Turbo GT, SVO differences

[93-331-29psi]

I am not new to the Mustangs or turbos for that matter. But I am new to turbo charged mustangs. I noticed in the Tech article pages that there is a considerable difference in HP ratings between the 83/84 Turbo GTs and the SVOs.

83-84 Turbo GT - 140hp
84-85 SVO - 175hp
85.5 SVO - 205hp
86 SVO - 200hp

My question is... what gives the SVO so much more power? Is the Intercooler the only difference or does the cam and computer play a role also? Reason I ask is because I just bought an unmolested 1 owner 84 GT Turbo car and I am not sure 140hp will cut it in the long run. I intend on changing the timing belt this weekend as it just hit 100k. While I am at it I am thinking that I may want to swap out the cam/followers, but what cam should I use and what else is required with a cam swap? Thanks

 

[kiddiccarus]

Ok, lets look at this against my 1995 V6 Convertable at 150hp stock 2.73 gears T5 trans 7.5 rear.

you have a 84 GT running 140 Hp stock.
3.73 gears in a 7.5 T5 trans (guys am I right on this car?) well considering that you can run 300rwhp on the 7.5 housing and the 3.73 gears are right on the money for this car you are already ahead. Take off the t-3 and slap on a hybrid t-3/4 and an intercooler & header combo (Stingers) and you are on the road to having a beast under the hood.

Stock is only a suggestion that Ford made for us, none of us listened to it, we make it better.....

 

[stackz]

I am not new to the Mustangs or turbos for that matter. But I am new to turbo charged mustangs. I noticed in the Tech article pages that there is a considerable difference in HP ratings between the 83/84 Turbo GTs and the SVOs.

83-84 Turbo GT - 140hp
84-85 SVO - 175hp
85.5 SVO - 205hp
86 SVO - 200hp

My question is... what gives the SVO so much more power? Is the Intercooler the only difference or does the cam and computer play a role also? Reason I ask is because I just bought an unmolested 1 owner 84 GT Turbo car and I am not sure 140hp will cut it in the long run. I intend on changing the timing belt this weekend as it just hit 100k. While I am at it I am thinking that I may want to swap out the cam/followers, but what cam should I use and what else is required with a cam swap? Thanks

the intercooler obviously helps but the computer is where most of the kick comes from. better timing/fuel maps. oh and um....also, your car has the inline intake with the small vam and 30lb/hr injectors. They changed to the square intake, large vam, and 36lb/hr injectors for the later cars which gives you that 175 to 200+ hp jump.

 

[93-331-29psi]

the intercooler obviously helps but the computer is where most of the kick comes from. better timing/fuel maps. oh and um....also, your car has the inline intake with the small vam and 30lb/hr injectors. They changed to the square intake, large vam, and 36lb/hr injectors for the later cars which gives you that 175 to 200+ hp jump.

I actually just discovered this intake difference shortly after you posted (Thanks by the way) and I have a newer square intake sitting in the garage from a 93 2.3 that I kept after the 5.0 swap. This should work right? I actually think I have some 36lb/hr injectors laying around also. Either way, is it safe to assume that changing the injectors, intake, and computer will put me at 200hp???? Is an SVO computer a direct swap item???

 

[93-331-29psi]

Ok, lets look at this against my 1995 V6 Convertable at 150hp stock 2.73 gears T5 trans 7.5 rear.

you have a 84 GT running 140 Hp stock.
3.73 gears in a 7.5 T5 trans (guys am I right on this car?) well considering that you can run 300rwhp on the 7.5 housing and the 3.73 gears are right on the money for this car you are already ahead. Take off the t-3 and slap on a hybrid t-3/4 and an intercooler & header combo (Stingers) and you are on the road to having a beast under the hood.

Stock is only a suggestion that Ford made for us, none of us listened to it, we make it better.....

I think the rear gears are a 3.54 or 3.45 for the Turbo cars this year. I read that somewhere anyhow. I will have to check the tag. The other info provided sound great, guess I know how my tax refund is being spent!!! GRIN

 

[RustBucket]

The 93 intake won't work. The lower half won't clear the distributor. You'll need the upper and lower from a pre-'91 Mustang or pre-'89 T-Bird, SVO, Merkur etc.

 

[kiddiccarus]

Whoa, it will work IF you gut and rotate it. I suggest you www.40bob.com if you are going to look at purchasinf an intake upper and lower, hell you can talk to bob and he wioll do almost anything you like to your intake. He has helped me a lot on a header that i have of his.

Here is another link you should read the whole web site on. It is for the Merkur but it is all about 2.3T engines
http://www.merkurencyclopedia.com/ an #1 source we all go by.

I honestly looked for the correct gears for the 84 but only could find this. http://www.allfordmustangs.com/Detailed/349.shtml and it seems that it dont include the 84's at all.....

 

[Stinger]

I wouldn't bother swapping intakes, there is no proof that the later ones are any better than the inline ones...I'm running the inline on my SVO (traps 103.5mph in the 1/4 on the low boost setting).

As others said, between the ecu, air meter, intercooler, and injectors, that is where most of the power is. There was also a cam change but I'd go aftermarket for one before swapping for a "stock" late SVO cam. There is a pretty big problem with old turbo cars not running as much boost as they did when new. Odds are yours will be the same. To get to that 200hp, you'll need to be running 15psi. You could actually run 17-18psi and get 210-215hp to the wheels.

