been shopping aroun for a BOV for my S70 and wanted to get opinions on affordable and efficient. Thanks gang!

 

BOV are stupid, Volvo already has a recirculation valve in. Unless you are running a full FMIC and have a tune that accepts a BOV then I would stick to recirc valve.

And if you are adamant on getting one you'll need a hybrid meaning big bucks.

Also if you are automatic and doing this without a tune, you might be losing power.

 

A BOV is completely unnecessary on these cars... and will actually cause problems. Here's why: The air that's already within the intake plumbing has already been measured by the MAF. This means that the car expects that air to eventually make it to the engine, so it's already computed the amount of fuel needed for it. When you let the throttle snap shut, the recirculation valve just sends it back through the intake side of the turbo, keeping it within the intake plumbing and letting it recirculate as the engine needs more air. The ECM will inject fuel in a quantity it expects to based on what has passed through the MAF and throttle opening. If you let that air escape to the atmosphere, the result will be an overly- rich mixture for a few seconds every time the BOV operates. This in and of itself isn't a problem... but the ECM will then try to correct this rich mixture by leaning it out some. By that time, it's done "looking" for the recirculated air and again relying on the MAF signal, so with the correction, you'll run lean for a few seconds, until the computer corrects it again. Lean operation is not good for the engine, and if you happen to get on it while it's still tending towards the lean side, you can do some actual damage, though it's not all that likely. Some people call BOVs "show- off valves." This is a fitting name for them on these cars, and you're doing harm by installing one. If you HAVE to have that sound, get a hybrid valve that releases a small amount of that air to produce the noise, and allowing the rest to recirculate to reduce the A/F inaccuracy.

 

Well said Carrots. The nice thing about the recirculating valve is it also helps spool the turbo between shifts...

 

sounds good bro! I'll leave it as is....
I got another question....I have a ECU from a T5 and wanted to know if I could put that on my GLT? If possible will it make any difference? Learning as I go guys....gotta get use to these European cars. 10-8!

 

Didn't know GLT S70 where actually turbo since GLT 850's were not. My mind tells me that mixing ECU's is a very bad thing, especially since i think the T5 and GLT are completely different engine (Isn't a GLT a 2.4? and the T5 was a 2.3?), but i am no expert on this.

 

You CAN put the T-5 ECU on a GLT... it's done sometimes as a sort of "ghetto tune," as it will allow the turbo to boost to T-5 levels. However, it's really not optimal. It'll work, but if you run it hard all the time, you'll eventually pop something. The difference between the 2.3L in the T-5 and the 2.4L in the GLT is that the 2.3 has a lower compression ratio and slightly thicker cylinder walls to allow it to withstand the higher boost. That being said, a 2.4 can handle more than factory... but because of the compression difference, a proper tune is the better way to do it If you do, you need to go with an ECU from a 97 or 98 if your car is a 98. 99 and 00, the ECU has to be matched to the car, and good luck finding a Volvo dealer willing to do that with the wrong ECU for the car.

And for information: S70 GLTs are all low- pressure turbo. The 1997 850 GLT was, also. First year for the 2.4 LPT engine.

 

Thanks again guys! Probably not worth putting on the dyno then? Maybe I'll just go with looks on this one for now and keep an eye out for a 94-96 850 and tune that.

 

I never said you can't tune a GLT. Just that sticking a T-5 ECU in isn't the best idea due to differences in the engine. The 2.4 isn't especially weak... it can't take what a T-5 can in terms of crazy power, but 250-275 HP isn't out of the question. The big sticking point with an LPT is the compression ratio- it's too high for really big boost unless you run racing fuel or other higher- than- normal octane fuel.

 

would it be worth putting on a dyno? I have a friend who can dyno it for me but would I need additional high performance parts or just tune the ECU? Still new to the Euro cars and trying to get a feel for them. Plus here in Hawaii it doesnt seem to have a big following of volvos, mostly japanese imports, actually mostly ALL are into tuning Imports. I was thinking upgrading ECU, cat back exhaust ( still trying to figure out which brand) and suspension. Thanks Carrots....you've been a great welath of knowledge and help.

