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Modding your 2.3L FWD Turbo Volvo 850, 70-series


Volvospeed Spy
Jun 8, 2003
St. Pete FL
This is the latest rendition of my intro to tuning these cars that I first wrote some years ago on VS and cross-posted over here. Since then a few things have been taken out and added, and changed.

Since it seems multiple times every day, we have people asking the same questions again and again ("What mod should I do first?" "Can my car be fast?" "What's the best bang for the buck?" "Why is the sky blue?" "Has anyone modified 850 turbos?" etc), I am going to attempt to lay things out clearly for some of the noobs. This will focus on 850 turbos primarily, as that is where the majority of my experience is. There will be notes and information about other cars though as well...

It is my hope that this post in conjunction with the pinned FAQ thread will be able to guide people to the answers to some of the more repetitive questions relatively easily.

I'll break it down as follows:

I. Engine
A. Limitations of the stock turbo
B. Upgrading the turbo and a new set of limitations

II. Transmission
A. Limitations of the stock auto transmission, and options for improving it
B. The better M56H manual, and possibilities it opens up

III. Miscellaneous Considerations

I. Engine

Overview: The engines in these cars (850 turbos, T5's, T5-R's, and R's, as well as all 70-series T5's [may mention early V70R's], all of which will be referred to as the HPT turbo cars as they are mechanically very similar) are 2.3 liter 20 valve DOHC designs, with a stock turbocharger and settings as follows:

All HPT 850's received TD04HL-15G turbos, with stock boost for turbo and T5 models set at 9.6 psi, and T5-R and R models at 10.5 psi (stock hp are 222 and 240, respectively). (The European 850R received a 16T turbo)

All HPT 70-series cars received 16T turbos (with the exception of the V70R's, which received 18T's in 98 and 99, and 19T's in 2000). Not sure on stock boost setting, I'd assume it's around 10 for the T5's and probably 12.5 or so for the R's.

Stock airbox design is excellent, pulling cold air from behind the grille, and can be easily modified to be even better. Stock exhaust has nice bends, but relatively small (~2.25") piping and very restrictive cat and muffler.

That's the starting point info. The overview of the engines.

With these cars, there are basically two relatively easily attained levels of tuning. The first is that in which the stock 15G turbo is the major limiting factor in increasing performance, with a ceiling around ~270-300bhp. The other level is one in which the turbo is upgraded, and performance is limited mainly by the transmission and later, the connecting rods.

A. The HPT cars with their stock 15G turbo reach their limitations fairly quickly. A reprogrammed ECU, coupled with good 2.5"-3" full exhaust, will generally get you to the limits of the 15G's efficiency. The ECU will increase fuel and boost maps to about 15-16 psi maximum boost. For a little more performance, you can add a boost controller (don't think you can on the ME7 1999+ cars) to decrease spool-up time and increase the boost an extra pound or two (beyond that isn't too useful).

Essentially though, at this point, if your car was in good tune to begin with, you will be in the area of as high as you'll get with this car, barring band-aid add-ons like nitrous and water/alcohol injection. You should be running mid-low 14s with anywhere from 270-300 horsepower at the crank. Extracting more power with the stock turbo is becoming difficult, because at higher RPMs, the turbine side limits exhaust flow. (though if you insist, you can gain some power by water/alcohol injection and/or nitrous oxide)

B. If you choose to upgrade the turbo (upgraded compressor wheel for the 15G, or using 16T, 18T, or 19T turbos are easiest), then you will potentially be able to yield significant gains in power beyond 17-18 psi. The 15G isn't too efficient even at 16 psi, so even at the same boost levels, you will feel a gain because the air won't be so superheated. However, you won't be able to increase the boost as high on this turbo as with the 15G, because it's actually flowing enough air at those higher boost levels that you'll be needing more fuel in order to make more power (*Bill at Adrenaline Racing recommends upgrading ECU map at any level above 16 psi when using a 19T).
This is the seperating factor for this level, because fuel mods apart from the pre-made performance chips are a consideration. Larger injectors and a rising-rate fuel pressure regulator are options, as well as the possibility of a custom ECU program. Best case scenario would be a custom ECU program used in conjuction with larger injectors.
*Since the time of writing this, it is easier to obtain ECU tuning for higher levels of modification from companies like RICA and IPD/TME, among others. That would be the route I would recommend. Civinco has also proven to be a viable option, depending on the user.

