Damien,

I'm certainly no expert here, but just off the top of my head I can easily think of many, many other parts which are completely different for the VR4 than yours which I didn't see on your list of parts to convert over(i.e. brake system, front & rear axles, AWD system, AWS system, tranny, entire engine is different, etc, etc, etc...) The list of parts that are different between the 2 cars is immense.

I'd say your best bet is to just forget about converting yours over to a twin turbo....it'll cost you an arm and a leg (not to mention the hassle). And even if you were successful, in the end you'd only end up with a stock VR4.....not worth spending that much money on. You're better off just buying a VR4 for the same money that you'd spend converting over....and this way you'd have 2 cars as well.

Just my $.02

 

You can't put the AWD system on a NA. I've asked about this too. The VR-4s are wider, which allows for the AWD system to be put in. It just won't fit in an NA. I think this might be the same deal with the AWS, but I'm not sure. As far as converting, I've heard about a few guys doing this for abuot $8000. Of course you could probably buy a VR-4 for about that much (depending on year...usually 1st gens), but it would save you from insurance. Just a few tips on what's going on with a conversion.

 

ESC,

Are you sure about the VR4's being wider? As far as I know, the bodies are the exact same (with the exception of the VR4s with the active aero n stuff)?

I'm not sure on this one, but check your info with someone else to verify.

 

I see

I just sent $200 for a down payment to double0bondo for the parts below. If i get those i would have no use for them and altogether it was $430 w/shiping. So before i send the rest of the money out to double0bondo I hope he'll understand and return my down payment. I really didn't know it was going to be this confusing just to do the conversion. I don't think i'll do the conversion, what do you guys think of NOS? Is that a better idea? Thanks all for you input...

Parts:
~Intercooler pipes with ALL piping, but you will have to fabricate the rear I/C pipeas the n/a manifold has a secondary butterflysolenoid that gets in the way of the VR-4 I/C pipe
~2 Exhaust manifolds
~Y pipe
~Oil feed lines
~Oil sending unit
~O2 sensor housings front rear
~Thermostat housing as the n/a does not havecoolant line fittings for the turbos
~Coolant feed lines front rear
~Coolant drain lines front rear
~Oil drain lines front rear (custom) as you cannot use the VR-4 ones they aretoo short for the n/a
~Turbo inlet piping going to the MAF meter

 

I was looking at doing this when my engine went bye bye a few months ago. The cheapest way is to find someone with a TT engine that they are willing to sell outright and complete. Drop that bad boy in, and you're more or less ready to go. You'll need a new wiring harness, engine harness, and a few other tidbits. Doing an AWD conversion would be a first, as nobody else has tried thus far. It seems that there are a lot of structural differences between VR4s and base models to allow for the AWD system.

 

I am interested in the same question, That list of parts seems complete, it is everything I can think of, It is also almost exactly the same as the list of parts posted previously (a while back) by GTPRO. It seems you could easily turbocharge the N/A with the parts you listed, and if you could find a donor car none of them would be difficult to get. My concern would be the amount of boost you could run on street gas. The N/A has a 10:1 compression ratio, as opposed to the 8:1 compression in the TTs (thats for DOHC, I dont know the SOHC compression ratio offhand), I heard of someone running 10psi boost on 10:1 pistons, but that seems kind of high to me. If you could only run a few pounds of boost it would probably not be worth the money, on the other hand, If you really can run 10 pounds of boost it is quite worthwhile, The car is about 500 pounds lighter than a tt, and you would have much better low end power and drivability using 10:1 comp pistons.

 

I'm definitely no expert in this field, but as far as I know the reason that the compression ratio is 8:1 on the VR4 as opposed to 10:1 on the N/A is to allow for turbocharging without running the risk of detonation. I believe the pistons are different on the VR4 from the N/A which gives it the lower compression ratio.
If I read correctly, then DamienX's car is a SOHC engine and therefore it is a completely different engine from the VR4's and the N/A DOHC's. So, turbocharging the SOHC engine would be a whole other ballgame which I'm not sure anyone has done yet (definitely not as simple as just strapping on the turbochargers and being ready to go). There are quite a few differences between the DOHC N/A and the VR4, and even more differences between the SOHC N/A and the VR4, so it would be a massive undertaking which I'm not sure is worth it in the end.....like I stated earlier, probably just better off buying a VR4 altogether. You can get a decent one (~'93/'94/'95) for under $10,000 if you look around.

 

after reviewing corky bell's book on turbo chargers, the only thing I can see that needs to be added to that parts list are one-way check valves to keep from pressurizing the brake booster line. The price would be between $1000-$2000 depending on the source of parts. remember, there are turbos and superchargers out there on base and sl model cars both DOHC and SOHC. DONT go with NOS.....I've had it for 3 years and it has been a big disappointment. Refill the tank all the time plus you have to drive with the tank in the car.....in a wreck thats not the best place for a pressurized tank. It can also seriously wreck an engine if not carefully used.....even one slip up and your pistons could be toast.

