Below are my options for turbo rebuild. Anyone have any suggestions on which way to go? I am looking for a reliable configuration with more HP and as few other mods (especially complicated or pricey ones) required as possible. Please educate me if you have any experience with this. The car is a '94 940 Turbo wagon. The options were quoted to me by the rebuilding shop, and all the upgrades are essentially the same cost.

Thx,
Dave


Upgrade to 15G TD04 (275 HP)

Upgrade to T3 60 Trim (325 HP)

Upgrade to T28 (300 HP)

Stock rebuild

As Brian mentioned; those aren't the HP figures you're going to get from YOUR car. Those are the max HP numbers that particular turbo can produce.

For starters, your car is putting out about 165 HP (assuming it's stock). If the only mod you made was the turbo, you would get no increase at all -- in fact, it would feel slightly slower because you would get a slower spool-up time. A "hopped up" turbo may be capable of making 100 lbs of pressure, but your wastegate is just gonna limit it to the factory setting (unless you modify it).

Your current turbo is capable of making way more boost than your engine is currently getting -- it's just being limited by your wastegate.

The manual boost control and guage that Brian mentioned can get you close to 200 HP for very little money. But make no mistake about it; you are asking the engine to work much harder -- and that comes at a cost.

Jeff Pierce
--
'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

i'm suprised the T-3 can improve h.p. that much.thats what i had on my early GLT's.i do enjoy boost but the 960 I-6 helped me get over it with out the PITA expense and labor of a turbo replacement.
--
83 242 DL -129k, 92-965-195k, 94-965-203k, 83-242 GLT-Gone, but not forgotten,83-245GLT-1'st one (the 1'st 3 currently on the road)

I don't have any first-hand experience with turbo rebuilds/upgrades, but I'll try to give you what I know on the matter.

First - the HP numbers look like the point at which the given turbo would become inefficient, assuming the engine had the supporting modifications (additional fuel, air, and exhaust flow) to make that level of power.

Second - the turbos. I don't really know much about the T28... and you've already experienced the performance of the stock TD04-13C. The 15G is probably a good choice if you're considering a few more basic modifications (slightly increased boost, free-flowing exhaust). It should spool up about as quickly as your stock turbo. If you've really got the bug, the T3 would be the better choice. It would probably be laggier than your stock turbo, or the 15G, but would have more upside once you get past the most basic mods.

Third - whatever you end up doing, you sound like a candidate for a manual boost controller. This device will dramatically quicken turbo spool up, even if you keep the stock maximum boost. Important to also install a calibrated boost gauge so you can see what you're doing.

- Brian '93 945T... mbc @ 9 psi

Dear Cole,

Good p.m. and may this find you well. I've never driven any turbo-charged car. I understand seeking advice on the best deal for a turbo re-build. But seeking modifications that go far beyond the original design seems to me to be asking for trouble.

A Volvo 940 is not a Porsche. Even Volvo's own engineers' efforts to install a more powerful engine - the 6 cylinder - were not an unqualified success. While many 960 drivers love them, they are more maintenance intensive than the four-cylinder cars, and far less forgiving of indifferent maintenance.

In short, the 240-940 series Volvos were designed to be the equivalent of transport aircraft, not fighter jets. These cars get you where you need to go, safely.

They may be boring. Sometimes, though, "Boring is Good".

I'd hate to see you cook an engine, by stressing it beyond its design capacity.

Is there any way to "go gently", i.e., to avoid pushing the envelope?

Yours faithfully,

spook

With any turbo boost you must keep eye on fuel/air ratio, and if you think you can boost a 230 to those HP numbers without melting pistons I feel you are mislead.