The difference in turbine housings:
There are 3 turbine housing designs (with two variations having been seen internally in the angle-outlet housing, but we will ignore that for now!). Conical outlet flange (94-95 850 turbo, 95 850 T5-R), straight outlet flange (96-97 850 R, T5 and GLT, 98 model S70 R, T5, And GLT), and angled outlet flange (All cars 99+ excluding the newer cars with KKK turbos). User jonsayre has contributed a photograph of all three side-by-side. http://volvospeed.com/vs_forum/index.php?showtopic=92545

As you can see, the difference is in outlet size. This has an effect on performance, and all three housings are interchangeable and can be placed on any TD04HL turbo (13G, 13T, 15G, 16T, 18T, 19T, sorry if I forgot anyone!) by removing the center band clamp. Outlet sizes are <2.5" for the conical, >2.5" for the straight, and ~3" for the angled outlet. They also come with varying wastegate actuators, with the angle-outlet turbos receiving the 300/70 actuator with the strongest spring (straight outlet 16T was 215/60, conical 15G was 150/30, others may vary).

Beyond the TD04HL Volvo turbos, there are a few more options. The first is the Hahn Racecraft TD05H series of turbos, which are Mitsubishi TD05H turbochargers with a Hahn Racecraft turbine housing which gives it the standard T3 inlet flange. This is the same flange Volvo uses, but they use a raised lip on the exhaust manifold and recess in the turbine housing to make a mechanical gasket-less seal. This lip on the manifold must be machined down by a mill in order to use one of these turbos. There are 16G, Big 16G, and 20G compressors available in this series of turbo, and there are a handful of members using these turbos with great success.

In addition to the Hahn 16G/20G turbos, it is possible to use most Garrett T3-flanged turbos. This opens you up to a whole new world of sizing possibilities. It seems that the older T04B and T04E compressors (which are used in T3/T04B and T3/T04E hybrids) are being replaced by more modern GT-series ball-bearing turbos, although the 50 trim T04E is still an outstanding compressor and very versatile for power levels from 300 whp to 400 whp. The GT-series of turbos from Garrett provide a number of options, I would start with the GT2871R as a great turbo to use with the stock transmission and bottom end. This turbo will comfortably make 270-320 whp on our engines I would say. The next step is a GT3071R, and the GT3076R... These are great options for mildly built bottom ends using manual transmissions or upgraded automatic transmissions. The GT35R is an excellent turbo, but unless you are aiming for over 450 whp I would not say it is necessary. It is also possible to use some Holset turbos. When using big turbos like these, you may run into firewall clearance or rear transmission mount clearance issues. Don't be surprised...

The engine's internals are reportedly good to around 400 horsepower with proper air/fuel tuning. However, many premature failures of connecting rods have happened due to high boost levels at low RPMs, or poor tuning in general. With boost coming on gradually however, 320-340 wheel horsepower or possibly slightly more should be attainable if done carefully. The problem is how well the ECU can respond to and correct detonation events. At higher, less stable boost levels with stock boost control and oddly proportioned turbos (like the 19T), it is difficult for Motronic's algorithms to effectively combat these problems before permanent engine damage has occurred. There is also a much much thinner margin for error and bad gas and such at the highest power levels.

There are now affordable H-beam rods available from either Sten Parner (bad because of exchange rate now), or R-Sport International, among a few other companies. These rods will allow you to do a mild rebuild of the engine and take out the weakest link in the bottom end. This will allow you to make 350-400+ whp safely and reliably with proper tuning.