 

Compression on the SOHC is about the same as it is on the DOHC turbo.. it's only the DOHC non-turbo that has the high compression.. I think turbos are 8:1, SOHC are 9:1, and non-turbos are 10:1.. or something along those lines..

Keep in mind that JB's turbo SL pushes out about 400hp @ the wheels, running 11psi with race gas on STOCK compression..

 

Yes, the resason for the VR-4 having lower compression is to prevent detonation, so using 10:1 compression pistons you would not be able to run as high of boost on the same octane fuel as you could using 8:1, you certainly could run some boost but I'm not sure how much, also I think the sohc's have lower compression?, so you could run more boost. I have heard of sohc's being turbocharged, it has been done. Also I believe the sohc is still the same block as the DOHC. The whole process looks pretty simple, you might be better off just dropping a TT engine though if you can find one, A sohc engine would still limit the power, you couldnt run as much boost as you could with 8:1 pistons, and the sohc engine is much weaker than the DOHC with or without turbos.

 

Brian at Gtpro, Matt at Dynamic racing, and Geoff from knights turbos all said that you could run up to 7 pounds of boost on stock NA 10:1 compression without much trouble. It just so happens that without the ecu controlled solenoid, the vr4 will run at 7psi. This is also done with no timing retard. Matt said that after 7 psi is when they started having trouble with detonation.

 

7 pounds... interesting thats at least enough to be a worthwhile improvement in horsepower, even at only 7 pounds you would easily have a better power to weight ratio than a vr-4.

400HP on 11lbs???? thats an incredible output, obviously the higher compression would increase the output given the same boost, but thats gotta be close to 500BHP on less boost than a stock 2nd gen. not to say thats impossible, but thats an unusually high output.

If 7pounds is the most you can run heres a couple other things you would need, or at least they would be a good idea
- manual boost controller
- accurate boost guage

 

I was talking to Eric Scarlett about a twin-turbo kit for a base model, and he said you would spin all the way through 2nd with that, and have shitty handling because of torque steer. What are you guy's opinions on this? Supra's are just RWD and have TT engines....why am I geting bad responses on dropping a TT setup in a base? Lemme know!

 

Wait...

if you get NOS how many times a month do you have to refill the bottle??? or how many shots can you take before it runs out???

Also how much is it to refill the bottle???

I just want to know for future reference.

 

Wait...

if you get NOS how many times a month do you have to refill the bottle??? or how many shots can you take before it runs out???

Also how much is it to refill the bottle???

I just want to know for future reference.

Assuming a 50hp shot from a 10lb bottle, you have about 3 minutes of nitrous. Lets say you use it for 15sec a race, that comes to 12 "races" before a refill. Which, will run you right around $40

.jon

 

OOO i see, thanx man.

 

GT wrote
7 pounds... interesting thats at least enough to be a worthwhile improvement in horsepower, even at only 7 pounds you would easily have a better power to weight ratio than a vr-4.
400HP on 11lbs???? thats an incredible output, obviously the higher compression would increase the output given the same boost, but thats gotta be close to 500BHP on less boost than a stock 2nd gen. not to say thats impossible, but thats an unusually high output.

How did you arrive at these horsepower figures? Just curious...

esc wrote
I was talking to Eric Scarlett about a twin-turbo kit for a base model, and he said you would spin all the way through 2nd with that, and have shitty handling because of torque steer. What are you guy's opinions on this? Supra's are just RWD and have TT engines....why am I geting bad responses on dropping a TT setup in a base? Lemme know!

Supras as well as RX7s & 300ZXs are all RWD. The base & SL 3000GTs are, unfortunately, FWD...that's why you will get torque steer if you apply too much power. Not too sure if you'd necessarily spin all the way through 2nd though....afterall, you have the weight of the engine to help plant the power to the ground.

4u2nv
if you get NOS how many times a month do you have to refill the bottle??? or how many shots can you take before it runs out???
Also how much is it to refill the bottle???
I just want to know for future reference.

Good questions....I'd also like to know more about that stuff if anyone can help us out.

 

Dude, the torque on 300hp fwd cadillacs seems to be managable, especially for the senior citizens driving them. And how about all those fwd civics and integras with NOS, superchargers, and turbos; seems like a managable problem for them. SuperC seems to be able to drive his fwd supercharged base 3000GT without a problem, and I sure dont have a problem driving my base fwd 3000gt with NOS......and I dont have an lsd installed either. I just wish the tuner shops would formulate a detailed list of instructions and parts needed for the tt upgrade with different stages of power. Hell, they could sell the instructions for $20 a set and make a little profit for themselves or maybe create a kit with everything you need besides stock vr4 parts.