Of course, upgrading the exhaust to a high flow 3" unit will get you another 30+hp and an adjustable boost valve ($45) will get you much less boost lag and make the car even faster...

 

[RustBucket]

Whoa, it will work IF you gut and rotate it.

Whoa, No. It won't. The '93 intake is different from the turbo era intakes. Gutting and rotating has nothing to do with the fact that
1. The bolt holes won't line up.
2. You can't "gut and rotate" the split pair design of the '91 and later upper intake.
3. The lower intake manifold is design in such a way that the runner for cyl #1 sits in part of the space occupied by the distributor on earlier models.

 

[juscuz]

Actually I would say exhaust and intercooler would be my first 2 choices. My car went 14.5@94 om the stock long block. Change over to the LA3 EEC(with a simple repin and add the ACT sensor) turn up the boost and you will be doin alright.

 

[93-331-29psi]

Great information, I will definitely be in contact with some of you about how to do this right.

 

[65ShelbyClone]

what else is required with a cam swap? Thanks

It would seem that valve stem seals are almost mandatory by 100K on the pre-'87 turbo engines unless there is no smoke on startup. Mine are toast at 107K, which really sucks when you live in a smog state.

Its funny, everyone says to swap the computer when you also have to swap the intake so you can use the square-specific knock sensor position and AIC. Modding the EEC-IV actually isn't that involved and unless you can do an LA3 swap for less than $200, chipping is actually cheaper and more flexible(like a middle ground between a twEECer and an LA3). All you would really need for chipping is the ROM values from an LA3 and the bigger injectors/VAM, besides an EPROM burner, ZIF socket, and (free) software.

From what I understand, ALL SVOs came with the big VAM and only '87-88 TurboCoupes did.

As far as what gave the SVO the power it has, alot is in the tune, some is in the intercooler, and a fair bit is in the boost. I dont know about the turbo GTs, but the SVOs have a premium/regular fuel switch. In "unleaded" mode, boost is limited to ~10psi and many speculate that it pulls alot of timing. In "premium" mode, boost is electronically controlled to 14psi and supposedly with more timing. Believe me, that 4psi makes a HUGE difference.

 

[Pro-Hawk]

Its funny, everyone says to swap the computer when you also have to swap the intake so you can use the square-specific knock sensor position and AIC.

Who uses the Knock sensor??


That is one of the first cheap mods you can do to the car. The KS gets all kinds of false information and retarts timming to help save the motor..even if it doesn't need saving.


As for if the sqaures are better than the inlines...there really isn't any dyno proof one way or the other. I sware though that the sqaures are a little better looking at the inlines up close. It's been a few days but I believe it's the number four runner that is very tight on the inlines. It looks good because there is a pice of plastic covering it making it look completely rounded but it's got a kink in it if you pull it off. Also, you can do more with the sqaures than the inlinesd in way of porting them. This doesn't mean just huging them out either.

The EEC, Vam and IC is the main reasons behind the power difference in the GT's vs the SVO's. Also, the 85.5/86 SVO's and 87/88 TC's came with 35lb injectors while the rest of the 2.32T's came with 30lbs. Now some of the Merkurs came with 35lbs also but not sure on them or if all did. The 30lbs are green tops while the 35lbers are brown tops. So if you plan on doing a PE or LA3 type swap or Zif program, you need the brown tops to go with it. By the way if you do go with a Zif type set up, get a PE program...it's more aggressive tune...they used that EEC in the 85.5/86 SVO. The EEC it's self it probaly 300.00 bux on ebay, so a chip with that tune is probaly cheaper.

**The exhaust mainifold is one thing one should mention...although you don't get any power gains from it unless you port it, you do how ever should get one off an 87/88TC. The older mainifolds crack to easy since they don't have enough meat supporting the turbo near the flang.

 

[65ShelbyClone]

Who uses the Knock sensor??


That is one of the first cheap mods you can do to the car. The KS gets all kinds of false information and retarts timming to help save the motor..even if it doesn't need saving.

That's highly debatable. The crowd at Turboford seems to think the KS has a purpose, even on a stock engine.

 

[Pro-Hawk]

That's highly debatable. The crowd at Turboford seems to think the KS has a purpose, even on a stock engine.

There's some guys I haven't talked with in a while. I trust TurboFord and have actually met a few of them in person. It was JaimeN who helped me do my first tune up on my SVO when I drove down to San Antonio for a Turboford event. I never made it to the track but I had fun hanging out with Jaime all night. Anyways, just click on the linky and check out Stage 1, mod 1 of TurboFords mod list.

http://www.turboford.net/faq/mods.shtml


And here is a quote off TurboFord

knock sensors were put there as a safety mechanism in case someone put in the wrong kind of gas, etc. NOT as a tuning device. if you are relying on the knock sensor to make your tune "safe", then you need to do more tuning.

http://www.turboford.net/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=2;t=041552

Now if you really want to use a KS, the guys on SVOCA has done some research and suggest the later model intakes ( sqaure) gives off the least false readings.

Quote from MikeFleming

In my experiments with attenuating the KS signal (which were about 20 years ago!) the results were that the car was more "driveable" but the power and responsiveness weren't there compared to using the later manifold. But that was a very long time ago.

http://www.svoca.com/forum/showthread.php?t=10388&highlight=knock+sensor