The stock intercooler setup is very good, utilizing all black-painted aluminum piping, and an OK bottom-to-top intercooler. In my experience, the abundant rubber elbows used in this system have proven very weak under high levels of boost, and are costly to replace.... I would recommend getting a kit of replacement elbows in silicon. Drop-in upgraded intercoolers are available, though I don't know at what point they become a serious consideration. (there are also "reverse-flow intercooler setups available that reduce the distance of the intercooler pipes to improve throttle response, but it's my belief that the benefit of added cooling of the longer plumbing helps cooling enough to make the reverse intercooler piping (~$250) not quite worthwhile.) There is more discussion and more rambling on my part in the FAQ thread regarding intercooler upgrades.

Stock ignition and fuel systems are very good as well, basic plug, wire, coil upgrades will probably yield some small gains, especially at higher output, and the fuel system is easy to upgrade. The first upgrade to consider in the fuel system would be the injectors, which stock are 315cc/min as I recall. A general rule of thumb on our engines with stock fuel pressure is that for each cc/min of injector size, you can achieve about 1 bhp. So with 315cc/min injectors you can achieve about 315 bhp, or 260-280 whp. There are Bosch-made Volvo injectors which are a direct replacement for the 850's stock orange top injectors. The 70-series T5 cars in 1998 received white injectors which flow roughly 350cc/min. In 1999, all 70 series T5 cars received blue 395cc injectors, which were original equipment on those models for quite a few years. In 2000, the V70R AWD received green 468cc/min injectors, which resurfaced again in 2004 when the R AWD V70 and S60 were introduced. A quick and easy way to up effective injector flow is to put in a Dodge 4-bar fuel pressure regulator from a 2.2 liter turbo Dodge (from the late 80s, early 90s). Which gives an increase in flow over our 3 bar.

Apart from these injectors, any high impedance Bosch injector can be used in the stock rail, but accompanying tuning ought to be done to ensure the car will run efficiently with these injectors. It is possible to run larger injectors with no tuning provisions for them, but it will be far from an ideal setup and mileage will suffer.

In addition to upgrading the injectors, the stock fuel pump will eventually run out of steam. I am not totally sure of where this occurs, but believe it is somewhere shy of 400 bhp. There is a very easy and inexpensive upgrade available though, the standard Walbro 255 lph in-tank pump. (The part number is GSS 342 and an installation guide can be found in the FAQ thread)

II. Transmission

The stock automatic transmission doesn't seem to like seeing power above 300bhp. However, some people have been running higher amounts just by doing simple things. There are two very easy and very significant things to do that will help the life of your transmission great amounts. One is flushing your fluid (also upgrading to better fluid helps), and the other is the installation of a transmission fluid cooler. With these two simple things, these transmissions (in good shape) have held well over 300 horsepower, though they are still far weaker than their manual counterparts. You will find by checking your transmission fluid regularly after modifying your car greatly, the condition of the fluid deteriorates pretty rapidly. Flush the fluid again as soon as its condition has deteriorated.

B. There are to my knowledge two manual gearboxes for the FWD cars, the M56 (available in H and L versions) and the M59. Some people have gotten the M66 from the S60R to work in these cars, but I will focus on the 850's offerings. The M56 has an open differential, but is supposedly stronger than the M59. The M59 however, was used in Europe in the R's, and came with a high power-handling clutch and a limited slip differential. The M56H and L differ only by gear ratios, both being very strong transmissions. When using the Volvo manual transmissions, the R clutch kit should be capable of handling most builds regardless of driving style, until you start approaching the 350-400 whp level. In my car with 19T turbo, stock injectors and intercooler, and Upsolute tuning, I ran 13.31 at 107.4 mph, this with the M56H transmission and R clutch.


There are other things to consider when tuning these cars. One is that they can run fairly well with very worn components, and in some cases do well even with fairly damaged components. For this reason, many of these cars out there today are in very poor shape mechanically, though it is not readily apparent (most people don't notice something is wrong with them, and if they do, if it's not affecting the car's performance they will generally overlook it). Often times, people will do certain modifications and not yield the gains they are expecting. This is most often due to these small problems that had been overlooked by previous owners and such.
Stage 0 is unbelievably important in these cars. Before modding, replace the distributor cap and rotor, spark plugs wires, spark plugs, fuel filter, all vacuum lines, test compression, look for oil leaks, and generally make sure the car is up to spec. Buy gauges. Generic boost and A/F ratio gauges are fairly cheap and very useful in tuning these cars. This is also a good chance to do minor upgrades like better air filter, exhaust, and minor ignition components. Once you're confident your car is running as it should, go ahead with the major modifications, you will save yourself a lot of headaches and troubleshooting (not that there won't be any involved!). Most people don't acknowledge the increased wear/load placed on basic components when you increase engine output by ~50%. Refer to the FAQ thread for more on Stage 0.

