Turbo Maps

[ezrollin]

I've been checking compressor maps to select a turbo for a 3.4/660 and noticed that some are not the same,for the same turbo listed. Guess someone mis-labeled them but it makes you wonder which one is right. Looks like the t61 has the hightest efficiency.Don't see much info on selecting the turbine, any suggestions ?

[ForcedFirebird]

I've been checking compressor maps to select a turbo for a 3.4/660 and noticed that some are not the same,for the same turbo listed. Guess someone mis-labeled them but it makes you wonder which one is right. Looks like the t61 has the hightest efficiency.Don't see much info on selecting the turbine, any suggestions ?

What turbo are you looking at? ie SSAutochrome, Garrett etc.

[1988GTU]

ForcedFB who/what turbo brand did you end up choosing?

[ezrollin]

What turbo are you looking at? ie SSAutochrome, Garrett etc.

Garrett !

[ForcedFirebird]

Here's what I got when I was looking for maps. This should help. T61 is a little big unless your motor is highly modded...
(Click here)
.

ForcedFB who/what turbo brand did you end up choosing?

It's in my sig. I went with an e-bay turbo that someone else here has been using for over 20,000 miles and has gotten well over 400RWHP out of it (and it was under $200). Click on the link in my signature if you have more questions, I don't want to clutter up the wrong thread . In the near future, I will post the install.

[ForcedFirebird]

The turbo I got was advertised as a 57 trim. However when I recieved it and opened it up to measure the compressor wheel, I discovered it was a 46 trim (big difference). Nonetheless, from what boostedrs has done with his, I am confident it will work for me.
Here's another useful link...
(Click here)

[1988GTU]

Here's what I got when I was looking for maps. This should help. T61 is a little big unless your motor is highly modded...
(Click here)
.

It's in my sig. I went with an e-bay turbo that someone else here has been using for over 20,000 miles and has gotten well over 400RWHP out of it (and it was under $200). Click on the link in my signature if you have more questions, I don't want to clutter up the wrong thread . In the near future, I will post the install.

ok..pm'ed ya

[ezrollin]

Hey,I saw boostedrs's post and that's what got me interested in a turboproject, so you got his turbo? Doing this from memory,my pr was 2.00 @14.7 and air was 43 lb/min. checking the map the t61 was 75% eff. and the to4e -57 was 70 % eff. I think the max cfm for the t61 was 60 and 49 for the to4e-57, Since I want a fast street vehicle and a 400hp limit the to4e-57 might be the ticket. There's the spool factor to consider and I don't know enough yet to make the choice.

[ForcedFirebird]

Hey,I saw boostedrs's post and that's what got me interested in a turboproject, so you got his turbo? Doing this from memory,my pr was 2.00 @14.7 and air was 43 lb/min. checking the map the t61 was 75% eff. and the to4e -57 was 70 % eff. I think the max cfm for the t61 was 60 and 49 for the to4e-57, Since I want a fast street vehicle and a 400hp limit the to4e-57 might be the ticket. There's the spool factor to consider and I don't know enough yet to make the choice.

Keep reading, then. Especially the Garrett link I gave you. The map is in LB/S not CFM. And do you realize that PR of 2 means 29.4PSI?! There is going to be some building before you get to those effeciency limits.
.
Try plugging "turbo maps" into Google, and start reading.

[timg]

When I did all of the compressor math, I found that the 60 trim T04E, 60-1, and GT35R had the best matching compressor maps for a street 3.4L DOHC motor. The GT35R would have virtually no lag with the potential for 600+ horsepower. The 60 trim and 60-1 have significantly lower power limits, but should still make good power with very little lag (depending on your turbine choice). If you're looking for fast spool and good street power, the GT35R is your best choice. For a cheaper option, a stage 3 or stage 5 turbine wheel combined with either the 60 trim or 60-1 would be a good option when paired with a minimum of the 0.82 a/r turbine housing (This would be a T3/T4 hybrid). If you want more power and don't mind the lag, a T4 P trim turbine might be the way to go on the hot side.

Tim

[timg]

Keep reading, then. Especially the Garrett link I gave you. The map is in LB/S not CFM. And do you realize that PR of 2 means 29.4PSI?! There is going to be some building before you get to those effeciency limits.
.
Try plugging "turbo maps" into Google, and start reading.

Actually, a PR of 2 is 14.7 psi gauge and 29.4 psi atmospheric. We normally use gauge pressure when talking about boost. I prefer to avoid that topic all together by using KPA instead. 0 kpa = perfect vacuum, 100 kpa = atmospheric pressure, 200 kpa = 14.7 psi

Tim

[ForcedFirebird]

Actually, a PR of 2 is 14.7 psi gauge and 29.4 psi atmospheric. We normally use gauge pressure when talking about boost. I prefer to avoid that topic all together by using KPA instead. 0 kpa = perfect vacuum, 100 kpa = atmospheric pressure, 200 kpa = 14.7 psi

Tim

Sorry, you are absolutely right. I should be using PSIG.
Either way he won't be reaching max efficiency without building for it (or having a perfect tune).
The turbo I selected is A/R .50 with a turbine of .63 which is a T3/T4 hybrid. Origionally got two M24's (T25) from my friends 300ZX which are Garretts with A/R .48 .63 turbine (60 trim), but when I found the imitation Garretts (e-bay) decided to use a large single for simplicity.
T04E is what I got and thought I was buying the 57 trim, when I recieved the turbo and measured the comp wheel it revealed a 46 trim (guess that's what I get for buying a Chinese brand). I know someone with the same turbo and maxed it at 16-18PSI reaching well over 400RWHP.
BTW : I would be willing to get rid of the Garretts, but I will tell you they need rebuilding.

[ezrollin]

Re checked my comps: 14.7= pr of 2 and af= 43 lbs/mins for a 3.4@6000rpms.The maps I used were Majestic turbos. The to4e with 46 trim shows a 60% eff. a t61 shows 75% eff. if I'm reading them right. T61=60 lbd/mins the to4e=49 lbs/mins. I'm limiting hp to 400[don't know if a 3.4[93-95]would hold up to more than that regularly.

[ForcedFirebird]

Re checked my comps: 14.7= pr of 2 and af= 43 lbs/mins for a 3.4@6000rpms.The maps I used were Majestic turbos. The to4e with 46 trim shows a 60% eff. a t61 shows 75% eff. if I'm reading them right. T61=60 lbd/mins the to4e=49 lbs/mins. I'm limiting hp to 400[don't know if a 3.4[93-95]would hold up to more than that regularly.

After more reading, I agree with Tmig, the GT35R or T04E with 60 trim. The T-61 is not going to be as streetable, and you will get lag. The T61 is what the SBC guys are using for a single setup. I also wish I would have gotten the 57 trim like I wanted, but the turbo will do for now since I am going to run out of injector at about 255HP anyways.

[ezrollin]

Like I said,turbos are new to me[practical expirence anyway] so I'm doing research,I have just gotten "Max Boost" and I'm reading it.Have done some searching on the net and have gotten various opinions,you can narrow it down to a couple of turbos and then it becomes personal choice. I have seen guys with 3.4 camaros using t61's and some using to4e's. THis is going into an s10 2wd blazer 1st gen;which is a little lighter,so performance should be as good or better. I've got a lot of reseach left to do,would like to hear from guys turboing 3.4's with iron heads.