What turbo should I run on my combo? An age old question I hear multiple times a day. Quite frankly, I love it! Boost and turbos just make me happy. In the last couple years I have seen such a trend of people who ran no power adders (adamantly or not) come over, people who had blowers and nitrous come over, and those who have ran turbochargers for years step up their game significantly!
But I digress... I thought I would shed some light on my OWN evolution and discovery of good combos that I have learned from my personal race cars as well as a myriad of customers whom I work closely with.
One thing that sets Motion Raceworks apart from other businesses in the industry is our desire to do right by the customer. This means I try to build not only what they need at the present time but give them an easy adaptability in the natural progression as they go faster, build combos with more hp, etc. I have NO INTEREST in selling customers parts twice when I could sell them the right stuff once. I was misled by a number of people and companies in the beginning of my days building boosted and EFI cars. Fortunately enough I have enough rebel in me to be able to turn around and say "I'm gonna try something different this time around". But enough about me.
The common denominator I see in new builds these days are this (whether it be a Ford modular or a late GM LS or LT). "I would like to make 1000rwhp reliably" and I'm looking at this turbo my buddy runs who did it. I will listen to them tell me how cool their buddies car is and then ask them this "Do you see yourself being content with that for more than one season? Do you wanna beat your buddy". The answer is ALWAYS a resounding "well no I won't be content, I wanna go faster next year or the year after but just wanna get the car going this year".
For a typical 3-400 cubic inch combo, a popular combo these days seems to be a single S400 Borg Warner series turbo or some variant of it. Many customers will even start off the combo with "how much is your S4xx". My question to you and all of those customers is why limit yourself? It has become traditional thinking to go to one of these basic midframe setups because it is horsepower to get your current goal and relatively affordable. However, the problem lies with THE NEXT STEP. Most of these guys will go their mid to low 8s on these combos and become ADDICTED! Lets face it, you rip off some solid passes and you are hungry for more, maybe you even got an ass whooping by some guy at the track. I personally have BEEN THERE myself, its actually a frustrating point to be in. You possibly have a car that is only 3 or 6 months old you built around this turbo fitting and now you have to redo a bunch of it and who wants to do it? You are kind of land locked into buying whatever new pretty cover is out there with the hopes it makes 50 more hp, or some new wheel that is version 3.8405 with a bullet tip and some abbreviation that you don't understand. Anyways, what is your next step?! You don't have one do you?
My goal is to do things right the first time. So my against the grain thought process is why not do a pair of small singles, namely the t4 variant? This gives you a GREAT selection of exhaust and compressor wheels anywhere from start to very WILD. Now I know what you're thinking... Doug, that sounds expensive, especially because I likely said run one of the Precision turbos, because their compressor wheels just can't be beat in that series as well as most.
Here is the breakdown. That "budget midframe" that you think is budget is in fact no longer budget. What was originally derived from a tractor or diesel turbo now has more bells and whistles than a damn luxury car. For numbers sake, these turbos are close to 2000$ fully optioned out, some are now into the 22-2300 clams to get the one your buddy has. An optioned out 85 or 88mm turbo can push 13-1400 at the motor maybe a few more. That being said, a pair of Precision billet 62 wheel turbos can make 13-1400 also, with a price tag of just over $2100. So what is the advantage? The advantage lies in the NEXT STEP.
Now before I get on my soap box, I have ran MANY of my own combos. I am by NO MEANS calling anyones baby ugly or acting like any combos are inferior. There are plain and simple some just amazing setups out there these days (many that run the S400 series or other midframes), they work great, and they win races. But I have a good idea where things are maxed and what stuff is capable of, and this is what I am speaking to. If you are a guy starting from square one, why not have a plan in place to hedge that time in your build?
You have now maxed out your midframe turbo. What is your next step? Buy an inbetweenish Dual ball bearing $3300-3700 unit and make 16-1700 hp. That is all good and fine but this unit is now larger, it has now required you to possibly redo your downpipe, coldside, and if you are unlucky it doesn't fit in the same exact location because who builds stuff with tons of extra real estate? Hard enough to fit stuff in a street car as it is. Second scenario. You had Precision 62s, now its time to step up. You call Motion, order a pair (we usually have in stock), you bolt on a pair of 7675 CEA Billet wheel turbos. They literally bolt in the exact same location, zero modification. The pair of them cost $3200 and you are rolling. Literally 30 minute upgrade, you now have a combo that can make 2000+hp.
So your thoughts are, but with twins I have to run two wategates. Well to be honest, you should consider running two wastegates whether a mid or large single or twins. Truth be told it makes the piping and plumbing much easier, it makes your wastegate efficiency way higher, no weird merge to crack or break or not flow as expected, and two 40mm or 46mm wastegates cost not much more than a large single turbo, simply put you should have twin wastegates on either combo.
So my point is this. Whether or not you are a fab guy, you are going to save yourself a TON of time and heartache by starting with a twin setup from day one. The cost is the same or less with twins, you leave yourself HUGE growth potential with zero refab. One thing I haven't noted yet is that these twin turbos are quite small and easy to package overall, from my experience they fit in places easier and require less fabrication. In my opinion twin turbo setups are more powerful, have better responsiveness (save me your "my single works just fine" talk). In addition to refab, most combo revisions require cutting, painting, new plumbing etc. The costs go deeper than the surface we spoke about, but are harder to quantify. End of the day, who wouldn't rather be in the garage drinking beer and detailing the race car rather than cutting and chopping a combo that already should be done.
This is all food for thought. I hope with this blog I catch a few of the guys early on and give them the ability to grow and drink beer while they watch their friends refab 12 different turbo systems trying to keep up.
Go Fast. Be safe!