Another important consideration to make before sinking lots of money into one of these cars is that it will never be a drag racer. With fat (for these cars, 225 is considered pretty fat) street tires on 16-17" rims, traction will be a huge problem, even around the 300 horsepower level.
Larger tire sizes would require smaller offsets or spacers, accompanied probably by fender-rolling. The wheel wells in these cars are very snug. Drag radials are but a small help, and slicks are far from reasonable for a daily-driven car.
Overtaking cars on highways, and racing from a roll will be on par with mildly modded f-body V8's, and other extremely fast cars, but you'll find that from a stop, you will be at a severe handicap..

The setup I would recommend to most users: TD04HL-18T turbocharger, IPD intercooler upgrade, SAMCO silicon boost hoses, 3" exhaust system, 350cc or larger injectors with custom ECU programming from a reputable tuner, and either manual transmission swap or automatic with aftermarket cooler and nice fresh fluid. This will produce an extremely quick car in the 18-21 psi range, and will be relatively reliable as it utilizes all Volvo factory parts and design considerations while not exceeding the safe limitations for the stock block.

Some vendors for the chips (I'd recommend custom exhaust, and trying to find injectors independently), and turbos, plus other minor performance parts...

- http://www.ipdusa.com</a> - the most reputable Volvo performance parts place in America, they are a distributor for TME, and top-notch, if a little expensive.

- http://www.viva-performance.com - George is a US distributor of RICA ECUs and a number of other parts for these cars.

- http://www.samsteffansson.se/samindex.html - SAM Steffanson, very extensive catalog of parts although located in Sweden.

- http://www.eurosporttuning.com - If you refer Volvospeed, Frank will be very helpful here, and there is also a small discount. They are the US distributor for the Swedish tuning company SAM Steffanson.

- http://www.upsolute.com/ - A more budget-minded chip tuning company.

- http://www.speedtuningusa.com - Another budget-minded company.

- http://www.stenparnermotor.se - A reasonably-priced very reputable engine builder and parts supplier in Sweden. He speaks English well so e-mail is a good way of contacting him if you would like to order parts from him.

- http://www.r-sportinternational.com/ - An up and coming Volvo tuning company, they are able to provide H-beam connecting rods at an affordable price as well as other parts.

- http://www.kaplhenke.com/ - Another up and coming company, specializing mainly in higher end suspension parts.

- http://www.atpturbo.com - These guys are a generic turbo dealership, with a ton of offerings from Garrett and I believe a couple of other manufacturers, as well as vital things like fittings and silicone couplers, mandrel U-bends, etc. This is where to go if you are upgrading beyond the TD04HL series of turbos or are fabricating your own exhaust or front-mount intercooler kit.

- Board member Joseph Essaye (JHEIII874T5M) is a dealer of Samco Hoses and a number of other parts (Limited-slip differentials, Walbro pumps, etc) and is excellent to deal with.

- Board member Mike (thelostartof) is an excellent connection on OEM parts, performance exhausts (When he is making them :) ), and generally very helpful in tracking down parts when it is crunch time.

- Board member 300+ T5R 855 (CJ) could be known for his attention to detail and absolute demand for perfection. He distributes and manufactures various useful and in-demand parts for these Volvos. http://www.yother.com/ is his website.

These should be enough links to get you started, but if you really want to shop around please browse the pinned FAQ thread, as it is chock full of meaningful links and other data which has been omitted here.

If there are any questions unanswered here, feel free to PM me, or search the forums.