 

Look at the "Volvoforums resource thread at the top of most forums for information on where to get parts. Search the forums for info on what people consider to be good quality. Also, look into the Volvo 850 thread- there are several people over there that have modded cars and will help you- remember, a '98 S70 is basically a facelifted 850 so performance parts for an 850 will usually fit an S70. Keep in mind that there are more high- pressure turbos in "850- land," and there's more stuff out there for those engines, so things that work on an HPT car may be too much for a stock LPT block to handle. Again, the primary reason for this is the higher compression ratio of the LPT engines. Premium fuel is best for any turbocharged Volvo, though they can adjust for lower octane at the expense of performance and economy, however, if you do much in the way of mods, I'd run premium exclusively. As with any performance mods, you get what you pay for, although price isn't the best indicator of quality or- more important- how well- designed and engineered a product is. IPD is known as the best- their stuff tends to be expensive, but it's backed by research and a company that cares about quality and service. They also come out with new innovations all the time.

 

There is not really a big following for Volvo's anywhere. and catback, do it custom, much cheaper, or EST is pretty good, suspension would be last and most expensive. Most likely a Upsolute tune is best idea.

 

like I said...you guys are a wealth of knowledge. gotta take my mind set out of "japanese tuner" mode and start learning the euro way. I noticed IPD has a upgrade for the ECU, bout 700 bucks. is it really worth it? Just for there exhaust and ECU upgrade shipped to Hawaii is gonna be about 1800....if it makes that big of a difference then I have no problem with the cost if its worth it. thanks again guys!

 

IPD's tune is one of the best. Some of the other, cheaper ones give you the power, but they make the car run rich all the time. Same with the exhaust- theirs is top quality, but it's pricey. Look at the OBX systems if you want to save a bit of money- they're a lot less expensive, and considered to be decent, if not the best quality.

 

thanks....yeah obx seems reasonable and RICA has a ECU upgrade thats 500.00 and seems to boost the same as the IPD ECU which is 200 more. Im figuring if I can get about 220 to 240 horsepower I'd be happy with that. Im going for the "sleeper" mode cause all of my friends think Im out of my mind buying a volvo but I've been convinced after doing my research

 

I would go with custom, i can get a 2.5" made and installed for about 250 bucks and watch it be made. But OBX is really fairly priced.

 

1. What year is your s70?

2. What kind of performance are you looking for out of your s70?

3. What is your budget?

Volvo's are a niche market for aftermarket parts. Do they exist yes. Are they cheap like Honda, etc... No. Spend your buck wisely and you will get quality parts not quantity.

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1. A BOV can be put on your s70 be it manual or automatic. However if your an automatic it will only go off when you let off the gas. Cool for awhile, it gets old after some time. Also you have a CBV already on your turbo which acts as the BOV as has been stated in the previous posts. You can run this and a BOV but you don't have to. You can get a CBV blocking plate and remove the CBV put the plate on there and run the line that was run to the CBV to the BOV. You may run RICH if you run a BOV. I know I sure did. Plus you can leak vacuum and boost which is a problem as well.

In the long scheme of things unless your going completely custom a BOV isn't worth the money.

2. You can run a T5 ECU however I would just get an ECU upgrade and be done with it. It will be better in the long run. Might cost more but it is well worth it. IPD USA, RICA all worth the money. You get a better tune with these companies compared to companies like SpeedTuningUSA, Inmotion and Upsolute.

3. If your looking to do a downpipe upgrade and catback system upgrade do these before the ECU is tuned. As the ECU can be tuned to take these into account. 3" mandrel bent downpipe to a 3" mandrel bent catback system with a Hi-Flow CAT and Free Flowing Straight Throught Desgin muffler (Maganflow, BORLA).

4. Before you do any of the above you should have your car checked and make sure it is running like a top. Then get a boost gauge installed one that can read 25 In Hg / 25 PSI. And then get a base dyno run. So you know what your working with. Then mod from here. I suggest silicone vacuum lines and turbo hoses as well. SAMCO and Stylin Motors Inc. make them both. Well worth the cost and get T-Bolt clamps for the turbo hoses as well.

 

It's a 98 GLT. I think I'm gonna go with the RICA but will take your advice on getting the exhaust system first. I wanna use this as my project/learning car and possibly get a 96 850 that someone is selling here for 1400.00 with only 100,000 miles and body in mint condition.

 

Could do an open source dyno tune. Fairly in-expensive from most shops, atleast around here.