque. I really don't know how much it could gain though as its not like my rpms are way off... maybe 5 hundredths in the 60ft and another 5 hundredths during the run? So maybe there is a tenth to be gained... maybe? But if I just leave even harder on the launch I may be able to chip a couple more hundredths off my 60ft putting me in the low 1.5s. I'm amazed my converter has worked as well as it has though considering its the same one that ran low 9s. I'm getting 6-7% slip up top right now and coupling at 4300 so its pretty damn good.

Think Ed brewer was on a 26 tall tire and a slick with a 12 lockup on his car the taller tire slowed him down.i also just think the stock setups with the stock turbos just fall off on the back end because the turbo is only good for so much air and horsepower keeps you there torque gets you there.i am totally surprised that the converter is working as well as well as the twin nozzle setup that you run low9s with its super interesting to me.i run high %s of meth on my car right now and it runs great.i understand what your saying about the gear and Rpms but I wonder if you geared your car a little more aggressive and dropped the 60ft into the 1.4 s and let's say it lost 2/3mph if the trade off would be worth an overall et drop.

 

[murphster]

Do you know when looking at exhaust to boost pressure ratio, is it:
Exhaust PSIG/Boost PSIG = Pressure ratio? or
Exhaust PSIA/Boost PSIA = Pressure ratio?

Everything I've read refers to PSIG. And like I said before, even though XFI labels it PSIA its really gauge pressure referenced to standard atmosphere. Only time I see absolute is when looking at the tuning tables that have kPa on one axis.

 

[Nigel]

Everything I've read refers to PSIG. And like I said before, even though XFI labels it PSIA its really gauge pressure referenced to standard atmosphere. Only time I see absolute is when looking at the tuning tables that have kPa on one axis.

Thanks for the info!