Kind of unorganized, may work on that in the future... Feel free to add/comment... I may revise/reorganize at a later date. For now that's enough of my company's time wasted on this thing ;)
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Yes this is very good information, cant wait to get this one up on the site. An idea - what about combining this with andy's (mAyday) 850 info article and sort it around a little so its a "Staged Mods for the 850/70 series cars" ?
tryckj?vel said:
Yes this is very good information, cant wait to get this one up on the site. An idea - what about combining this with andy's (mAyday) 850 info article and sort it around a little so its a "Staged Mods for the 850/70 series cars" ?
Eric - AIM when I get home. I got 2 articles on 850's I've done I need to polish up and finish.

Additional information I have picked up in the year or so since I wrote this:

An outstanding new vendor for FWD Volvo performance is Volvo Motor Sports, VMS. http://www.volvomotorsports.com

Additionally, I have found through very reliable information that the 19T is not nearly as safe to run on the 850s as a 16T or or 18T, reason being that the Motronic 4.3 system cannot regulate it efficiently enough and support it well enough to avoid bending rods in a long term sense. However, there are a number of people running 19T's on their 850s with no complaints thus far. There have also been a number of bent rods with this turbo, so at least you have been warned. The Swedes do not generally like it.

Also, my information regarding what cars the 18T was found in is wrong.

It is found on 1997-1998 V/S70R FWD/AWD cars in Europe with the manual transmissions.

I will also type up a post regarding knock retard in Motronic ECUs (not technical, just an "observations from the field" type thing) later tonight. ;) ;)
Hmmmmm! BSR's PPC, a BMC Carbon Airbox Intake, a 3'' DP+Exhaust are being begged by my V70R once it gets a new tranny [which I guess I will adapt a cooler to now once it is in!]

Thanks for the info
I am going to update this thread with pictures and extensive info on my car, once I have it somewhat finished (mid-low 13 trim) in the next month or so... After I get a few track times in.

Stay tuned :)
Question about the newer cars

Frist off, great post dude.

What about the driveline on the newer AWD models. What can they handle? What improvements can be made? I've noticed that the WRX STI, ya know 300hp blah blah blah, is very quick 12.xx sec 1/4 etc etc. (I don't want this to turn into another WRX debate) I know the S60R is at a disadvantage b/c of the weight, but I don't think that would be a matter of 2 seconds. This would lead me to believe that there is some time left on the table from the AWD. I wouldn't know from experience as I haven't driven an s60r. I have driven an STI. I could understand how the scooby would have the AWD thing down, they've been doing it forever. Are the newer volvo AWDs 4 wheel, or are the front and read diffs open? More info on these would be super and very informative for all of us I think.

Anyone able to shine some light?
Not sure if you'd like to include this in your article composition or not, but upgrading to a better coil, such as MSD, etc is certainly worthwhile.

We purchased two MSD coil upgrade kits from EuroSport tuning, which come with Magnacore 8.5mm coil lead, mounting bracket, MSD coil and instructions.

The first car we installed this in was 1997 V70R AWD Manual.
This car has a TME chip, decent cat-back exhaust system.
- Instantly noticable improvements in throttle response and better 'pull' under load

The second car we installed the kit in was a 1995 850T5 Auto.
Standard ECU. Standard exhaust.
- A big difference also, especially up hills and generally better from lower RPM.

EricF said:
If I see that people start to ask about tuning the LPT cars here, I'll write a little about them, but for now this should answer most of the questions the board gets regarding FWD tuning.

If you could write alittle bit about tuning the LPT cars I would appreciate it quite a bit. Or even just send me a PM. My stage 0 is done, and im ready to start with other things. Im really not sure where to start. Thanks - Kyle
Ajax5678 said:
The canadian 850 R Manuals had more HP did they not? I'm guessing just an ECU thang? 250 or something close to that.

Bigger injectors, 16T turbo, limited slip differential... All I can think of right now :)
Hey, nice job. Tell me more about my car, if you would!! I'm dying to here more stuff about it. Turbo type, trans ID, that kind of stuff. All I can tell you is that I really hooks up and goes pretty well for a little 5 banger. It's quicker than my old Chevelle I had.

'01 V70 T5 (high pressure), has the geartronic trans (LSD?), fly-by-wire.
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