 

nitroucf wrote
Dude, the torque on 300hp fwd cadillacs seems to be managable, especially for the senior citizens driving them. And how about all those fwd civics and integras with NOS, superchargers, and turbos; seems like a managable problem for them. SuperC seems to be able to drive his fwd supercharged base 3000GT without a problem, and I sure dont have a problem driving my base fwd 3000gt with NOS......and I dont have an lsd installed either. I just wish the tuner shops would formulate a detailed list of instructions and parts needed for the tt upgrade with different stages of power. Hell, they could sell the instructions for $20 a set and make a little profit for themselves or maybe create a kit with everything you need besides stock vr4 parts.

For the most part I agree with you, but who says those other fwd cars with NOS, superchargers, and turbochargers don't experience torque steer? I'm sure alot of them do. How they go about managing it, you'd have to ask one of them. Even with bpu's, the base and SL models will exhibit torque steer to some degree (I'm speaking from personal experience). I'm not saying that the torque steer is unmanagable or that it will totally reduce your handling capabilities, but it is a factor worth considering when adding a significant amount of horsepower.

 

Guys - of course torque steer is a pain. But you all seem to just dismiss fwd as impossible to drive. There are plenty of 10sec civic's with fwd. All you need is a $1k limited slip diff and some slicks. its not nearly a big of a deal as everyone makes it out to be.

.jon

 

ZC3000: those HP figures were from silver bullits post, (400HP@the wheels@11psi)

 

This one guy i've seen around has a civic 4-door with a turbo kit and hub cabs. He said he usually boost anywhere from 7-12 psi...If a civic can boost that high, how come if we put a supercharger or turbos in our cars we can't boost over 7psi? Shouldn't our engine be able to take boost than the pos civics? or is he just B-sing...i'm just learning about turbo cars so i don't know much...

 

If you can't handle the torque steer, let someone else drive. I had one _bad_ incident with torque steer .. the day I got the car I tried launched it.. I almost ran down the side of another car after scooting over about 6 ft in the road (was a parked car on a side road). After that, I learned the neatest trick... hold on to the steering wheel! Make sure your tires are straight when your launch.. and make sure they're straight when you shift, and you will be able to manage your torque steer. Once you're pushing 300+hp, you should get a LSD for common sense reasons (like traction), which will help with the increased torque steer.

 

NA to TT changes

Regarding the TT conversion , it has been done before. It is costly and time consuming but was and can be done . Forget race prepping the engine, and the turbo kit, fuel system and management systems, but if you want the complete VR-4 conversion which was done by a few members (i forgot their names) you have to swap out the tranny for the AWD Getrag 6-speed tran , and install the AWD system with the VR-4 brake system. I only recommend this if you have the money and really really enjoy working on cars and have the time for such a project in which case I'd say "Go for it." Other wise I'd say just buy the VR-4 and work from there.

Then again , if you want to TT your originally NA 3K , there is a chip made by a certain company (FUCK ME I can't remember who) which you can program to regulate your launch RPMs (so even if you floor it off the line you won't spin the front tires) That is obviously dependent on your settings.

As far as the quarter mile is concerned , You're driving your car in a straight line. So I wouldn't be too worried. As long as you are capable of keeping your steering wheel steady you'll be ok. NOW if your FWD has something like 500 hp + , then YES there is more potential for torque steer, hence keeping your wheels straight becomes a little more vital at this point. It most likely will be a bit harder to keep the car straight with that much power but, with practice one should be able to adapt. Again, as long as they're straight your fine.

Here's my philosophy:

Whether your car is RWD , FWD, or AWD when you add more power to a car, there will always be increased potential for loss of control and very likely a more catastrophic accident. That's what PRACTICE is for. Racing is not for the faint hearted. Don't push your car beyond what you can control. If you are not capable of controlling a car with that much power, you shouldn't be driving such a car. OR what I recommend: With each mod you install you should be practicing and getting a better feel for how your car accelerates and handles (Us daily drivers shouldn't have too much of a problem with this) . . . Adaptation is Key. There are plenty of people running quarters on High hp FWD, RWD and AWD cars so it's not impossible. It may take a little practice or It may take a lot of practice but it is doable.

Hope my .02 of wisdom didn't bore you. I know i got bored after reading it a secong time before posting it HEHE

 

Hey dont feel bad about the tt conversion. I hear this s*** all the time. about how its not worth it or theres no point just go buy a vr4. I have a diamante SOHC and I am building my twin turbo setup as we speak. There is definitly gonna be some torque steer, depends on how good the suspension is(meaning what kind of shape its in). As for transmission I dont think mine could handle the turbos so I bought a custom made level 10 transmission, for about 3500 with upgraded torque converter. All I have to say is good look in building it. It is gonna cost some money but if thats what you want to do than do it. Dont listen to other people.